/[magellan-source]/trunk/mkinitrd-magellan/busybox/shell/hush.c

Diff of /trunk/mkinitrd-magellan/busybox/shell/hush.c

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-revision 983 by niro,
Fri Apr 24 18:33:46 2009 UTC
+revision 984 by niro,
Sun May 30 11:32:42 2010 UTC
 Line 1
  /* vi: set sw=4 ts=4: */
  /*
-  * sh.c -- a prototype Bourne shell grammar parser
+  * A prototype Bourne shell grammar parser.
-  *      Intended to follow the original Thompson and Ritchie
+  * Intended to follow the original Thompson and Ritchie
-  *      "small and simple is beautiful" philosophy, which
+  * "small and simple is beautiful" philosophy, which
-  *      incidentally is a good match to today's BusyBox.
+  * incidentally is a good match to today's BusyBox.
   *
-  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
+  * Copyright (C) 2000,2001  Larry Doolittle <larry@doolittle.boa.org>
+  * Copyright (C) 2008,2009  Denys Vlasenko <vda.linux@googlemail.com>
   *
   * Credits:
   *      The parser routines proper are all original material, first
-Line 20
+Line 21
   *      rewrites.
   *
   * Other credits:
-  *      o_addchr() derived from similar w_addchar function in glibc-2.2.
+  *      o_addchr derived from similar w_addchar function in glibc-2.2.
-  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
+  *      parse_redirect, redirect_opt_num, and big chunks of main
-  *      and many builtins derived from contributions by Erik Andersen
+  *      and many builtins derived from contributions by Erik Andersen.
-  *      miscellaneous bugfixes from Matt Kraai.
+  *      Miscellaneous bugfixes from Matt Kraai.
   *
   * There are two big (and related) architecture differences between
   * this parser and the lash parser.  One is that this version is
-Line 36
+Line 37
   * handle the recursion implicit in the various substitutions, especially
   * across continuation lines.
   *
-  * Bash grammar not implemented: (how many of these were in original sh?)
+  * POSIX syntax not implemented:
-  *      $_
-  *      &> and >& redirection of stdout+stderr
-  *      Brace Expansion
-  *      Tilde Expansion
-  *      fancy forms of Parameter Expansion
   *      aliases
-  *      Arithmetic Expansion
   *      <(list) and >(list) Process Substitution
-  *      reserved words: select, function
+  *      Tilde Expansion
-  *      Here Documents ( << word )
+  *
-  *      Functions
+  * Bash stuff (optionally enabled):
-  * Major bugs:
+  *      &> and >& redirection of stdout+stderr
-  *      job handling woefully incomplete and buggy (improved --vda)
+  *      Brace Expansion
-  * to-do:
+  *      reserved words: [[ ]] function select
-  *      port selected bugfixes from post-0.49 busybox lash - done?
+  *      substrings ${var:1:5}
-  *      change { and } from special chars to reserved words
+  *      let EXPR [EXPR...]
-  *      builtins: return, trap, ulimit
+  *        Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
-  *      test magic exec with redirection only
+  *        If the last arg evaluates to 0, let returns 1; 0 otherwise.
-  *      check setting of global_argc and global_argv
+  *        NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
+  *      ((EXPR))
+  *        The EXPR is evaluated according to ARITHMETIC EVALUATION.
+  *        This is exactly equivalent to let "expression".
+  *
+  * TODOs:
+  *      grep for "TODO" and fix (some of them are easy)
+  *      builtins: ulimit
+  *      special variables (done: PWD)
   *      follow IFS rules more precisely, including update semantics
-  *      figure out what to do with backslash-newline
+  *      export builtin should be special, its arguments are assignments
-  *      propagate syntax errors, die on resource errors?
+  *          and therefore expansion of them should be "one-word" expansion:
-  *      continuation lines, both explicit and implicit - done?
+  *              $ export i=`echo 'a  b'` # export has one arg: "i=a  b"
-  *      memory leak finding and plugging - done?
+  *          compare with:
-  *      maybe change charmap[] to use 2-bit entries
+  *              $ ls i=`echo 'a  b'`     # ls has two args: "i=a" and "b"
+  *              ls: cannot access i=a: No such file or directory
+  *              ls: cannot access b: No such file or directory
+  *          Note1: same applies to local builtin.
+  *          Note2: bash 3.2.33(1) does this only if export word itself
+  *          is not quoted:
+  *              $ export i=`echo 'aaa  bbb'`; echo "$i"
+  *              aaa  bbb
+  *              $ "export" i=`echo 'aaa  bbb'`; echo "$i"
+  *              aaa
   *
   * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
   */
+ #include "busybox.h"  /* for APPLET_IS_NOFORK/NOEXEC */
- #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
+ #include <malloc.h>   /* for malloc_trim */
  #include <glob.h>
  /* #include <dmalloc.h> */
  #if ENABLE_HUSH_CASE
- #include <fnmatch.h>
+ # include <fnmatch.h>
  #endif
- #define HUSH_VER_STR "0.91"
+ #include "shell_common.h"
+ #include "builtin_read.h"
- #if !BB_MMU && ENABLE_HUSH_TICK
+ #include "math.h"
- //#undef ENABLE_HUSH_TICK
+ #include "match.h"
- //#define ENABLE_HUSH_TICK 0
+ #if ENABLE_HUSH_RANDOM_SUPPORT
- #warning On NOMMU, hush command substitution is dangerous.
+ # include "random.h"
- #warning Dont use it for commands which produce lots of output.
+ #else
- #warning For more info see shell/hush.c, generate_stream_from_list().
+ # define CLEAR_RANDOM_T(rnd) ((void)0)
+ #endif
+ #ifndef PIPE_BUF
+ # define PIPE_BUF 4096  /* amount of buffering in a pipe */
  #endif
- #if !BB_MMU && ENABLE_HUSH_JOB
- #undef ENABLE_HUSH_JOB
+ /* Build knobs */
- #define ENABLE_HUSH_JOB 0
+ #define LEAK_HUNTING 0
+ #define BUILD_AS_NOMMU 0
+ /* Enable/disable sanity checks. Ok to enable in production,
+  * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
+  * Keeping 1 for now even in released versions.
+  */
+ #define HUSH_DEBUG 1
+ /* Slightly bigger (+200 bytes), but faster hush.
+  * So far it only enables a trick with counting SIGCHLDs and forks,
+  * which allows us to do fewer waitpid's.
+  * (we can detect a case where neither forks were done nor SIGCHLDs happened
+  * and therefore waitpid will return the same result as last time)
+  */
+ #define ENABLE_HUSH_FAST 0
+ #if BUILD_AS_NOMMU
+ # undef BB_MMU
+ # undef USE_FOR_NOMMU
+ # undef USE_FOR_MMU
+ # define BB_MMU 0
+ # define USE_FOR_NOMMU(...) __VA_ARGS__
+ # define USE_FOR_MMU(...)
+ #endif
+ #define SKIP_definitions 1
+ #include "applet_tables.h"
+ #undef SKIP_definitions
+ #if NUM_APPLETS == 1
+ /* STANDALONE does not make sense, and won't compile */
+ # undef CONFIG_FEATURE_SH_STANDALONE
+ # undef ENABLE_FEATURE_SH_STANDALONE
+ # undef IF_FEATURE_SH_STANDALONE
+ # undef IF_NOT_FEATURE_SH_STANDALONE
+ # define ENABLE_FEATURE_SH_STANDALONE 0
+ # define IF_FEATURE_SH_STANDALONE(...)
+ # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
  #endif
  #if !ENABLE_HUSH_INTERACTIVE
- #undef ENABLE_FEATURE_EDITING
+ # undef ENABLE_FEATURE_EDITING
- #define ENABLE_FEATURE_EDITING 0
+ # define ENABLE_FEATURE_EDITING 0
- #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
+ # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
- #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
+ # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
  #endif
+ /* Do we support ANY keywords? */
- /* Keep unconditionally on for now */
+ #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
- #define HUSH_DEBUG 1
+ # define HAS_KEYWORDS 1
- /* In progress... */
+ # define IF_HAS_KEYWORDS(...) __VA_ARGS__
- #define ENABLE_HUSH_FUNCTIONS 0
+ # define IF_HAS_NO_KEYWORDS(...)
+ #else
+ # define HAS_KEYWORDS 0
+ # define IF_HAS_KEYWORDS(...)
+ # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
+ #endif
  /* If you comment out one of these below, it will be #defined later
   * to perform debug printfs to stderr: */
-Line 117
+Line 172
  #define debug_printf_subst(...)  do {} while (0)
  #define debug_printf_clean(...)  do {} while (0)
- #ifndef debug_printf
+ #define ERR_PTR ((void*)(long)1)
- #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
- #endif
- #ifndef debug_printf_parse
- #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
- #endif
- #ifndef debug_printf_exec
- #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
- #endif
- #ifndef debug_printf_env
- #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
- #endif
- #ifndef debug_printf_jobs
- #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
- #define DEBUG_JOBS 1
- #else
- #define DEBUG_JOBS 0
- #endif
- #ifndef debug_printf_expand
- #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
- #define DEBUG_EXPAND 1
- #else
- #define DEBUG_EXPAND 0
- #endif
- #ifndef debug_printf_glob
- #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
- #define DEBUG_GLOB 1
- #else
- #define DEBUG_GLOB 0
- #endif
- #ifndef debug_printf_list
+ #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
- #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
- #endif
- #ifndef debug_printf_subst
+ #define SPECIAL_VAR_SYMBOL 3
- #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
- #endif
- #ifndef debug_printf_clean
+ struct variable;
- /* broken, of course, but OK for testing */
- static const char *indenter(int i)
- {
- 	static const char blanks[] ALIGN1 =
- 		"                                    ";
- 	return &blanks[sizeof(blanks) - i - 1];
- }
- #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
- #define DEBUG_CLEAN 1
- #endif
- #if DEBUG_EXPAND
+ static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
- static void debug_print_strings(const char *prefix, char **vv)
- {
- 	fprintf(stderr, "%s:\n", prefix);
- 	while (*vv)
- 		fprintf(stderr, " '%s'\n", *vv++);
- }
- #else
- #define debug_print_strings(prefix, vv) ((void)0)
- #endif
- /*
+ /* This supports saving pointers malloced in vfork child,
-  * Leak hunting. Use hush_leaktool.sh for post-processing.
+  * to be freed in the parent.
   */
- #ifdef FOR_HUSH_LEAKTOOL
+ #if !BB_MMU
- /* suppress "warning: no previous prototype..." */
+ typedef struct nommu_save_t {
- void *xxmalloc(int lineno, size_t size);
+ 	char **new_env;
- void *xxrealloc(int lineno, void *ptr, size_t size);
+ 	struct variable *old_vars;
- char *xxstrdup(int lineno, const char *str);
+ 	char **argv;
- void xxfree(void *ptr);
+ 	char **argv_from_re_execing;
- void *xxmalloc(int lineno, size_t size)
+ } nommu_save_t;
- {
- 	void *ptr = xmalloc((size + 0xff) & ~0xff);
- 	fprintf(stderr, "line %d: malloc %p\n", lineno, ptr);
- 	return ptr;
- }
- void *xxrealloc(int lineno, void *ptr, size_t size)
- {
- 	ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
- 	fprintf(stderr, "line %d: realloc %p\n", lineno, ptr);
- 	return ptr;
- }
- char *xxstrdup(int lineno, const char *str)
- {
- 	char *ptr = xstrdup(str);
- 	fprintf(stderr, "line %d: strdup %p\n", lineno, ptr);
- 	return ptr;
- }
- void xxfree(void *ptr)
- {
- 	fprintf(stderr, "free %p\n", ptr);
- 	free(ptr);
- }
- #define xmalloc(s)     xxmalloc(__LINE__, s)
- #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
- #define xstrdup(s)     xxstrdup(__LINE__, s)
- #define free(p)        xxfree(p)
- #endif
- /* Do we support ANY keywords? */
- #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
- #define HAS_KEYWORDS 1
- #define IF_HAS_KEYWORDS(...) __VA_ARGS__
- #define IF_HAS_NO_KEYWORDS(...)
- #else
- #define HAS_KEYWORDS 0
- #define IF_HAS_KEYWORDS(...)
- #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
  #endif
- #define SPECIAL_VAR_SYMBOL       3
- #define PARSEFLAG_EXIT_FROM_LOOP 1
- typedef enum redir_type {
- 	REDIRECT_INPUT     = 1,
- 	REDIRECT_OVERWRITE = 2,
- 	REDIRECT_APPEND    = 3,
- 	REDIRECT_HEREIS    = 4,
- 	REDIRECT_IO        = 5
- } redir_type;
- /* The descrip member of this structure is only used to make
-  * debugging output pretty */
- static const struct {
- 	int mode;
- 	signed char default_fd;
- 	char descrip[3];
- } redir_table[] = {
- 	{ 0,                         0, "()" },
- 	{ O_RDONLY,                  0, "<"  },
- 	{ O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
- 	{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
- 	{ O_RDONLY,                 -1, "<<" },
- 	{ O_RDWR,                    1, "<>" }
- };
- typedef enum pipe_style {
- 	PIPE_SEQ = 1,
- 	PIPE_AND = 2,
- 	PIPE_OR  = 3,
- 	PIPE_BG  = 4,
- } pipe_style;
  typedef enum reserved_style {
  	RES_NONE  = 0,
  #if ENABLE_HUSH_IF
-Line 290 
 typedef enum reserved_style {
+Line 215 
 typedef enum reserved_style {
  #endif
  #if ENABLE_HUSH_CASE
  	RES_CASE  ,
- 	/* two pseudo-keywords support contrived "case" syntax: */
+ 	/* three pseudo-keywords support contrived "case" syntax: */
- 	RES_MATCH , /* "word)" */
+ 	RES_CASE_IN,   /* "case ... IN", turns into RES_MATCH when IN is observed */
- 	RES_CASEI , /* "this command is inside CASE" */
+ 	RES_MATCH ,    /* "word)" */
+ 	RES_CASE_BODY, /* "this command is inside CASE" */
  	RES_ESAC  ,
  #endif
  	RES_XXXX  ,
  	RES_SNTX
  } reserved_style;
+ typedef struct o_string {
+ 	char *data;
+ 	int length; /* position where data is appended */
+ 	int maxlen;
+ 	/* Protect newly added chars against globbing
+ 	 * (by prepending \ to *, ?, [, \) */
+ 	smallint o_escape;
+ 	smallint o_glob;
+ 	/* At least some part of the string was inside '' or "",
+ 	 * possibly empty one: word"", wo''rd etc. */
+ 	smallint o_quoted;
+ 	smallint has_empty_slot;
+ 	smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
+ } o_string;
+ enum {
+ 	MAYBE_ASSIGNMENT = 0,
+ 	DEFINITELY_ASSIGNMENT = 1,
+ 	NOT_ASSIGNMENT = 2,
+ 	WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
+ };
+ /* Used for initialization: o_string foo = NULL_O_STRING; */
+ #define NULL_O_STRING { NULL }
+ /* I can almost use ordinary FILE*.  Is open_memstream() universally
+  * available?  Where is it documented? */
+ typedef struct in_str {
+ 	const char *p;
+ 	/* eof_flag=1: last char in ->p is really an EOF */
+ 	char eof_flag; /* meaningless if ->p == NULL */
+ 	char peek_buf[2];
+ #if ENABLE_HUSH_INTERACTIVE
+ 	smallint promptme;
+ 	smallint promptmode; /* 0: PS1, 1: PS2 */
+ #endif
+ 	FILE *file;
+ 	int (*get) (struct in_str *) FAST_FUNC;
+ 	int (*peek) (struct in_str *) FAST_FUNC;
+ } in_str;
+ #define i_getch(input) ((input)->get(input))
+ #define i_peek(input) ((input)->peek(input))
+ /* The descrip member of this structure is only used to make
+  * debugging output pretty */
+ static const struct {
+ 	int mode;
+ 	signed char default_fd;
+ 	char descrip[3];
+ } redir_table[] = {
+ 	{ O_RDONLY,                  0, "<"  },
+ 	{ O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
+ 	{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
+ 	{ O_CREAT|O_RDWR,            1, "<>" },
+ 	{ O_RDONLY,                  0, "<<" },
+ /* Should not be needed. Bogus default_fd helps in debugging */
+ /*	{ O_RDONLY,                 77, "<<" }, */
+ };
  struct redir_struct {
  	struct redir_struct *next;
  	char *rd_filename;          /* filename */
- 	int fd;                     /* file descriptor being redirected */
+ 	int rd_fd;                  /* fd to redirect */
- 	int dup;                    /* -1, or file descriptor being duplicated */
+ 	/* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
- 	smallint /*enum redir_type*/ rd_type;
+ 	int rd_dup;
+ 	smallint rd_type;           /* (enum redir_type) */
+ 	/* note: for heredocs, rd_filename contains heredoc delimiter,
+ 	 * and subsequently heredoc itself; and rd_dup is a bitmask:
+ 	 * bit 0: do we need to trim leading tabs?
+ 	 * bit 1: is heredoc quoted (<<'delim' syntax) ?
+ 	 */
  };
+ typedef enum redir_type {
+ 	REDIRECT_INPUT     = 0,
+ 	REDIRECT_OVERWRITE = 1,
+ 	REDIRECT_APPEND    = 2,
+ 	REDIRECT_IO        = 3,
+ 	REDIRECT_HEREDOC   = 4,
+ 	REDIRECT_HEREDOC2  = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
+ 	REDIRFD_CLOSE      = -3,
+ 	REDIRFD_SYNTAX_ERR = -2,
+ 	REDIRFD_TO_FILE    = -1,
+ 	/* otherwise, rd_fd is redirected to rd_dup */
+ 	HEREDOC_SKIPTABS = 1,
+ 	HEREDOC_QUOTED   = 2,
+ } redir_type;
  struct command {
  	pid_t pid;                  /* 0 if exited */
  	int assignment_cnt;         /* how many argv[i] are assignments? */
  	smallint is_stopped;        /* is the command currently running? */
- 	smallint grp_type;
+ 	smallint cmd_type;          /* CMD_xxx */
- 	struct pipe *group;         /* if non-NULL, this "prog" is {} group,
+ #define CMD_NORMAL   0
- 	                             * subshell, or a compound statement */
+ #define CMD_SUBSHELL 1
+ /* used for "[[ EXPR ]]" */
+ #if ENABLE_HUSH_BASH_COMPAT
+ # define CMD_SINGLEWORD_NOGLOB 2
+ #endif
+ /* used for "export noglob=* glob* a=`echo a b`" */
+ //#define CMD_SINGLEWORD_NOGLOB_COND 3
+ // It is hard to implement correctly, it adds significant amounts of tricky code,
+ // and all this is only useful for really obscure export statements
+ // almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
+ // guards the code which implements it, but I have doubts it works
+ // in all cases (especially with mixed globbed/non-globbed arguments)
+ #if ENABLE_HUSH_FUNCTIONS
+ # define CMD_FUNCDEF 3
+ #endif
+ 	/* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
+ 	struct pipe *group;
+ #if !BB_MMU
+ 	char *group_as_string;
+ #endif
+ #if ENABLE_HUSH_FUNCTIONS
+ 	struct function *child_func;
+ /* This field is used to prevent a bug here:
+  * while...do f1() {a;}; f1; f1() {b;}; f1; done
+  * When we execute "f1() {a;}" cmd, we create new function and clear
+  * cmd->group, cmd->group_as_string, cmd->argv[0].
+  * When we execute "f1() {b;}", we notice that f1 exists,
+  * and that its "parent cmd" struct is still "alive",
+  * we put those fields back into cmd->xxx
+  * (struct function has ->parent_cmd ptr to facilitate that).
+  * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
+  * Without this trick, loop would execute a;b;b;b;...
+  * instead of correct sequence a;b;a;b;...
+  * When command is freed, it severs the link
+  * (sets ->child_func->parent_cmd to NULL).
+  */
+ #endif
  	char **argv;                /* command name and arguments */
- 	struct redir_struct *redirects; /* I/O redirections */
- };
  /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
   * and on execution these are substituted with their values.
   * Substitution can make _several_ words out of one argv[n]!
   * Example: argv[0]=='.^C*^C.' here: echo .$*.
   * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
   */
- #define GRP_NORMAL   0
+ 	struct redir_struct *redirects; /* I/O redirections */
- #define GRP_SUBSHELL 1
+ };
- #if ENABLE_HUSH_FUNCTIONS
+ /* Is there anything in this command at all? */
- #define GRP_FUNCTION 2
+ #define IS_NULL_CMD(cmd) \
- #endif
+ 	(!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
  struct pipe {
  	struct pipe *next;
- 	int num_cmds;               /* total number of commands in job */
+ 	int num_cmds;               /* total number of commands in pipe */
  	int alive_cmds;             /* number of commands running (not exited) */
  	int stopped_cmds;           /* number of commands alive, but stopped */
  #if ENABLE_HUSH_JOB
-Line 344 
 struct pipe {
+Line 389 
 struct pipe {
  	IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
  	IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
  };
+ typedef enum pipe_style {
+ 	PIPE_SEQ = 1,
+ 	PIPE_AND = 2,
+ 	PIPE_OR  = 3,
+ 	PIPE_BG  = 4,
+ } pipe_style;
+ /* Is there anything in this pipe at all? */
+ #define IS_NULL_PIPE(pi) \
+ 	((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
  /* This holds pointers to the various results of parsing */
  struct parse_context {
- 	struct command *command;
+ 	/* linked list of pipes */
  	struct pipe *list_head;
+ 	/* last pipe (being constructed right now) */
  	struct pipe *pipe;
+ 	/* last command in pipe (being constructed right now) */
+ 	struct command *command;
+ 	/* last redirect in command->redirects list */
  	struct redir_struct *pending_redirect;
+ #if !BB_MMU
+ 	o_string as_string;
+ #endif
  #if HAS_KEYWORDS
  	smallint ctx_res_w;
  	smallint ctx_inverted; /* "! cmd | cmd" */
  #if ENABLE_HUSH_CASE
  	smallint ctx_dsemicolon; /* ";;" seen */
  #endif
- 	int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
+ 	/* bitmask of FLAG_xxx, for figuring out valid reserved words */
+ 	int old_flag;
+ 	/* group we are enclosed in:
+ 	 * example: "if pipe1; pipe2; then pipe3; fi"
+ 	 * when we see "if" or "then", we malloc and copy current context,
+ 	 * and make ->stack point to it. then we parse pipeN.
+ 	 * when closing "then" / fi" / whatever is found,
+ 	 * we move list_head into ->stack->command->group,
+ 	 * copy ->stack into current context, and delete ->stack.
+ 	 * (parsing of { list } and ( list ) doesn't use this method)
+ 	 */
  	struct parse_context *stack;
  #endif
  };
-Line 371 
 struct parse_context {
+Line 442 
 struct parse_context {
  struct variable {
  	struct variable *next;
  	char *varstr;        /* points to "name=" portion */
+ #if ENABLE_HUSH_LOCAL
+ 	unsigned func_nest_level;
+ #endif
  	int max_len;         /* if > 0, name is part of initial env; else name is malloced */
  	smallint flg_export; /* putenv should be done on this var */
  	smallint flg_read_only;
  };
- typedef struct o_string {
- 	char *data;
- 	int length; /* position where data is appended */
- 	int maxlen;
- 	/* Misnomer! it's not "quoting", it's "protection against globbing"!
- 	 * (by prepending \ to *, ?, [ and to \ too) */
- 	smallint o_quote;
- 	smallint o_glob;
- 	smallint nonnull;
- 	smallint has_empty_slot;
- 	smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
- } o_string;
- enum {
- 	MAYBE_ASSIGNMENT = 0,
- 	DEFINITELY_ASSIGNMENT = 1,
- 	NOT_ASSIGNMENT = 2,
- 	WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
- };
- /* Used for initialization: o_string foo = NULL_O_STRING; */
- #define NULL_O_STRING { NULL }
- /* I can almost use ordinary FILE*.  Is open_memstream() universally
-  * available?  Where is it documented? */
- typedef struct in_str {
- 	const char *p;
- 	/* eof_flag=1: last char in ->p is really an EOF */
- 	char eof_flag; /* meaningless if ->p == NULL */
- 	char peek_buf[2];
- #if ENABLE_HUSH_INTERACTIVE
- 	smallint promptme;
- 	smallint promptmode; /* 0: PS1, 1: PS2 */
- #endif
- 	FILE *file;
- 	int (*get) (struct in_str *);
- 	int (*peek) (struct in_str *);
- } in_str;
- #define i_getch(input) ((input)->get(input))
- #define i_peek(input) ((input)->peek(input))
- enum {
- 	CHAR_ORDINARY           = 0,
- 	CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
- 	CHAR_IFS                = 2, /* treated as ordinary if quoted */
- 	CHAR_SPECIAL            = 3, /* example: $ */
- };
  enum {
  	BC_BREAK = 1,
  	BC_CONTINUE = 2,
  };
+ #if ENABLE_HUSH_FUNCTIONS
+ struct function {
+ 	struct function *next;
+ 	char *name;
+ 	struct command *parent_cmd;
+ 	struct pipe *body;
+ # if !BB_MMU
+ 	char *body_as_string;
+ # endif
+ };
+ #endif
  /* "Globals" within this file */
  /* Sorted roughly by size (smaller offsets == smaller code) */
  struct globals {
+ 	/* interactive_fd != 0 means we are an interactive shell.
+ 	 * If we are, then saved_tty_pgrp can also be != 0, meaning
+ 	 * that controlling tty is available. With saved_tty_pgrp == 0,
+ 	 * job control still works, but terminal signals
+ 	 * (^C, ^Z, ^Y, ^\) won't work at all, and background
+ 	 * process groups can only be created with "cmd &".
+ 	 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
+ 	 * to give tty to the foreground process group,
+ 	 * and will take it back when the group is stopped (^Z)
+ 	 * or killed (^C).
+ 	 */
  #if ENABLE_HUSH_INTERACTIVE
  	/* 'interactive_fd' is a fd# open to ctty, if we have one
  	 * _AND_ if we decided to act interactively */
  	int interactive_fd;
  	const char *PS1;
  	const char *PS2;
+ # define G_interactive_fd (G.interactive_fd)
+ #else
+ # define G_interactive_fd 0
  #endif
  #if ENABLE_FEATURE_EDITING
  	line_input_t *line_input_state;
  #endif
  	pid_t root_pid;
+ 	pid_t root_ppid;
  	pid_t last_bg_pid;
+ #if ENABLE_HUSH_RANDOM_SUPPORT
+ 	random_t random_gen;
+ #endif
  #if ENABLE_HUSH_JOB
  	int run_list_level;
- 	pid_t saved_tty_pgrp;
  	int last_jobid;
+ 	pid_t saved_tty_pgrp;
  	struct pipe *job_list;
- 	struct pipe *toplevel_list;
+ # define G_saved_tty_pgrp (G.saved_tty_pgrp)
- 	smallint ctrl_z_flag;
+ #else
+ # define G_saved_tty_pgrp 0
  #endif
+ 	smallint flag_SIGINT;
  #if ENABLE_HUSH_LOOPS
  	smallint flag_break_continue;
  #endif
+ #if ENABLE_HUSH_FUNCTIONS
+ 	/* 0: outside of a function (or sourced file)
+ 	 * -1: inside of a function, ok to use return builtin
+ 	 * 1: return is invoked, skip all till end of func
+ 	 */
+ 	smallint flag_return_in_progress;
+ #endif
  	smallint fake_mode;
- 	/* these three support $?, $#, and $1 */
+ 	smallint exiting; /* used to prevent EXIT trap recursion */
- 	smalluint last_return_code;
+ 	/* These four support $?, $#, and $1 */
- 	/* is global_argv and global_argv[1..n] malloced? (note: not [0]) */
+ 	smalluint last_exitcode;
+ 	/* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
  	smalluint global_args_malloced;
+ 	smalluint inherited_set_is_saved;
  	/* how many non-NULL argv's we have. NB: $# + 1 */
  	int global_argc;
  	char **global_argv;
+ #if !BB_MMU
+ 	char *argv0_for_re_execing;
+ #endif
  #if ENABLE_HUSH_LOOPS
  	unsigned depth_break_continue;
  	unsigned depth_of_loop;
-Line 471 
 struct globals {
+Line 542 
 struct globals {
  	const char *cwd;
  	struct variable *top_var; /* = &G.shell_ver (set in main()) */
  	struct variable shell_ver;
- #if ENABLE_FEATURE_SH_STANDALONE
+ #if ENABLE_HUSH_FUNCTIONS
- 	struct nofork_save_area nofork_save;
+ 	struct function *top_func;
- #endif
+ # if ENABLE_HUSH_LOCAL
- #if ENABLE_HUSH_JOB
+ 	struct variable **shadowed_vars_pp;
- 	sigjmp_buf toplevel_jb;
+ 	unsigned func_nest_level;
+ # endif
+ #endif
+ 	/* Signal and trap handling */
+ #if ENABLE_HUSH_FAST
+ 	unsigned count_SIGCHLD;
+ 	unsigned handled_SIGCHLD;
+ 	smallint we_have_children;
+ #endif
+ 	/* which signals have non-DFL handler (even with no traps set)? */
+ 	unsigned non_DFL_mask;
+ 	char **traps; /* char *traps[NSIG] */
+ 	sigset_t blocked_set;
+ 	sigset_t inherited_set;
+ #if HUSH_DEBUG
+ 	unsigned long memleak_value;
+ 	int debug_indent;
  #endif
- 	unsigned char charmap[256];
+ 	char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
- 	char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
  };
  #define G (*ptr_to_globals)
  /* Not #defining name to G.name - this quickly gets unwieldy
   * (too many defines). Also, I actually prefer to see when a variable
-Line 490 
 struct globals {
+Line 575 
 struct globals {
  } while (0)
- #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
+ /* Function prototypes for builtins */
+ static int builtin_cd(char **argv) FAST_FUNC;
+ static int builtin_echo(char **argv) FAST_FUNC;
+ static int builtin_eval(char **argv) FAST_FUNC;
+ static int builtin_exec(char **argv) FAST_FUNC;
+ static int builtin_exit(char **argv) FAST_FUNC;
+ static int builtin_export(char **argv) FAST_FUNC;
+ #if ENABLE_HUSH_JOB
+ static int builtin_fg_bg(char **argv) FAST_FUNC;
+ static int builtin_jobs(char **argv) FAST_FUNC;
+ #endif
+ #if ENABLE_HUSH_HELP
+ static int builtin_help(char **argv) FAST_FUNC;
+ #endif
+ #if ENABLE_HUSH_LOCAL
+ static int builtin_local(char **argv) FAST_FUNC;
+ #endif
+ #if HUSH_DEBUG
+ static int builtin_memleak(char **argv) FAST_FUNC;
+ #endif
+ #if ENABLE_PRINTF
+ static int builtin_printf(char **argv) FAST_FUNC;
+ #endif
+ static int builtin_pwd(char **argv) FAST_FUNC;
+ static int builtin_read(char **argv) FAST_FUNC;
+ static int builtin_set(char **argv) FAST_FUNC;
+ static int builtin_shift(char **argv) FAST_FUNC;
+ static int builtin_source(char **argv) FAST_FUNC;
+ static int builtin_test(char **argv) FAST_FUNC;
+ static int builtin_trap(char **argv) FAST_FUNC;
+ static int builtin_type(char **argv) FAST_FUNC;
+ static int builtin_true(char **argv) FAST_FUNC;
+ static int builtin_umask(char **argv) FAST_FUNC;
+ static int builtin_unset(char **argv) FAST_FUNC;
+ static int builtin_wait(char **argv) FAST_FUNC;
+ #if ENABLE_HUSH_LOOPS
+ static int builtin_break(char **argv) FAST_FUNC;
+ static int builtin_continue(char **argv) FAST_FUNC;
+ #endif
+ #if ENABLE_HUSH_FUNCTIONS
+ static int builtin_return(char **argv) FAST_FUNC;
+ #endif
- #if 1
+ /* Table of built-in functions.  They can be forked or not, depending on
- /* Normal */
+  * context: within pipes, they fork.  As simple commands, they do not.
- static void syntax(const char *msg)
+  * When used in non-forking context, they can change global variables
- {
+  * in the parent shell process.  If forked, of course they cannot.
- #if ENABLE_HUSH_INTERACTIVE
+  * For example, 'unset foo | whatever' will parse and run, but foo will
- 	/* Was using fancy stuff:
+  * still be set at the end. */
- 	 * (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
+ struct built_in_command {
- 	 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
+ 	const char *cmd;
- 	void FAST_FUNC (*fp)(const char *s, ...);
+ 	int (*function)(char **argv) FAST_FUNC;
- 	fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die);
+ #if ENABLE_HUSH_HELP
- 	fp(msg ? "%s: %s" : "syntax error", "syntax error", msg);
+ 	const char *descr;
+ # define BLTIN(cmd, func, help) { cmd, func, help }
  #else
- 	bb_error_msg_and_die(msg ? "%s: %s" : "syntax error", "syntax error", msg);
+ # define BLTIN(cmd, func, help) { cmd, func }
  #endif
- }
+ };
+ static const struct built_in_command bltins1[] = {
+ 	BLTIN("."        , builtin_source  , "Run commands in a file"),
+ 	BLTIN(":"        , builtin_true    , NULL),
+ #if ENABLE_HUSH_JOB
+ 	BLTIN("bg"       , builtin_fg_bg   , "Resume a job in the background"),
+ #endif
+ #if ENABLE_HUSH_LOOPS
+ 	BLTIN("break"    , builtin_break   , "Exit from a loop"),
+ #endif
+ 	BLTIN("cd"       , builtin_cd      , "Change directory"),
+ #if ENABLE_HUSH_LOOPS
+ 	BLTIN("continue" , builtin_continue, "Start new loop iteration"),
+ #endif
+ 	BLTIN("eval"     , builtin_eval    , "Construct and run shell command"),
+ 	BLTIN("exec"     , builtin_exec    , "Execute command, don't return to shell"),
+ 	BLTIN("exit"     , builtin_exit    , "Exit"),
+ 	BLTIN("export"   , builtin_export  , "Set environment variables"),
+ #if ENABLE_HUSH_JOB
+ 	BLTIN("fg"       , builtin_fg_bg   , "Bring job into the foreground"),
+ #endif
+ #if ENABLE_HUSH_HELP
+ 	BLTIN("help"     , builtin_help    , NULL),
+ #endif
+ #if ENABLE_HUSH_JOB
+ 	BLTIN("jobs"     , builtin_jobs    , "List jobs"),
+ #endif
+ #if ENABLE_HUSH_LOCAL
+ 	BLTIN("local"    , builtin_local   , "Set local variables"),
+ #endif
+ #if HUSH_DEBUG
+ 	BLTIN("memleak"  , builtin_memleak , NULL),
+ #endif
+ 	BLTIN("read"     , builtin_read    , "Input into variable"),
+ #if ENABLE_HUSH_FUNCTIONS
+ 	BLTIN("return"   , builtin_return  , "Return from a function"),
+ #endif
+ 	BLTIN("set"      , builtin_set     , "Set/unset positional parameters"),
+ 	BLTIN("shift"    , builtin_shift   , "Shift positional parameters"),
+ 	BLTIN("trap"     , builtin_trap    , "Trap signals"),
+ 	BLTIN("type"     , builtin_type    , "Write a description of command type"),
+ //	BLTIN("ulimit"   , builtin_ulimit  , "Control resource limits"),
+ 	BLTIN("umask"    , builtin_umask   , "Set file creation mask"),
+ 	BLTIN("unset"    , builtin_unset   , "Unset variables"),
+ 	BLTIN("wait"     , builtin_wait    , "Wait for process"),
+ };
+ /* For now, echo and test are unconditionally enabled.
+  * Maybe make it configurable? */
+ static const struct built_in_command bltins2[] = {
+ 	BLTIN("["        , builtin_test    , NULL),
+ 	BLTIN("echo"     , builtin_echo    , NULL),
+ #if ENABLE_PRINTF
+ 	BLTIN("printf"   , builtin_printf  , NULL),
+ #endif
+ 	BLTIN("pwd"      , builtin_pwd     , NULL),
+ 	BLTIN("test"     , builtin_test    , NULL),
+ };
+ /* Debug printouts.
+  */
+ #if HUSH_DEBUG
+ /* prevent disasters with G.debug_indent < 0 */
+ # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
+ # define debug_enter() (G.debug_indent++)
+ # define debug_leave() (G.debug_indent--)
  #else
- /* Debug */
+ # define indent()      ((void)0)
- static void syntax_lineno(int line)
+ # define debug_enter() ((void)0)
- {
+ # define debug_leave() ((void)0)
- #if ENABLE_HUSH_INTERACTIVE
+ #endif
- 	void FAST_FUNC (*fp)(const char *s, ...);
- 	fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die);
+ #ifndef debug_printf
- 	fp("syntax error hush.c:%d", line);
+ # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
+ #endif
+ #ifndef debug_printf_parse
+ # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
+ #endif
+ #ifndef debug_printf_exec
+ #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
+ #endif
+ #ifndef debug_printf_env
+ # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
+ #endif
+ #ifndef debug_printf_jobs
+ # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
+ # define DEBUG_JOBS 1
  #else
- 	bb_error_msg_and_die("syntax error hush.c:%d", line);
+ # define DEBUG_JOBS 0
  #endif
- }
- #define syntax(str) syntax_lineno(__LINE__)
+ #ifndef debug_printf_expand
+ # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
+ # define DEBUG_EXPAND 1
+ #else
+ # define DEBUG_EXPAND 0
  #endif
- /* Index of subroutines: */
+ #ifndef debug_printf_glob
- /*  in_str manipulations: */
+ # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
- static int static_get(struct in_str *i);
+ # define DEBUG_GLOB 1
- static int static_peek(struct in_str *i);
+ #else
- static int file_get(struct in_str *i);
+ # define DEBUG_GLOB 0
- static int file_peek(struct in_str *i);
- static void setup_file_in_str(struct in_str *i, FILE *f);
- static void setup_string_in_str(struct in_str *i, const char *s);
- /*  "run" the final data structures: */
- #if !defined(DEBUG_CLEAN)
- #define free_pipe_list(head, indent) free_pipe_list(head)
- #define free_pipe(pi, indent)        free_pipe(pi)
- #endif
- static int free_pipe_list(struct pipe *head, int indent);
- static int free_pipe(struct pipe *pi, int indent);
- /*  really run the final data structures: */
- typedef struct nommu_save_t {
- 	char **new_env;
- 	char **old_env;
- 	char **argv;
- } nommu_save_t;
- #if BB_MMU
- #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
- 	pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
- #define pseudo_exec(nommu_save, command, argv_expanded) \
- 	pseudo_exec(command, argv_expanded)
  #endif
- static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
- static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN;
+ #ifndef debug_printf_list
- static int setup_redirects(struct command *prog, int squirrel[]);
+ # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
- static int run_list(struct pipe *pi);
- static int run_pipe(struct pipe *pi);
- /*   data structure manipulation: */
- static int setup_redirect(struct parse_context *ctx, int fd, redir_type style, struct in_str *input);
- static void initialize_context(struct parse_context *ctx);
- static int done_word(o_string *dest, struct parse_context *ctx);
- static int done_command(struct parse_context *ctx);
- static void done_pipe(struct parse_context *ctx, pipe_style type);
- /*   primary string parsing: */
- static int redirect_dup_num(struct in_str *input);
- static int redirect_opt_num(o_string *o);
- #if ENABLE_HUSH_TICK
- static int process_command_subs(o_string *dest,
- 		struct in_str *input, const char *subst_end);
  #endif
- static int parse_group(o_string *dest, struct parse_context *ctx, struct in_str *input, int ch);
- static const char *lookup_param(const char *src);
+ #ifndef debug_printf_subst
- static int handle_dollar(o_string *dest,
+ # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
- 		struct in_str *input);
+ #endif
- static int parse_stream(o_string *dest, struct parse_context *ctx, struct in_str *input0, const char *end_trigger);
- /*   setup: */
+ #ifndef debug_printf_clean
- static int parse_and_run_stream(struct in_str *inp, int parse_flag);
+ # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
- static int parse_and_run_string(const char *s, int parse_flag);
+ # define DEBUG_CLEAN 1
- static int parse_and_run_file(FILE *f);
- /*   job management: */
- static int checkjobs(struct pipe* fg_pipe);
- #if ENABLE_HUSH_JOB
- static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
- static void insert_bg_job(struct pipe *pi);
- static void remove_bg_job(struct pipe *pi);
- static void delete_finished_bg_job(struct pipe *pi);
  #else
- int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
+ # define DEBUG_CLEAN 0
  #endif
- /*     local variable support */
- static char **expand_strvec_to_strvec(char **argv);
- /* used for eval */
- static char *expand_strvec_to_string(char **argv);
- /* used for expansion of right hand of assignments */
- static char *expand_string_to_string(const char *str);
- static struct variable *get_local_var(const char *name);
- static int set_local_var(char *str, int flg_export);
- static void unset_local_var(const char *name);
+ #if DEBUG_EXPAND
+ static void debug_print_strings(const char *prefix, char **vv)
+ {
+ 	indent();
+ 	fprintf(stderr, "%s:\n", prefix);
+ 	while (*vv)
+ 		fprintf(stderr, " '%s'\n", *vv++);
+ }
+ #else
+ # define debug_print_strings(prefix, vv) ((void)0)
+ #endif
+ /* Leak hunting. Use hush_leaktool.sh for post-processing.
+  */
+ #if LEAK_HUNTING
+ static void *xxmalloc(int lineno, size_t size)
+ {
+ 	void *ptr = xmalloc((size + 0xff) & ~0xff);
+ 	fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
+ 	return ptr;
+ }
+ static void *xxrealloc(int lineno, void *ptr, size_t size)
+ {
+ 	ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
+ 	fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
+ 	return ptr;
+ }
+ static char *xxstrdup(int lineno, const char *str)
+ {
+ 	char *ptr = xstrdup(str);
+ 	fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
+ 	return ptr;
+ }
+ static void xxfree(void *ptr)
+ {
+ 	fdprintf(2, "free %p\n", ptr);
+ 	free(ptr);
+ }
+ #define xmalloc(s)     xxmalloc(__LINE__, s)
+ #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
+ #define xstrdup(s)     xxstrdup(__LINE__, s)
+ #define free(p)        xxfree(p)
+ #endif
- static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
+ /* Syntax and runtime errors. They always abort scripts.
+  * In interactive use they usually discard unparsed and/or unexecuted commands
+  * and return to the prompt.
+  * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
+  */
+ #if HUSH_DEBUG < 2
+ # define die_if_script(lineno, ...)             die_if_script(__VA_ARGS__)
+ # define syntax_error(lineno, msg)              syntax_error(msg)
+ # define syntax_error_at(lineno, msg)           syntax_error_at(msg)
+ # define syntax_error_unterm_ch(lineno, ch)     syntax_error_unterm_ch(ch)
+ # define syntax_error_unterm_str(lineno, s)     syntax_error_unterm_str(s)
+ # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
+ #endif
- static int glob_needed(const char *s)
+ static void die_if_script(unsigned lineno, const char *fmt, ...)
  {
- 	while (*s) {
+ 	va_list p;
- 		if (*s == '\\')
- 			s++;
+ #if HUSH_DEBUG >= 2
- 		if (*s == '*' || *s == '[' || *s == '?')
+ 	bb_error_msg("hush.c:%u", lineno);
- 			return 1;
+ #endif
- 		s++;
+ 	va_start(p, fmt);
- 	}
+ 	bb_verror_msg(fmt, p, NULL);
- 	return 0;
+ 	va_end(p);
+ 	if (!G_interactive_fd)
+ 		xfunc_die();
  }
- static int is_assignment(const char *s)
+ static void syntax_error(unsigned lineno, const char *msg)
  {
- 	if (!s || !(isalpha(*s) || *s == '_'))
+ 	if (msg)
- 		return 0;
+ 		die_if_script(lineno, "syntax error: %s", msg);
- 	s++;
+ 	else
- 	while (isalnum(*s) || *s == '_')
+ 		die_if_script(lineno, "syntax error", NULL);
- 		s++;
+ }
- 	return *s == '=';
+ static void syntax_error_at(unsigned lineno, const char *msg)
+ {
+ 	die_if_script(lineno, "syntax error at '%s'", msg);
+ }
+ static void syntax_error_unterm_str(unsigned lineno, const char *s)
+ {
+ 	die_if_script(lineno, "syntax error: unterminated %s", s);
+ }
+ /* It so happens that all such cases are totally fatal
+  * even if shell is interactive: EOF while looking for closing
+  * delimiter. There is nowhere to read stuff from after that,
+  * it's EOF! The only choice is to terminate.
+  */
+ static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
+ static void syntax_error_unterm_ch(unsigned lineno, char ch)
+ {
+ 	char msg[2] = { ch, '\0' };
+ 	syntax_error_unterm_str(lineno, msg);
+ 	xfunc_die();
+ }
+ static void syntax_error_unexpected_ch(unsigned lineno, int ch)
+ {
+ 	char msg[2];
+ 	msg[0] = ch;
+ 	msg[1] = '\0';
+ 	die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
  }
+ #if HUSH_DEBUG < 2
+ # undef die_if_script
+ # undef syntax_error
+ # undef syntax_error_at
+ # undef syntax_error_unterm_ch
+ # undef syntax_error_unterm_str
+ # undef syntax_error_unexpected_ch
+ #else
+ # define die_if_script(...)             die_if_script(__LINE__, __VA_ARGS__)
+ # define syntax_error(msg)              syntax_error(__LINE__, msg)
+ # define syntax_error_at(msg)           syntax_error_at(__LINE__, msg)
+ # define syntax_error_unterm_ch(ch)     syntax_error_unterm_ch(__LINE__, ch)
+ # define syntax_error_unterm_str(s)     syntax_error_unterm_str(__LINE__, s)
+ # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
+ #endif
+ #if ENABLE_HUSH_INTERACTIVE
+ static void cmdedit_update_prompt(void);
+ #else
+ # define cmdedit_update_prompt() ((void)0)
+ #endif
+ /* Utility functions
+  */
  /* Replace each \x with x in place, return ptr past NUL. */
  static char *unbackslash(char *src)
  {
- 	char *dst = src;
+ 	char *dst = src = strchrnul(src, '\\');
  	while (1) {
  		if (*src == '\\')
  			src++;
-Line 664 
 static char **add_strings_to_strings(cha
+Line 938 
 static char **add_strings_to_strings(cha
  		v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
  	return v;
  }
+ #if LEAK_HUNTING
+ static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
+ {
+ 	char **ptr = add_strings_to_strings(strings, add, need_to_dup);
+ 	fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
+ 	return ptr;
+ }
+ #define add_strings_to_strings(strings, add, need_to_dup) \
+ 	xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
+ #endif
+ /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
  static char **add_string_to_strings(char **strings, char *add)
  {
  	char *v[2];
-Line 672 
 static char **add_string_to_strings(char
+Line 957 
 static char **add_string_to_strings(char
  	v[1] = NULL;
  	return add_strings_to_strings(strings, v, /*dup:*/ 0);
  }
+ #if LEAK_HUNTING
- static void putenv_all(char **strings)
+ static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
- {
- 	if (!strings)
- 		return;
- 	while (*strings) {
- 		debug_printf_env("putenv '%s'\n", *strings);
- 		putenv(*strings++);
- 	}
- }
- static char **putenv_all_and_save_old(char **strings)
  {
- 	char **old = NULL;
+ 	char **ptr = add_string_to_strings(strings, add);
- 	char **s = strings;
+ 	fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
+ 	return ptr;
- 	if (!strings)
- 		return old;
- 	while (*strings) {
- 		char *v, *eq;
- 		eq = strchr(*strings, '=');
- 		if (eq) {
- 			*eq = '\0';
- 			v = getenv(*strings);
- 			*eq = '=';
- 			if (v) {
- 				/* v points to VAL in VAR=VAL, go back to VAR */
- 				v -= (eq - *strings) + 1;
- 				old = add_string_to_strings(old, v);
- 			}
- 		}
- 		strings++;
- 	}
- 	putenv_all(s);
- 	return old;
  }
+ #define add_string_to_strings(strings, add) \
+ 	xx_add_string_to_strings(__LINE__, strings, add)
+ #endif
- static void free_strings_and_unsetenv(char **strings, int unset)
+ static void free_strings(char **strings)
  {
  	char **v;
  	if (!strings)
  		return;
  	v = strings;
  	while (*v) {
- 		if (unset) {
+ 		free(*v);
- 			char *copy;
+ 		v++;
- 			/* *strchrnul(*v, '=') = '\0'; -- BAD
- 			 * In case *v was putenv'ed, we can't
- 			 * unsetenv(*v) after taking out '=':
- 			 * it won't work, env is modified by taking out!
- 			 * horror :( */
- 			copy = xstrndup(*v, strchrnul(*v, '=') - *v);
- 			debug_printf_env("unsetenv '%s'\n", copy);
- 			unsetenv(copy);
- 			free(copy);
- 		}
- 		free(*v++);
  	}
  	free(strings);
  }
- static void free_strings(char **strings)
+ /* Helpers for setting new $n and restoring them back
+  */
+ typedef struct save_arg_t {
+ 	char *sv_argv0;
+ 	char **sv_g_argv;
+ 	int sv_g_argc;
+ 	smallint sv_g_malloced;
+ } save_arg_t;
+ static void save_and_replace_G_args(save_arg_t *sv, char **argv)
  {
- 	free_strings_and_unsetenv(strings, 0);
+ 	int n;
+ 	sv->sv_argv0 = argv[0];
+ 	sv->sv_g_argv = G.global_argv;
+ 	sv->sv_g_argc = G.global_argc;
+ 	sv->sv_g_malloced = G.global_args_malloced;
+ 	argv[0] = G.global_argv[0]; /* retain $0 */
+ 	G.global_argv = argv;
+ 	G.global_args_malloced = 0;
+ 	n = 1;
+ 	while (*++argv)
+ 		n++;
+ 	G.global_argc = n;
  }
+ static void restore_G_args(save_arg_t *sv, char **argv)
+ {
+ 	char **pp;
- /* Function prototypes for builtins */
+ 	if (G.global_args_malloced) {
- static int builtin_cd(char **argv);
+ 		/* someone ran "set -- arg1 arg2 ...", undo */
- static int builtin_echo(char **argv);
+ 		pp = G.global_argv;
- static int builtin_eval(char **argv);
+ 		while (*++pp) /* note: does not free $0 */
- static int builtin_exec(char **argv);
+ 			free(*pp);
- static int builtin_exit(char **argv);
+ 		free(G.global_argv);
- static int builtin_export(char **argv);
+ 	}
- #if ENABLE_HUSH_JOB
+ 	argv[0] = sv->sv_argv0;
- static int builtin_fg_bg(char **argv);
+ 	G.global_argv = sv->sv_g_argv;
- static int builtin_jobs(char **argv);
+ 	G.global_argc = sv->sv_g_argc;
- #endif
+ 	G.global_args_malloced = sv->sv_g_malloced;
- #if ENABLE_HUSH_HELP
+ }
- static int builtin_help(char **argv);
- #endif
- static int builtin_pwd(char **argv);
- static int builtin_read(char **argv);
- static int builtin_test(char **argv);
- static int builtin_true(char **argv);
- static int builtin_set(char **argv);
- static int builtin_shift(char **argv);
- static int builtin_source(char **argv);
- static int builtin_umask(char **argv);
- static int builtin_unset(char **argv);
- #if ENABLE_HUSH_LOOPS
- static int builtin_break(char **argv);
- static int builtin_continue(char **argv);
- #endif
- //static int builtin_not_written(char **argv);
- /* Table of built-in functions.  They can be forked or not, depending on
-  * context: within pipes, they fork.  As simple commands, they do not.
-  * When used in non-forking context, they can change global variables
-  * in the parent shell process.  If forked, of course they cannot.
-  * For example, 'unset foo | whatever' will parse and run, but foo will
-  * still be set at the end. */
- struct built_in_command {
- 	const char *cmd;
- 	int (*function)(char **argv);
- #if ENABLE_HUSH_HELP
- 	const char *descr;
- #define BLTIN(cmd, func, help) { cmd, func, help }
- #else
- #define BLTIN(cmd, func, help) { cmd, func }
- #endif
- };
- /* For now, echo and test are unconditionally enabled.
+ /* Basic theory of signal handling in shell
-  * Maybe make it configurable? */
+  * ========================================
- static const struct built_in_command bltins[] = {
+  * This does not describe what hush does, rather, it is current understanding
- 	BLTIN("."     , builtin_source, "Run commands in a file"),
+  * what it _should_ do. If it doesn't, it's a bug.
- 	BLTIN(":"     , builtin_true, "No-op"),
+  * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
- 	BLTIN("["     , builtin_test, "Test condition"),
+  *
- 	BLTIN("[["    , builtin_test, "Test condition"),
+  * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
- #if ENABLE_HUSH_JOB
+  * is finished or backgrounded. It is the same in interactive and
- 	BLTIN("bg"    , builtin_fg_bg, "Resume a job in the background"),
+  * non-interactive shells, and is the same regardless of whether
- #endif
+  * a user trap handler is installed or a shell special one is in effect.
- #if ENABLE_HUSH_LOOPS
+  * ^C or ^Z from keyboard seems to execute "at once" because it usually
- 	BLTIN("break" , builtin_break, "Exit from a loop"),
+  * backgrounds (i.e. stops) or kills all members of currently running
- #endif
+  * pipe.
- 	BLTIN("cd"    , builtin_cd, "Change directory"),
+  *
- #if ENABLE_HUSH_LOOPS
+  * Wait builtin in interruptible by signals for which user trap is set
- 	BLTIN("continue", builtin_continue, "Start new loop iteration"),
+  * or by SIGINT in interactive shell.
- #endif
+  *
- 	BLTIN("echo"  , builtin_echo, "Write to stdout"),
+  * Trap handlers will execute even within trap handlers. (right?)
- 	BLTIN("eval"  , builtin_eval, "Construct and run shell command"),
+  *
- 	BLTIN("exec"  , builtin_exec, "Execute command, don't return to shell"),
+  * User trap handlers are forgotten when subshell ("(cmd)") is entered,
- 	BLTIN("exit"  , builtin_exit, "Exit"),
+  * except for handlers set to '' (empty string).
- 	BLTIN("export", builtin_export, "Set environment variable"),
+  *
+  * If job control is off, backgrounded commands ("cmd &")
+  * have SIGINT, SIGQUIT set to SIG_IGN.
+  *
+  * Commands which are run in command substitution ("`cmd`")
+  * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
+  *
+  * Ordinary commands have signals set to SIG_IGN/DFL as inherited
+  * by the shell from its parent.
+  *
+  * Signals which differ from SIG_DFL action
+  * (note: child (i.e., [v]forked) shell is not an interactive shell):
+  *
+  * SIGQUIT: ignore
+  * SIGTERM (interactive): ignore
+  * SIGHUP (interactive):
+  *    send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
+  * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
+  *    Note that ^Z is handled not by trapping SIGTSTP, but by seeing
+  *    that all pipe members are stopped. Try this in bash:
+  *    while :; do :; done - ^Z does not background it
+  *    (while :; do :; done) - ^Z backgrounds it
+  * SIGINT (interactive): wait for last pipe, ignore the rest
+  *    of the command line, show prompt. NB: ^C does not send SIGINT
+  *    to interactive shell while shell is waiting for a pipe,
+  *    since shell is bg'ed (is not in foreground process group).
+  *    Example 1: this waits 5 sec, but does not execute ls:
+  *    "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
+  *    Example 2: this does not wait and does not execute ls:
+  *    "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
+  *    Example 3: this does not wait 5 sec, but executes ls:
+  *    "sleep 5; ls -l" + press ^C
+  *
+  * (What happens to signals which are IGN on shell start?)
+  * (What happens with signal mask on shell start?)
+  *
+  * Implementation in hush
+  * ======================
+  * We use in-kernel pending signal mask to determine which signals were sent.
+  * We block all signals which we don't want to take action immediately,
+  * i.e. we block all signals which need to have special handling as described
+  * above, and all signals which have traps set.
+  * After each pipe execution, we extract any pending signals via sigtimedwait()
+  * and act on them.
+  *
+  * unsigned non_DFL_mask: a mask of such "special" signals
+  * sigset_t blocked_set:  current blocked signal set
+  *
+  * "trap - SIGxxx":
+  *    clear bit in blocked_set unless it is also in non_DFL_mask
+  * "trap 'cmd' SIGxxx":
+  *    set bit in blocked_set (even if 'cmd' is '')
+  * after [v]fork, if we plan to be a shell:
+  *    unblock signals with special interactive handling
+  *    (child shell is not interactive),
+  *    unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
+  * after [v]fork, if we plan to exec:
+  *    POSIX says fork clears pending signal mask in child - no need to clear it.
+  *    Restore blocked signal set to one inherited by shell just prior to exec.
+  *
+  * Note: as a result, we do not use signal handlers much. The only uses
+  * are to count SIGCHLDs
+  * and to restore tty pgrp on signal-induced exit.
+  *
+  * Note 2 (compat):
+  * Standard says "When a subshell is entered, traps that are not being ignored
+  * are set to the default actions". bash interprets it so that traps which
+  * are set to '' (ignore) are NOT reset to defaults. We do the same.
+  */
+ enum {
+ 	SPECIAL_INTERACTIVE_SIGS = 0
+ 		| (1 << SIGTERM)
+ 		| (1 << SIGINT)
+ 		| (1 << SIGHUP)
+ 		,
+ 	SPECIAL_JOB_SIGS = 0
  #if ENABLE_HUSH_JOB
- 	BLTIN("fg"    , builtin_fg_bg, "Bring job into the foreground"),
+ 		| (1 << SIGTTIN)
- 	BLTIN("jobs"  , builtin_jobs, "List active jobs"),
+ 		| (1 << SIGTTOU)
- #endif
+ 		| (1 << SIGTSTP)
- 	BLTIN("pwd"   , builtin_pwd, "Print current directory"),
- 	BLTIN("read"  , builtin_read, "Input environment variable"),
- //	BLTIN("return", builtin_not_written, "Return from a function"),
- 	BLTIN("set"   , builtin_set, "Set/unset shell local variables"),
- 	BLTIN("shift" , builtin_shift, "Shift positional parameters"),
- //	BLTIN("trap"  , builtin_not_written, "Trap signals"),
- 	BLTIN("test"  , builtin_test, "Test condition"),
- //	BLTIN("ulimit", builtin_not_written, "Control resource limits"),
- 	BLTIN("umask" , builtin_umask, "Set file creation mask"),
- 	BLTIN("unset" , builtin_unset, "Unset environment variable"),
- #if ENABLE_HUSH_HELP
- 	BLTIN("help"  , builtin_help, "List shell built-in commands"),
  #endif
  };
+ #if ENABLE_HUSH_FAST
- /* Signals are grouped, we handle them in batches */
+ static void SIGCHLD_handler(int sig UNUSED_PARAM)
- static void set_misc_sighandler(void (*handler)(int))
  {
- 	bb_signals(0
+ 	G.count_SIGCHLD++;
- 		+ (1 << SIGINT)
+ //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
- 		+ (1 << SIGQUIT)
- 		+ (1 << SIGTERM)
- 		, handler);
  }
+ #endif
  #if ENABLE_HUSH_JOB
- static void set_fatal_sighandler(void (*handler)(int))
+ /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
- {
+ #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
- 	bb_signals(0
+ /* After [v]fork, in parent: restore tty pgrp on xfunc death */
- 		+ (1 << SIGILL)
+ #define enable_restore_tty_pgrp_on_exit()  (die_sleep = -1)
- 		+ (1 << SIGTRAP)
- 		+ (1 << SIGABRT)
- 		+ (1 << SIGFPE)
- 		+ (1 << SIGBUS)
- 		+ (1 << SIGSEGV)
- 	/* bash 3.2 seems to handle these just like 'fatal' ones */
- 		+ (1 << SIGHUP)
- 		+ (1 << SIGPIPE)
- 		+ (1 << SIGALRM)
- 		, handler);
- }
- static void set_jobctrl_sighandler(void (*handler)(int))
- {
- 	bb_signals(0
- 		+ (1 << SIGTSTP)
- 		+ (1 << SIGTTIN)
- 		+ (1 << SIGTTOU)
- 		, handler);
- }
- /* SIGCHLD is special and handled separately */
- static void set_every_sighandler(void (*handler)(int))
- {
- 	set_fatal_sighandler(handler);
- 	set_jobctrl_sighandler(handler);
- 	set_misc_sighandler(handler);
- 	signal(SIGCHLD, handler);
- }
- static void handler_ctrl_c(int sig UNUSED_PARAM)
- {
- 	debug_printf_jobs("got sig %d\n", sig);
- // as usual we can have all kinds of nasty problems with leaked malloc data here
- 	siglongjmp(G.toplevel_jb, 1);
- }
- static void handler_ctrl_z(int sig UNUSED_PARAM)
- {
- 	pid_t pid;
- 	debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
- 	pid = fork();
- 	if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
- 		return;
- 	G.ctrl_z_flag = 1;
- 	if (!pid) { /* child */
- 		if (ENABLE_HUSH_JOB)
- 			die_sleep = 0; /* let nofork's xfuncs die */
- 		bb_setpgrp();
- 		debug_printf_jobs("set pgrp for child %d ok\n", getpid());
- 		set_every_sighandler(SIG_DFL);
- 		raise(SIGTSTP); /* resend TSTP so that child will be stopped */
- 		debug_printf_jobs("returning in child\n");
- 		/* return to nofork, it will eventually exit now,
- 		 * not return back to shell */
- 		return;
- 	}
- 	/* parent */
- 	/* finish filling up pipe info */
- 	G.toplevel_list->pgrp = pid; /* child is in its own pgrp */
- 	G.toplevel_list->cmds[0].pid = pid;
- 	/* parent needs to longjmp out of running nofork.
- 	 * we will "return" exitcode 0, with child put in background */
- // as usual we can have all kinds of nasty problems with leaked malloc data here
- 	debug_printf_jobs("siglongjmp in parent\n");
- 	siglongjmp(G.toplevel_jb, 1);
- }
  /* Restores tty foreground process group, and exits.
   * May be called as signal handler for fatal signal
-  * (will faithfully resend signal to itself, producing correct exit state)
+  * (will resend signal to itself, producing correct exit state)
   * or called directly with -EXITCODE.
   * We also call it if xfunc is exiting. */
  static void sigexit(int sig) NORETURN;
-Line 925 
 static void sigexit(int sig)
+Line 1159 
 static void sigexit(int sig)
  	/* Disable all signals: job control, SIGPIPE, etc. */
  	sigprocmask_allsigs(SIG_BLOCK);
- #if ENABLE_HUSH_INTERACTIVE
+ 	/* Careful: we can end up here after [v]fork. Do not restore
- 	if (G.interactive_fd)
+ 	 * tty pgrp then, only top-level shell process does that */
- 		tcsetpgrp(G.interactive_fd, G.saved_tty_pgrp);
+ 	if (G_saved_tty_pgrp && getpid() == G.root_pid)
- #endif
+ 		tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
  	/* Not a signal, just exit */
  	if (sig <= 0)
-Line 936 
 static void sigexit(int sig)
+Line 1170 
 static void sigexit(int sig)
  	kill_myself_with_sig(sig); /* does not return */
  }
+ #else
+ #define disable_restore_tty_pgrp_on_exit() ((void)0)
+ #define enable_restore_tty_pgrp_on_exit()  ((void)0)
+ #endif
  /* Restores tty foreground process group, and exits. */
  static void hush_exit(int exitcode) NORETURN;
  static void hush_exit(int exitcode)
  {
- 	fflush(NULL); /* flush all streams */
+ 	if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
+ 		/* Prevent recursion:
+ 		 * trap "echo Hi; exit" EXIT; exit
+ 		 */
+ 		char *argv[] = { NULL, G.traps[0], NULL };
+ 		G.traps[0] = NULL;
+ 		G.exiting = 1;
+ 		builtin_eval(argv);
+ 		free(argv[1]);
+ 	}
+ #if ENABLE_HUSH_JOB
+ 	fflush_all();
  	sigexit(- (exitcode & 0xff));
+ #else
+ 	exit(exitcode);
+ #endif
  }
- #else /* !JOB */
+ static int check_and_run_traps(int sig)
+ {
- #define set_fatal_sighandler(handler)   ((void)0)
+ 	static const struct timespec zero_timespec = { 0, 0 };
- #define set_jobctrl_sighandler(handler) ((void)0)
+ 	smalluint save_rcode;
- #define hush_exit(e)                    exit(e)
+ 	int last_sig = 0;
- #endif /* JOB */
+ 	if (sig)
+ 		goto jump_in;
+ 	while (1) {
+ 		sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
+ 		if (sig <= 0)
+ 			break;
+  jump_in:
+ 		last_sig = sig;
+ 		if (G.traps && G.traps[sig]) {
+ 			if (G.traps[sig][0]) {
+ 				/* We have user-defined handler */
+ 				char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
+ 				save_rcode = G.last_exitcode;
+ 				builtin_eval(argv);
+ 				free(argv[1]);
+ 				G.last_exitcode = save_rcode;
+ 			} /* else: "" trap, ignoring signal */
+ 			continue;
+ 		}
+ 		/* not a trap: special action */
+ 		switch (sig) {
+ #if ENABLE_HUSH_FAST
+ 		case SIGCHLD:
+ 			G.count_SIGCHLD++;
+ //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
+ 			break;
+ #endif
+ 		case SIGINT:
+ 			/* Builtin was ^C'ed, make it look prettier: */
+ 			bb_putchar('\n');
+ 			G.flag_SIGINT = 1;
+ 			break;
+ #if ENABLE_HUSH_JOB
+ 		case SIGHUP: {
+ 			struct pipe *job;
+ 			/* bash is observed to signal whole process groups,
+ 			 * not individual processes */
+ 			for (job = G.job_list; job; job = job->next) {
+ 				if (job->pgrp <= 0)
+ 					continue;
+ 				debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
+ 				if (kill(- job->pgrp, SIGHUP) == 0)
+ 					kill(- job->pgrp, SIGCONT);
+ 			}
+ 			sigexit(SIGHUP);
+ 		}
+ #endif
+ 		default: /* ignored: */
+ 			/* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
+ 			break;
+ 		}
+ 	}
+ 	return last_sig;
+ }
- static const char *set_cwd(void)
+ static const char *get_cwd(int force)
  {
- 	if (G.cwd == bb_msg_unknown)
+ 	if (force || G.cwd == NULL) {
- 		G.cwd = NULL;     /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
+ 		/* xrealloc_getcwd_or_warn(arg) calls free(arg),
- 	G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
+ 		 * we must not try to free(bb_msg_unknown) */
- 	if (!G.cwd)
+ 		if (G.cwd == bb_msg_unknown)
- 		G.cwd = bb_msg_unknown;
+ 			G.cwd = NULL;
+ 		G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
+ 		if (!G.cwd)
+ 			G.cwd = bb_msg_unknown;
+ 	}
  	return G.cwd;
  }
  /*
-  * o_string support
+  * Shell and environment variable support
   */
- #define B_CHUNK  (32 * sizeof(char*))
+ static struct variable **get_ptr_to_local_var(const char *name)
- static void o_reset(o_string *o)
  {
- 	o->length = 0;
+ 	struct variable **pp;
- 	o->nonnull = 0;
+ 	struct variable *cur;
- 	if (o->data)
+ 	int len;
- 		o->data[0] = '\0';
+ 	len = strlen(name);
+ 	pp = &G.top_var;
+ 	while ((cur = *pp) != NULL) {
+ 		if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
+ 			return pp;
+ 		pp = &cur->next;
+ 	}
+ 	return NULL;
  }
- static void o_free(o_string *o)
+ static struct variable *get_local_var(const char *name)
  {
- 	free(o->data);
+ 	struct variable **pp = get_ptr_to_local_var(name);
- 	memset(o, 0, sizeof(*o));
+ 	if (pp)
+ 		return *pp;
+ 	return NULL;
  }
- static void o_grow_by(o_string *o, int len)
+ static const char* FAST_FUNC get_local_var_value(const char *name)
  {
- 	if (o->length + len > o->maxlen) {
+ 	struct variable **pp = get_ptr_to_local_var(name);
- 		o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
+ 	if (pp)
- 		o->data = xrealloc(o->data, 1 + o->maxlen);
+ 		return strchr((*pp)->varstr, '=') + 1;
+ 	if (strcmp(name, "PPID") == 0)
+ 		return utoa(G.root_ppid);
+ 	// bash compat: UID? EUID?
+ #if ENABLE_HUSH_RANDOM_SUPPORT
+ 	if (strcmp(name, "RANDOM") == 0) {
+ 		return utoa(next_random(&G.random_gen));
  	}
+ #endif
+ 	return NULL;
  }
- static void o_addchr(o_string *o, int ch)
+ /* str holds "NAME=VAL" and is expected to be malloced.
+  * We take ownership of it.
+  * flg_export:
+  *  0: do not change export flag
+  *     (if creating new variable, flag will be 0)
+  *  1: set export flag and putenv the variable
+  * -1: clear export flag and unsetenv the variable
+  * flg_read_only is set only when we handle -R var=val
+  */
+ #if !BB_MMU && ENABLE_HUSH_LOCAL
+ /* all params are used */
+ #elif BB_MMU && ENABLE_HUSH_LOCAL
+ #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
+ 	set_local_var(str, flg_export, local_lvl)
+ #elif BB_MMU && !ENABLE_HUSH_LOCAL
+ #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
+ 	set_local_var(str, flg_export)
+ #elif !BB_MMU && !ENABLE_HUSH_LOCAL
+ #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
+ 	set_local_var(str, flg_export, flg_read_only)
+ #endif
+ static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
  {
- 	debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
+ 	struct variable **var_pp;
- 	o_grow_by(o, 1);
+ 	struct variable *cur;
- 	o->data[o->length] = ch;
+ 	char *eq_sign;
- 	o->length++;
+ 	int name_len;
- 	o->data[o->length] = '\0';
+ 	eq_sign = strchr(str, '=');
+ 	if (!eq_sign) { /* not expected to ever happen? */
+ 		free(str);
+ 		return -1;
+ 	}
+ 	name_len = eq_sign - str + 1; /* including '=' */
+ 	var_pp = &G.top_var;
+ 	while ((cur = *var_pp) != NULL) {
+ 		if (strncmp(cur->varstr, str, name_len) != 0) {
+ 			var_pp = &cur->next;
+ 			continue;
+ 		}
+ 		/* We found an existing var with this name */
+ 		if (cur->flg_read_only) {
+ #if !BB_MMU
+ 			if (!flg_read_only)
+ #endif
+ 				bb_error_msg("%s: readonly variable", str);
+ 			free(str);
+ 			return -1;
+ 		}
+ 		if (flg_export == -1) { // "&& cur->flg_export" ?
+ 			debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
+ 			*eq_sign = '\0';
+ 			unsetenv(str);
+ 			*eq_sign = '=';
+ 		}
+ #if ENABLE_HUSH_LOCAL
+ 		if (cur->func_nest_level < local_lvl) {
+ 			/* New variable is declared as local,
+ 			 * and existing one is global, or local
+ 			 * from enclosing function.
+ 			 * Remove and save old one: */
+ 			*var_pp = cur->next;
+ 			cur->next = *G.shadowed_vars_pp;
+ 			*G.shadowed_vars_pp = cur;
+ 			/* bash 3.2.33(1) and exported vars:
+ 			 * # export z=z
+ 			 * # f() { local z=a; env | grep ^z; }
+ 			 * # f
+ 			 * z=a
+ 			 * # env | grep ^z
+ 			 * z=z
+ 			 */
+ 			if (cur->flg_export)
+ 				flg_export = 1;
+ 			break;
+ 		}
+ #endif
+ 		if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
+  free_and_exp:
+ 			free(str);
+ 			goto exp;
+ 		}
+ 		if (cur->max_len != 0) {
+ 			if (cur->max_len >= strlen(str)) {
+ 				/* This one is from startup env, reuse space */
+ 				strcpy(cur->varstr, str);
+ 				goto free_and_exp;
+ 			}
+ 		} else {
+ 			/* max_len == 0 signifies "malloced" var, which we can
+ 			 * (and has to) free */
+ 			free(cur->varstr);
+ 		}
+ 		cur->max_len = 0;
+ 		goto set_str_and_exp;
+ 	}
+ 	/* Not found - create new variable struct */
+ 	cur = xzalloc(sizeof(*cur));
+ #if ENABLE_HUSH_LOCAL
+ 	cur->func_nest_level = local_lvl;
+ #endif
+ 	cur->next = *var_pp;
+ 	*var_pp = cur;
+  set_str_and_exp:
+ 	cur->varstr = str;
+ #if !BB_MMU
+ 	cur->flg_read_only = flg_read_only;
+ #endif
+  exp:
+ 	if (flg_export == 1)
+ 		cur->flg_export = 1;
+ 	if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
+ 		cmdedit_update_prompt();
+ 	if (cur->flg_export) {
+ 		if (flg_export == -1) {
+ 			cur->flg_export = 0;
+ 			/* unsetenv was already done */
+ 		} else {
+ 			debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
+ 			return putenv(cur->varstr);
+ 		}
+ 	}
+ 	return 0;
  }
- static void o_addstr(o_string *o, const char *str, int len)
+ /* Used at startup and after each cd */
+ static void set_pwd_var(int exp)
  {
- 	o_grow_by(o, len);
+ 	set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
- 	memcpy(&o->data[o->length], str, len);
+ 		/*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
- 	o->length += len;
- 	o->data[o->length] = '\0';
  }
- static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
+ static int unset_local_var_len(const char *name, int name_len)
  {
- 	while (len) {
+ 	struct variable *cur;
- 		o_addchr(o, *str);
+ 	struct variable **var_pp;
- 		if (*str++ == '\\'
- 		 && (*str != '*' && *str != '?' && *str != '[')
+ 	if (!name)
- 		) {
+ 		return EXIT_SUCCESS;
- 			o_addchr(o, '\\');
+ 	var_pp = &G.top_var;
+ 	while ((cur = *var_pp) != NULL) {
+ 		if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
+ 			if (cur->flg_read_only) {
+ 				bb_error_msg("%s: readonly variable", name);
+ 				return EXIT_FAILURE;
+ 			}
+ 			*var_pp = cur->next;
+ 			debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
+ 			bb_unsetenv(cur->varstr);
+ 			if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
+ 				cmdedit_update_prompt();
+ 			if (!cur->max_len)
+ 				free(cur->varstr);
+ 			free(cur);
+ 			return EXIT_SUCCESS;
  		}
- 		len--;
+ 		var_pp = &cur->next;
  	}
+ 	return EXIT_SUCCESS;
  }
- /* My analysis of quoting semantics tells me that state information
+ static int unset_local_var(const char *name)
-  * is associated with a destination, not a source.
-  */
- static void o_addqchr(o_string *o, int ch)
  {
- 	int sz = 1;
+ 	return unset_local_var_len(name, strlen(name));
- 	char *found = strchr("*?[\\", ch);
- 	if (found)
- 		sz++;
- 	o_grow_by(o, sz);
- 	if (found) {
- 		o->data[o->length] = '\\';
- 		o->length++;
- 	}
- 	o->data[o->length] = ch;
- 	o->length++;
- 	o->data[o->length] = '\0';
  }
- static void o_addQchr(o_string *o, int ch)
+ static void unset_vars(char **strings)
  {
- 	int sz = 1;
+ 	char **v;
- 	if (o->o_quote && strchr("*?[\\", ch)) {
- 		sz++;
+ 	if (!strings)
- 		o->data[o->length] = '\\';
+ 		return;
- 		o->length++;
+ 	v = strings;
+ 	while (*v) {
+ 		const char *eq = strchrnul(*v, '=');
+ 		unset_local_var_len(*v, (int)(eq - *v));
+ 		v++;
  	}
- 	o_grow_by(o, sz);
+ 	free(strings);
- 	o->data[o->length] = ch;
- 	o->length++;
- 	o->data[o->length] = '\0';
  }
- static void o_addQstr(o_string *o, const char *str, int len)
+ #if ENABLE_SH_MATH_SUPPORT
+ #define is_name(c)      ((c) == '_' || isalpha((unsigned char)(c)))
+ #define is_in_name(c)   ((c) == '_' || isalnum((unsigned char)(c)))
+ static char* FAST_FUNC endofname(const char *name)
  {
- 	if (!o->o_quote) {
+ 	char *p;
- 		o_addstr(o, str, len);
- 		return;
- 	}
- 	while (len) {
- 		char ch;
- 		int sz;
- 		int ordinary_cnt = strcspn(str, "*?[\\");
- 		if (ordinary_cnt > len) /* paranoia */
- 			ordinary_cnt = len;
- 		o_addstr(o, str, ordinary_cnt);
- 		if (ordinary_cnt == len)
- 			return;
- 		str += ordinary_cnt;
- 		len -= ordinary_cnt + 1; /* we are processing + 1 char below */
- 		ch = *str++;
+ 	p = (char *) name;
- 		sz = 1;
+ 	if (!is_name(*p))
- 		if (ch) { /* it is necessarily one of "*?[\\" */
+ 		return p;
- 			sz++;
+ 	while (*++p) {
- 			o->data[o->length] = '\\';
+ 		if (!is_in_name(*p))
- 			o->length++;
+ 			break;
- 		}
- 		o_grow_by(o, sz);
- 		o->data[o->length] = ch;
- 		o->length++;
- 		o->data[o->length] = '\0';
  	}
+ 	return p;
  }
+ #endif
- /* A special kind of o_string for $VAR and `cmd` expansion.
+ static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
-  * It contains char* list[] at the beginning, which is grown in 16 element
+ {
-  * increments. Actual string data starts at the next multiple of 16 * (char*).
+ 	char *var = xasprintf("%s=%s", name, val);
-  * list[i] contains an INDEX (int!) into this string data.
+ 	set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
-  * It means that if list[] needs to grow, data needs to be moved higher up
+ }
-  * but list[i]'s need not be modified.
-  * NB: remembering how many list[i]'s you have there is crucial.
-  * o_finalize_list() operation post-processes this structure - calculates
+ /*
-  * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
+  * Helpers for "var1=val1 var2=val2 cmd" feature
   */
- #if DEBUG_EXPAND || DEBUG_GLOB
+ static void add_vars(struct variable *var)
- static void debug_print_list(const char *prefix, o_string *o, int n)
  {
- 	char **list = (char**)o->data;
+ 	struct variable *next;
- 	int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
- 	int i = 0;
+ 	while (var) {
- 	fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
+ 		next = var->next;
- 			prefix, list, n, string_start, o->length, o->maxlen);
+ 		var->next = G.top_var;
- 	while (i < n) {
+ 		G.top_var = var;
- 		fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
+ 		if (var->flg_export) {
- 				o->data + (int)list[i] + string_start,
+ 			debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
- 				o->data + (int)list[i] + string_start);
+ 			putenv(var->varstr);
- 		i++;
+ 		} else {
- 	}
+ 			debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
- 	if (n) {
+ 		}
- 		const char *p = o->data + (int)list[n - 1] + string_start;
+ 		var = next;
- 		fprintf(stderr, " total_sz:%d\n", (p + strlen(p) + 1) - o->data);
  	}
  }
- #else
- #define debug_print_list(prefix, o, n) ((void)0)
- #endif
- /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
+ static struct variable *set_vars_and_save_old(char **strings)
-  * in list[n] so that it points past last stored byte so far.
-  * It returns n+1. */
- static int o_save_ptr_helper(o_string *o, int n)
  {
- 	char **list = (char**)o->data;
+ 	char **s;
- 	int string_start;
+ 	struct variable *old = NULL;
- 	int string_len;
- 	if (!o->has_empty_slot) {
+ 	if (!strings)
- 		string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
+ 		return old;
- 		string_len = o->length - string_start;
+ 	s = strings;
- 		if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
+ 	while (*s) {
- 			debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
+ 		struct variable *var_p;
- 			/* list[n] points to string_start, make space for 16 more pointers */
+ 		struct variable **var_pp;
- 			o->maxlen += 0x10 * sizeof(list[0]);
+ 		char *eq;
- 			o->data = xrealloc(o->data, o->maxlen + 1);
- 			list = (char**)o->data;
- 			memmove(list + n + 0x10, list + n, string_len);
- 			o->length += 0x10 * sizeof(list[0]);
- 		} else
- 			debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
- 	} else {
- 		/* We have empty slot at list[n], reuse without growth */
- 		string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
- 		string_len = o->length - string_start;
- 		debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
- 		o->has_empty_slot = 0;
- 	}
- 	list[n] = (char*)(ptrdiff_t)string_len;
- 	return n + 1;
- }
- /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
- static int o_get_last_ptr(o_string *o, int n)
- {
- 	char **list = (char**)o->data;
- 	int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
- 	return ((int)(ptrdiff_t)list[n-1]) + string_start;
- }
- /* o_glob performs globbing on last list[], saving each result
-  * as a new list[]. */
- static int o_glob(o_string *o, int n)
- {
- 	glob_t globdata;
- 	int gr;
- 	char *pattern;
- 	debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
- 	if (!o->data)
- 		return o_save_ptr_helper(o, n);
- 	pattern = o->data + o_get_last_ptr(o, n);
- 	debug_printf_glob("glob pattern '%s'\n", pattern);
- 	if (!glob_needed(pattern)) {
-  literal:
- 		o->length = unbackslash(pattern) - o->data;
- 		debug_printf_glob("glob pattern '%s' is literal\n", pattern);
- 		return o_save_ptr_helper(o, n);
- 	}
- 	memset(&globdata, 0, sizeof(globdata));
+ 		eq = strchr(*s, '=');
- 	gr = glob(pattern, 0, NULL, &globdata);
+ 		if (eq) {
- 	debug_printf_glob("glob('%s'):%d\n", pattern, gr);
+ 			*eq = '\0';
- 	if (gr == GLOB_NOSPACE)
+ 			var_pp = get_ptr_to_local_var(*s);
- 		bb_error_msg_and_die("out of memory during glob");
+ 			*eq = '=';
- 	if (gr == GLOB_NOMATCH) {
+ 			if (var_pp) {
- 		globfree(&globdata);
+ 				/* Remove variable from global linked list */
- 		goto literal;
+ 				var_p = *var_pp;
- 	}
+ 				debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
- 	if (gr != 0) { /* GLOB_ABORTED ? */
+ 				*var_pp = var_p->next;
- //TODO: testcase for bad glob pattern behavior
+ 				/* Add it to returned list */
- 		bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
+ 				var_p->next = old;
- 	}
+ 				old = var_p;
- 	if (globdata.gl_pathv && globdata.gl_pathv[0]) {
+ 			}
- 		char **argv = globdata.gl_pathv;
+ 			set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
- 		o->length = pattern - o->data; /* "forget" pattern */
- 		while (1) {
- 			o_addstr(o, *argv, strlen(*argv) + 1);
- 			n = o_save_ptr_helper(o, n);
- 			argv++;
- 			if (!*argv)
- 				break;
  		}
+ 		s++;
  	}
- 	globfree(&globdata);
+ 	return old;
- 	if (DEBUG_GLOB)
- 		debug_print_list("o_glob returning", o, n);
- 	return n;
- }
- /* If o->o_glob == 1, glob the string so far remembered.
-  * Otherwise, just finish current list[] and start new */
- static int o_save_ptr(o_string *o, int n)
- {
- 	if (o->o_glob) { /* if globbing is requested */
- 		/* If o->has_empty_slot, list[n] was already globbed
- 		 * (if it was requested back then when it was filled)
- 		 * so don't do that again! */
- 		if (!o->has_empty_slot)
- 			return o_glob(o, n); /* o_save_ptr_helper is inside */
- 	}
- 	return o_save_ptr_helper(o, n);
- }
- /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
- static char **o_finalize_list(o_string *o, int n)
- {
- 	char **list;
- 	int string_start;
- 	n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
- 	if (DEBUG_EXPAND)
- 		debug_print_list("finalized", o, n);
- 	debug_printf_expand("finalized n:%d\n", n);
- 	list = (char**)o->data;
- 	string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
- 	list[--n] = NULL;
- 	while (n) {
- 		n--;
- 		list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
- 	}
- 	return list;
  }
  /*
   * in_str support
   */
- static int static_get(struct in_str *i)
+ static int FAST_FUNC static_get(struct in_str *i)
  {
  	int ch = *i->p++;
- 	if (ch == '\0') return EOF;
+ 	if (ch != '\0')
- 	return ch;
+ 		return ch;
+ 	i->p--;
+ 	return EOF;
  }
- static int static_peek(struct in_str *i)
+ static int FAST_FUNC static_peek(struct in_str *i)
  {
  	return *i->p;
  }
  #if ENABLE_HUSH_INTERACTIVE
- #if ENABLE_FEATURE_EDITING
+ static void cmdedit_update_prompt(void)
- static void cmdedit_set_initial_prompt(void)
  {
- #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
+ 	if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
- 	G.PS1 = NULL;
+ 		G.PS1 = get_local_var_value("PS1");
- #else
+ 		if (G.PS1 == NULL)
- 	G.PS1 = getenv("PS1");
+ 			G.PS1 = "\\w \\$ ";
- 	if (G.PS1 == NULL)
+ 		G.PS2 = get_local_var_value("PS2");
- 		G.PS1 = "\\w \\$ ";
+ 	} else {
- #endif
+ 		G.PS1 = NULL;
+ 	}
+ 	if (G.PS2 == NULL)
+ 		G.PS2 = "> ";
  }
- #endif /* EDITING */
  static const char* setup_prompt_string(int promptmode)
  {
  	const char *prompt_str;
  	debug_printf("setup_prompt_string %d ", promptmode);
- #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
+ 	if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
- 	/* Set up the prompt */
+ 		/* Set up the prompt */
- 	if (promptmode == 0) { /* PS1 */
+ 		if (promptmode == 0) { /* PS1 */
- 		free((char*)G.PS1);
+ 			free((char*)G.PS1);
- 		G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
+ 			/* bash uses $PWD value, even if it is set by user.
- 		prompt_str = G.PS1;
+ 			 * It uses current dir only if PWD is unset.
- 	} else {
+ 			 * We always use current dir. */
- 		prompt_str = G.PS2;
+ 			G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
- 	}
+ 			prompt_str = G.PS1;
- #else
+ 		} else
- 	prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
+ 			prompt_str = G.PS2;
- #endif
+ 	} else
+ 		prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
  	debug_printf("result '%s'\n", prompt_str);
  	return prompt_str;
  }
-Line 1307 
 static void get_user_input(struct in_str
+Line 1649 
 static void get_user_input(struct in_str
  	/* Enable command line editing only while a command line
  	 * is actually being read */
  	do {
- 		r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
+ 		G.flag_SIGINT = 0;
- 	} while (r == 0); /* repeat if Ctrl-C */
+ 		/* buglet: SIGINT will not make new prompt to appear _at once_,
+ 		 * only after <Enter>. (^C will work) */
+ 		r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
+ 		/* catch *SIGINT* etc (^C is handled by read_line_input) */
+ 		check_and_run_traps(0);
+ 	} while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
  	i->eof_flag = (r < 0);
  	if (i->eof_flag) { /* EOF/error detected */
  		G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
  		G.user_input_buf[1] = '\0';
  	}
  #else
- 	fputs(prompt_str, stdout);
+ 	do {
- 	fflush(stdout);
+ 		G.flag_SIGINT = 0;
- 	G.user_input_buf[0] = r = fgetc(i->file);
+ 		fputs(prompt_str, stdout);
- 	/*G.user_input_buf[1] = '\0'; - already is and never changed */
+ 		fflush_all();
+ 		G.user_input_buf[0] = r = fgetc(i->file);
+ 		/*G.user_input_buf[1] = '\0'; - already is and never changed */
+ //do we need check_and_run_traps(0)? (maybe only if stdin)
+ 	} while (G.flag_SIGINT);
  	i->eof_flag = (r == EOF);
  #endif
  	i->p = G.user_input_buf;
-Line 1328 
 static void get_user_input(struct in_str
+Line 1679 
 static void get_user_input(struct in_str
  /* This is the magic location that prints prompts
   * and gets data back from the user */
- static int file_get(struct in_str *i)
+ static int FAST_FUNC file_get(struct in_str *i)
  {
  	int ch;
-Line 1340 
 static int file_get(struct in_str *i)
+Line 1691 
 static int file_get(struct in_str *i)
  		ch = *i->p++;
  		if (i->eof_flag && !*i->p)
  			ch = EOF;
+ 		/* note: ch is never NUL */
  	} else {
  		/* need to double check i->file because we might be doing something
  		 * more complicated by now, like sourcing or substituting. */
  #if ENABLE_HUSH_INTERACTIVE
- 		if (G.interactive_fd && i->promptme && i->file == stdin) {
+ 		if (G_interactive_fd && i->promptme && i->file == stdin) {
  			do {
  				get_user_input(i);
  			} while (!*i->p); /* need non-empty line */
-Line 1353 
 static int file_get(struct in_str *i)
+Line 1705 
 static int file_get(struct in_str *i)
  			goto take_cached;
  		}
  #endif
- 		ch = fgetc(i->file);
+ 		do ch = fgetc(i->file); while (ch == '\0');
  	}
- 	debug_printf("file_get: got a '%c' %d\n", ch, ch);
+ 	debug_printf("file_get: got '%c' %d\n", ch, ch);
  #if ENABLE_HUSH_INTERACTIVE
  	if (ch == '\n')
  		i->promptme = 1;
-Line 1363 
 static int file_get(struct in_str *i)
+Line 1715 
 static int file_get(struct in_str *i)
  	return ch;
  }
- /* All the callers guarantee this routine will never be
+ /* All callers guarantee this routine will never
-  * used right after a newline, so prompting is not needed.
+  * be used right after a newline, so prompting is not needed.
   */
- static int file_peek(struct in_str *i)
+ static int FAST_FUNC file_peek(struct in_str *i)
  {
  	int ch;
  	if (i->p && *i->p) {
  		if (i->eof_flag && !i->p[1])
  			return EOF;
  		return *i->p;
+ 		/* note: ch is never NUL */
  	}
- 	ch = fgetc(i->file);
+ 	do ch = fgetc(i->file); while (ch == '\0');
  	i->eof_flag = (ch == EOF);
  	i->peek_buf[0] = ch;
  	i->peek_buf[1] = '\0';
  	i->p = i->peek_buf;
- 	debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
+ 	debug_printf("file_peek: got '%c' %d\n", ch, ch);
  	return ch;
  }
-Line 1408 
 static void setup_string_in_str(struct i
+Line 1761 
 static void setup_string_in_str(struct i
  }
- /* squirrel != NULL means we squirrel away copies of stdin, stdout,
+ /*
-  * and stderr if they are redirected. */
+  * o_string support
- static int setup_redirects(struct command *prog, int squirrel[])
+  */
- {
+ #define B_CHUNK  (32 * sizeof(char*))
- 	int openfd, mode;
- 	struct redir_struct *redir;
- 	for (redir = prog->redirects; redir; redir = redir->next) {
+ static void o_reset_to_empty_unquoted(o_string *o)
- 		if (redir->dup == -1 && redir->rd_filename == NULL) {
+ {
- 			/* something went wrong in the parse.  Pretend it didn't happen */
+ 	o->length = 0;
- 			continue;
+ 	o->o_quoted = 0;
- 		}
+ 	if (o->data)
- 		if (redir->dup == -1) {
+ 		o->data[0] = '\0';
- 			char *p;
+ }
- 			mode = redir_table[redir->rd_type].mode;
- //TODO: check redir for names like '\\'
- 			p = expand_string_to_string(redir->rd_filename);
- 			openfd = open_or_warn(p, mode);
- 			free(p);
- 			if (openfd < 0) {
- 			/* this could get lost if stderr has been redirected, but
- 			   bash and ash both lose it as well (though zsh doesn't!) */
- 				return 1;
- 			}
- 		} else {
- 			openfd = redir->dup;
- 		}
- 		if (openfd != redir->fd) {
+ static void o_free(o_string *o)
- 			if (squirrel && redir->fd < 3) {
+ {
- 				squirrel[redir->fd] = dup(redir->fd);
+ 	free(o->data);
- 			}
+ 	memset(o, 0, sizeof(*o));
- 			if (openfd == -3) {
- 				//close(openfd); // close(-3) ??!
- 			} else {
- 				dup2(openfd, redir->fd);
- 				if (redir->dup == -1)
- 					close(openfd);
- 			}
- 		}
- 	}
- 	return 0;
  }
- static void restore_redirects(int squirrel[])
+ static ALWAYS_INLINE void o_free_unsafe(o_string *o)
  {
- 	int i, fd;
+ 	free(o->data);
- 	for (i = 0; i < 3; i++) {
- 		fd = squirrel[i];
- 		if (fd != -1) {
- 			/* We simply die on error */
- 			xmove_fd(fd, i);
- 		}
- 	}
  }
- static char **expand_assignments(char **argv, int count)
+ static void o_grow_by(o_string *o, int len)
  {
- 	int i;
+ 	if (o->length + len > o->maxlen) {
- 	char **p = NULL;
+ 		o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
- 	/* Expand assignments into one string each */
+ 		o->data = xrealloc(o->data, 1 + o->maxlen);
- 	for (i = 0; i < count; i++) {
- 		p = add_string_to_strings(p, expand_string_to_string(argv[i]));
  	}
- 	return p;
  }
- /* Called after [v]fork() in run_pipe(), or from builtin_exec().
+ static void o_addchr(o_string *o, int ch)
-  * Never returns.
-  * XXX no exit() here.  If you don't exec, use _exit instead.
-  * The at_exit handlers apparently confuse the calling process,
-  * in particular stdin handling.  Not sure why? -- because of vfork! (vda) */
- static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded)
  {
- 	int rcode;
+ 	debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
- 	char **new_env;
+ 	o_grow_by(o, 1);
- 	const struct built_in_command *x;
+ 	o->data[o->length] = ch;
+ 	o->length++;
+ 	o->data[o->length] = '\0';
+ }
- 	/* If a variable is assigned in a forest, and nobody listens,
+ static void o_addblock(o_string *o, const char *str, int len)
- 	 * was it ever really set?
+ {
- 	 */
+ 	o_grow_by(o, len);
- 	if (!argv[assignment_cnt])
+ 	memcpy(&o->data[o->length], str, len);
- 		_exit(EXIT_SUCCESS);
+ 	o->length += len;
+ 	o->data[o->length] = '\0';
+ }
- 	new_env = expand_assignments(argv, assignment_cnt);
- #if BB_MMU
- 	putenv_all(new_env);
- 	free(new_env); /* optional */
- #else
- 	nommu_save->new_env = new_env;
- 	nommu_save->old_env = putenv_all_and_save_old(new_env);
- #endif
- 	if (argv_expanded) {
- 		argv = argv_expanded;
- 	} else {
- 		argv = expand_strvec_to_strvec(argv);
  #if !BB_MMU
- 		nommu_save->argv = argv;
+ static void o_addstr(o_string *o, const char *str)
+ {
+ 	o_addblock(o, str, strlen(str));
+ }
+ static void nommu_addchr(o_string *o, int ch)
+ {
+ 	if (o)
+ 		o_addchr(o, ch);
+ }
+ #else
+ # define nommu_addchr(o, str) ((void)0)
  #endif
- 	}
- 	/*
+ static void o_addstr_with_NUL(o_string *o, const char *str)
- 	 * Check if the command matches any of the builtins.
+ {
- 	 * Depending on context, this might be redundant.  But it's
+ 	o_addblock(o, str, strlen(str) + 1);
- 	 * easier to waste a few CPU cycles than it is to figure out
+ }
- 	 * if this is one of those cases.
- 	 */
- 	for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
- 		if (strcmp(argv[0], x->cmd) == 0) {
- 			debug_printf_exec("running builtin '%s'\n", argv[0]);
- 			rcode = x->function(argv);
- 			fflush(stdout);
- 			_exit(rcode);
- 		}
- 	}
- 	/* Check if the command matches any busybox applets */
+ static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
- #if ENABLE_FEATURE_SH_STANDALONE
+ {
- 	if (strchr(argv[0], '/') == NULL) {
+ 	while (len) {
- 		int a = find_applet_by_name(argv[0]);
+ 		o_addchr(o, *str);
- 		if (a >= 0) {
+ 		if (*str++ == '\\'
- 			if (APPLET_IS_NOEXEC(a)) {
+ 		 && (*str != '*' && *str != '?' && *str != '[')
- 				debug_printf_exec("running applet '%s'\n", argv[0]);
+ 		) {
- // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
+ 			o_addchr(o, '\\');
- 				run_applet_no_and_exit(a, argv);
- 			}
- 			/* re-exec ourselves with the new arguments */
- 			debug_printf_exec("re-execing applet '%s'\n", argv[0]);
- 			execvp(bb_busybox_exec_path, argv);
- 			/* If they called chroot or otherwise made the binary no longer
- 			 * executable, fall through */
  		}
+ 		len--;
  	}
- #endif
- 	debug_printf_exec("execing '%s'\n", argv[0]);
- 	execvp(argv[0], argv);
- 	bb_perror_msg("can't exec '%s'", argv[0]);
- 	_exit(EXIT_FAILURE);
  }
- /* Called after [v]fork() in run_pipe()
+ #undef HUSH_BRACE_EXP
+ /*
+  * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
+  * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
+  * Apparently, on unquoted $v bash still does globbing
+  * ("v='*.txt'; echo $v" prints all .txt files),
+  * but NOT brace expansion! Thus, there should be TWO independent
+  * quoting mechanisms on $v expansion side: one protects
+  * $v from brace expansion, and other additionally protects "$v" against globbing.
+  * We have only second one.
   */
- static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded)
- {
- 	if (command->argv)
- 		pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded);
- 	if (command->group) {
+ #ifdef HUSH_BRACE_EXP
- #if !BB_MMU
+ # define MAYBE_BRACES "{}"
- 		bb_error_msg_and_die("nested lists are not supported on NOMMU");
  #else
- 		int rcode;
+ # define MAYBE_BRACES ""
- 		debug_printf_exec("pseudo_exec: run_list\n");
- 		rcode = run_list(command->group);
- 		/* OK to leak memory by not calling free_pipe_list,
- 		 * since this process is about to exit */
- 		_exit(rcode);
  #endif
- 	}
- 	/* Can happen.  See what bash does with ">foo" by itself. */
+ /* My analysis of quoting semantics tells me that state information
- 	debug_printf("trying to pseudo_exec null command\n");
+  * is associated with a destination, not a source.
- 	_exit(EXIT_SUCCESS);
+  */
+ static void o_addqchr(o_string *o, int ch)
+ {
+ 	int sz = 1;
+ 	char *found = strchr("*?[\\" MAYBE_BRACES, ch);
+ 	if (found)
+ 		sz++;
+ 	o_grow_by(o, sz);
+ 	if (found) {
+ 		o->data[o->length] = '\\';
+ 		o->length++;
+ 	}
+ 	o->data[o->length] = ch;
+ 	o->length++;
+ 	o->data[o->length] = '\0';
  }
- #if ENABLE_HUSH_JOB
+ static void o_addQchr(o_string *o, int ch)
- static const char *get_cmdtext(struct pipe *pi)
  {
- 	char **argv;
+ 	int sz = 1;
- 	char *p;
+ 	if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
- 	int len;
+ 		sz++;
+ 		o->data[o->length] = '\\';
+ 		o->length++;
+ 	}
+ 	o_grow_by(o, sz);
+ 	o->data[o->length] = ch;
+ 	o->length++;
+ 	o->data[o->length] = '\0';
+ }
- 	/* This is subtle. ->cmdtext is created only on first backgrounding.
+ static void o_addQstr(o_string *o, const char *str, int len)
- 	 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
+ {
- 	 * On subsequent bg argv is trashed, but we won't use it */
+ 	if (!o->o_escape) {
- 	if (pi->cmdtext)
+ 		o_addblock(o, str, len);
- 		return pi->cmdtext;
+ 		return;
- 	argv = pi->cmds[0].argv;
- 	if (!argv || !argv[0]) {
- 		pi->cmdtext = xzalloc(1);
- 		return pi->cmdtext;
  	}
+ 	while (len) {
+ 		char ch;
+ 		int sz;
+ 		int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
+ 		if (ordinary_cnt > len) /* paranoia */
+ 			ordinary_cnt = len;
+ 		o_addblock(o, str, ordinary_cnt);
+ 		if (ordinary_cnt == len)
+ 			return;
+ 		str += ordinary_cnt;
+ 		len -= ordinary_cnt + 1; /* we are processing + 1 char below */
- 	len = 0;
+ 		ch = *str++;
- 	do len += strlen(*argv) + 1; while (*++argv);
+ 		sz = 1;
- 	pi->cmdtext = p = xmalloc(len);
+ 		if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
- 	argv = pi->cmds[0].argv;
+ 			sz++;
- 	do {
+ 			o->data[o->length] = '\\';
- 		len = strlen(*argv);
+ 			o->length++;
- 		memcpy(p, *argv, len);
+ 		}
- 		p += len;
+ 		o_grow_by(o, sz);
- 		*p++ = ' ';
+ 		o->data[o->length] = ch;
- 	} while (*++argv);
+ 		o->length++;
- 	p[-1] = '\0';
+ 		o->data[o->length] = '\0';
- 	return pi->cmdtext;
+ 	}
  }
- static void insert_bg_job(struct pipe *pi)
+ /* A special kind of o_string for $VAR and `cmd` expansion.
+  * It contains char* list[] at the beginning, which is grown in 16 element
+  * increments. Actual string data starts at the next multiple of 16 * (char*).
+  * list[i] contains an INDEX (int!) into this string data.
+  * It means that if list[] needs to grow, data needs to be moved higher up
+  * but list[i]'s need not be modified.
+  * NB: remembering how many list[i]'s you have there is crucial.
+  * o_finalize_list() operation post-processes this structure - calculates
+  * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
+  */
+ #if DEBUG_EXPAND || DEBUG_GLOB
+ static void debug_print_list(const char *prefix, o_string *o, int n)
  {
- 	struct pipe *thejob;
+ 	char **list = (char**)o->data;
- 	int i;
+ 	int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
+ 	int i = 0;
- 	/* Linear search for the ID of the job to use */
+ 	indent();
- 	pi->jobid = 1;
+ 	fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
- 	for (thejob = G.job_list; thejob; thejob = thejob->next)
+ 			prefix, list, n, string_start, o->length, o->maxlen);
- 		if (thejob->jobid >= pi->jobid)
+ 	while (i < n) {
- 			pi->jobid = thejob->jobid + 1;
+ 		indent();
+ 		fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
- 	/* Add thejob to the list of running jobs */
+ 				o->data + (int)list[i] + string_start,
- 	if (!G.job_list) {
+ 				o->data + (int)list[i] + string_start);
- 		thejob = G.job_list = xmalloc(sizeof(*thejob));
+ 		i++;
- 	} else {
- 		for (thejob = G.job_list; thejob->next; thejob = thejob->next)
- 			continue;
- 		thejob->next = xmalloc(sizeof(*thejob));
- 		thejob = thejob->next;
  	}
+ 	if (n) {
- 	/* Physically copy the struct job */
+ 		const char *p = o->data + (int)list[n - 1] + string_start;
- 	memcpy(thejob, pi, sizeof(struct pipe));
+ 		indent();
- 	thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
+ 		fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
- 	/* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
- 	for (i = 0; i < pi->num_cmds; i++) {
- // TODO: do we really need to have so many fields which are just dead weight
- // at execution stage?
- 		thejob->cmds[i].pid = pi->cmds[i].pid;
- 		/* all other fields are not used and stay zero */
  	}
- 	thejob->next = NULL;
- 	thejob->cmdtext = xstrdup(get_cmdtext(pi));
- 	/* We don't wait for background thejobs to return -- append it
- 	   to the list of backgrounded thejobs and leave it alone */
- 	printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
- 	G.last_bg_pid = thejob->cmds[0].pid;
- 	G.last_jobid = thejob->jobid;
  }
+ #else
+ # define debug_print_list(prefix, o, n) ((void)0)
+ #endif
- static void remove_bg_job(struct pipe *pi)
+ /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
+  * in list[n] so that it points past last stored byte so far.
+  * It returns n+1. */
+ static int o_save_ptr_helper(o_string *o, int n)
  {
- 	struct pipe *prev_pipe;
+ 	char **list = (char**)o->data;
+ 	int string_start;
+ 	int string_len;
- 	if (pi == G.job_list) {
+ 	if (!o->has_empty_slot) {
- 		G.job_list = pi->next;
+ 		string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
+ 		string_len = o->length - string_start;
+ 		if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
+ 			debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
+ 			/* list[n] points to string_start, make space for 16 more pointers */
+ 			o->maxlen += 0x10 * sizeof(list[0]);
+ 			o->data = xrealloc(o->data, o->maxlen + 1);
+ 			list = (char**)o->data;
+ 			memmove(list + n + 0x10, list + n, string_len);
+ 			o->length += 0x10 * sizeof(list[0]);
+ 		} else {
+ 			debug_printf_list("list[%d]=%d string_start=%d\n",
+ 					n, string_len, string_start);
+ 		}
  	} else {
- 		prev_pipe = G.job_list;
+ 		/* We have empty slot at list[n], reuse without growth */
- 		while (prev_pipe->next != pi)
+ 		string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
- 			prev_pipe = prev_pipe->next;
+ 		string_len = o->length - string_start;
- 		prev_pipe->next = pi->next;
+ 		debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
+ 				n, string_len, string_start);
+ 		o->has_empty_slot = 0;
  	}
- 	if (G.job_list)
+ 	list[n] = (char*)(ptrdiff_t)string_len;
- 		G.last_jobid = G.job_list->jobid;
+ 	return n + 1;
- 	else
- 		G.last_jobid = 0;
  }
- /* Remove a backgrounded job */
+ /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
- static void delete_finished_bg_job(struct pipe *pi)
+ static int o_get_last_ptr(o_string *o, int n)
  {
- 	remove_bg_job(pi);
+ 	char **list = (char**)o->data;
- 	pi->stopped_cmds = 0;
+ 	int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
- 	free_pipe(pi, 0);
- 	free(pi);
+ 	return ((int)(ptrdiff_t)list[n-1]) + string_start;
  }
- #endif /* JOB */
- /* Check to see if any processes have exited -- if they
+ #ifdef HUSH_BRACE_EXP
-  * have, figure out why and see if a job has completed */
+ /* There in a GNU extension, GLOB_BRACE, but it is not usable:
- static int checkjobs(struct pipe* fg_pipe)
+  * first, it processes even {a} (no commas), second,
- {
+  * I didn't manage to make it return strings when they don't match
- 	int attributes;
+  * existing files. Need to re-implement it.
- 	int status;
+  */
- #if ENABLE_HUSH_JOB
- 	struct pipe *pi;
- #endif
- 	pid_t childpid;
- 	int rcode = 0;
- 	attributes = WUNTRACED;
+ /* Helper */
- 	if (fg_pipe == NULL)
+ static int glob_needed(const char *s)
- 		attributes |= WNOHANG;
+ {
+ 	while (*s) {
+ 		if (*s == '\\') {
+ 			if (!s[1])
+ 				return 0;
+ 			s += 2;
+ 			continue;
+ 		}
+ 		if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
+ 			return 1;
+ 		s++;
+ 	}
+ 	return 0;
+ }
+ /* Return pointer to next closing brace or to comma */
+ static const char *next_brace_sub(const char *cp)
+ {
+ 	unsigned depth = 0;
+ 	cp++;
+ 	while (*cp != '\0') {
+ 		if (*cp == '\\') {
+ 			if (*++cp == '\0')
+ 				break;
+ 			cp++;
+ 			continue;
+ 		}
+ 		 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
+ 			break;
+ 		if (*cp++ == '{') /*}*/
+ 			depth++;
+ 	}
- /* Do we do this right?
+ 	return *cp != '\0' ? cp : NULL;
-  * bash-3.00# sleep 20 | false
+ }
-  * <ctrl-Z pressed>
+ /* Recursive brace globber. Note: may garble pattern[]. */
-  * [3]+  Stopped          sleep 20 | false
+ static int glob_brace(char *pattern, o_string *o, int n)
-  * bash-3.00# echo $?
+ {
-  * 1   <========== bg pipe is not fully done, but exitcode is already known!
+ 	char *new_pattern_buf;
-  */
+ 	const char *begin;
+ 	const char *next;
+ 	const char *rest;
+ 	const char *p;
+ 	size_t rest_len;
- //FIXME: non-interactive bash does not continue even if all processes in fg pipe
+ 	debug_printf_glob("glob_brace('%s')\n", pattern);
- //are stopped. Testcase: "cat | cat" in a script (not on command line)
- // + killall -STOP cat
-  wait_more:
+ 	begin = pattern;
- // TODO: safe_waitpid?
+ 	while (1) {
- 	while ((childpid = waitpid(-1, &status, attributes)) > 0) {
+ 		if (*begin == '\0')
- 		int i;
+ 			goto simple_glob;
- 		const int dead = WIFEXITED(status) || WIFSIGNALED(status);
+ 		if (*begin == '{') /*}*/ {
- #if DEBUG_JOBS
+ 			/* Find the first sub-pattern and at the same time
- 		if (WIFSTOPPED(status))
+ 			 * find the rest after the closing brace */
- 			debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
+ 			next = next_brace_sub(begin);
- 					childpid, WSTOPSIG(status), WEXITSTATUS(status));
+ 			if (next == NULL) {
- 		if (WIFSIGNALED(status))
+ 				/* An illegal expression */
- 			debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
+ 				goto simple_glob;
- 					childpid, WTERMSIG(status), WEXITSTATUS(status));
+ 			}
- 		if (WIFEXITED(status))
+ 			/*{*/ if (*next == '}') {
- 			debug_printf_jobs("pid %d exited, exitcode %d\n",
+ 				/* "{abc}" with no commas - illegal
- 					childpid, WEXITSTATUS(status));
+ 				 * brace expr, disregard and skip it */
- #endif
+ 				begin = next + 1;
- 		/* Were we asked to wait for fg pipe? */
+ 				continue;
- 		if (fg_pipe) {
- 			for (i = 0; i < fg_pipe->num_cmds; i++) {
- 				debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
- 				if (fg_pipe->cmds[i].pid != childpid)
- 					continue;
- 				/* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
- 				if (dead) {
- 					fg_pipe->cmds[i].pid = 0;
- 					fg_pipe->alive_cmds--;
- 					if (i == fg_pipe->num_cmds - 1) {
- 						/* last process gives overall exitstatus */
- 						rcode = WEXITSTATUS(status);
- 						IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
- 					}
- 				} else {
- 					fg_pipe->cmds[i].is_stopped = 1;
- 					fg_pipe->stopped_cmds++;
- 				}
- 				debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
- 						fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
- 				if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
- 					/* All processes in fg pipe have exited/stopped */
- #if ENABLE_HUSH_JOB
- 					if (fg_pipe->alive_cmds)
- 						insert_bg_job(fg_pipe);
- #endif
- 					return rcode;
- 				}
- 				/* There are still running processes in the fg pipe */
- 				goto wait_more; /* do waitpid again */
  			}
- 			/* it wasnt fg_pipe, look for process in bg pipes */
+ 			break;
  		}
+ 		if (*begin == '\\' && begin[1] != '\0')
+ 			begin++;
+ 		begin++;
+ 	}
+ 	debug_printf_glob("begin:%s\n", begin);
+ 	debug_printf_glob("next:%s\n", next);
- #if ENABLE_HUSH_JOB
+ 	/* Now find the end of the whole brace expression */
- 		/* We asked to wait for bg or orphaned children */
+ 	rest = next;
- 		/* No need to remember exitcode in this case */
+ 	/*{*/ while (*rest != '}') {
- 		for (pi = G.job_list; pi; pi = pi->next) {
+ 		rest = next_brace_sub(rest);
- 			for (i = 0; i < pi->num_cmds; i++) {
+ 		if (rest == NULL) {
- 				if (pi->cmds[i].pid == childpid)
+ 			/* An illegal expression */
- 					goto found_pi_and_prognum;
+ 			goto simple_glob;
- 			}
  		}
- 		/* Happens when shell is used as init process (init=/bin/sh) */
+ 		debug_printf_glob("rest:%s\n", rest);
- 		debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
+ 	}
- 		continue; /* do waitpid again */
+ 	rest_len = strlen(++rest) + 1;
-  found_pi_and_prognum:
+ 	/* We are sure the brace expression is well-formed */
- 		if (dead) {
- 			/* child exited */
+ 	/* Allocate working buffer large enough for our work */
- 			pi->cmds[i].pid = 0;
+ 	new_pattern_buf = xmalloc(strlen(pattern));
- 			pi->alive_cmds--;
- 			if (!pi->alive_cmds) {
+ 	/* We have a brace expression.  BEGIN points to the opening {,
- 				printf(JOB_STATUS_FORMAT, pi->jobid,
+ 	 * NEXT points past the terminator of the first element, and REST
- 						"Done", pi->cmdtext);
+ 	 * points past the final }.  We will accumulate result names from
- 				delete_finished_bg_job(pi);
+ 	 * recursive runs for each brace alternative in the buffer using
+ 	 * GLOB_APPEND.  */
+ 	p = begin + 1;
+ 	while (1) {
+ 		/* Construct the new glob expression */
+ 		memcpy(
+ 			mempcpy(
+ 				mempcpy(new_pattern_buf,
+ 					/* We know the prefix for all sub-patterns */
+ 					pattern, begin - pattern),
+ 				p, next - p),
+ 			rest, rest_len);
+ 		/* Note: glob_brace() may garble new_pattern_buf[].
+ 		 * That's why we re-copy prefix every time (1st memcpy above).
+ 		 */
+ 		n = glob_brace(new_pattern_buf, o, n);
+ 		/*{*/ if (*next == '}') {
+ 			/* We saw the last entry */
+ 			break;
+ 		}
+ 		p = next + 1;
+ 		next = next_brace_sub(next);
+ 	}
+ 	free(new_pattern_buf);
+ 	return n;
+  simple_glob:
+ 	{
+ 		int gr;
+ 		glob_t globdata;
+ 		memset(&globdata, 0, sizeof(globdata));
+ 		gr = glob(pattern, 0, NULL, &globdata);
+ 		debug_printf_glob("glob('%s'):%d\n", pattern, gr);
+ 		if (gr != 0) {
+ 			if (gr == GLOB_NOMATCH) {
+ 				globfree(&globdata);
+ 				/* NB: garbles parameter */
+ 				unbackslash(pattern);
+ 				o_addstr_with_NUL(o, pattern);
+ 				debug_printf_glob("glob pattern '%s' is literal\n", pattern);
+ 				return o_save_ptr_helper(o, n);
+ 			}
+ 			if (gr == GLOB_NOSPACE)
+ 				bb_error_msg_and_die(bb_msg_memory_exhausted);
+ 			/* GLOB_ABORTED? Only happens with GLOB_ERR flag,
+ 			 * but we didn't specify it. Paranoia again. */
+ 			bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
+ 		}
+ 		if (globdata.gl_pathv && globdata.gl_pathv[0]) {
+ 			char **argv = globdata.gl_pathv;
+ 			while (1) {
+ 				o_addstr_with_NUL(o, *argv);
+ 				n = o_save_ptr_helper(o, n);
+ 				argv++;
+ 				if (!*argv)
+ 					break;
  			}
- 		} else {
- 			/* child stopped */
- 			pi->cmds[i].is_stopped = 1;
- 			pi->stopped_cmds++;
  		}
- #endif
+ 		globfree(&globdata);
- 	} /* while (waitpid succeeds)... */
+ 	}
+ 	return n;
+ }
+ /* Performs globbing on last list[],
+  * saving each result as a new list[].
+  */
+ static int o_glob(o_string *o, int n)
+ {
+ 	char *pattern, *copy;
- 	/* wait found no children or failed */
+ 	debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
+ 	if (!o->data)
+ 		return o_save_ptr_helper(o, n);
+ 	pattern = o->data + o_get_last_ptr(o, n);
+ 	debug_printf_glob("glob pattern '%s'\n", pattern);
+ 	if (!glob_needed(pattern)) {
+ 		/* unbackslash last string in o in place, fix length */
+ 		o->length = unbackslash(pattern) - o->data;
+ 		debug_printf_glob("glob pattern '%s' is literal\n", pattern);
+ 		return o_save_ptr_helper(o, n);
+ 	}
- 	if (childpid && errno != ECHILD)
+ 	copy = xstrdup(pattern);
- 		bb_perror_msg("waitpid");
+ 	/* "forget" pattern in o */
- 	return rcode;
+ 	o->length = pattern - o->data;
+ 	n = glob_brace(copy, o, n);
+ 	free(copy);
+ 	if (DEBUG_GLOB)
+ 		debug_print_list("o_glob returning", o, n);
+ 	return n;
  }
- #if ENABLE_HUSH_JOB
+ #else
- static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
+ /* Helper */
+ static int glob_needed(const char *s)
  {
- 	pid_t p;
+ 	while (*s) {
- 	int rcode = checkjobs(fg_pipe);
+ 		if (*s == '\\') {
- 	/* Job finished, move the shell to the foreground */
+ 			if (!s[1])
- 	p = getpgid(0); /* pgid of our process */
+ 				return 0;
- 	debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
+ 			s += 2;
- 	tcsetpgrp(G.interactive_fd, p);
+ 			continue;
- 	return rcode;
+ 		}
+ 		if (*s == '*' || *s == '[' || *s == '?')
+ 			return 1;
+ 		s++;
+ 	}
+ 	return 0;
  }
- #endif
+ /* Performs globbing on last list[],
+  * saving each result as a new list[].
- /* run_pipe() starts all the jobs, but doesn't wait for anything
-  * to finish.  See checkjobs().
-  *
-  * return code is normally -1, when the caller has to wait for children
-  * to finish to determine the exit status of the pipe.  If the pipe
-  * is a simple builtin command, however, the action is done by the
-  * time run_pipe returns, and the exit code is provided as the
-  * return value.
-  *
-  * The input of the pipe is always stdin, the output is always
-  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
-  * because it tries to avoid running the command substitution in
-  * subshell, when that is in fact necessary.  The subshell process
-  * now has its stdout directed to the input of the appropriate pipe,
-  * so this routine is noticeably simpler.
-  *
-  * Returns -1 only if started some children. IOW: we have to
-  * mask out retvals of builtins etc with 0xff!
   */
- static int run_pipe(struct pipe *pi)
+ static int o_glob(o_string *o, int n)
  {
- 	int i;
+ 	glob_t globdata;
- 	int nextin;
+ 	int gr;
- 	int pipefds[2];		/* pipefds[0] is for reading */
+ 	char *pattern;
- 	struct command *command;
- 	char **argv_expanded;
- 	char **argv;
- 	const struct built_in_command *x;
- 	char *p;
- 	/* it is not always needed, but we aim to smaller code */
- 	int squirrel[] = { -1, -1, -1 };
- 	int rcode;
- 	const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG);
- 	debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
- #if ENABLE_HUSH_JOB
+ 	debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
- 	pi->pgrp = -1;
+ 	if (!o->data)
- #endif
+ 		return o_save_ptr_helper(o, n);
- 	pi->alive_cmds = 1;
+ 	pattern = o->data + o_get_last_ptr(o, n);
- 	pi->stopped_cmds = 0;
+ 	debug_printf_glob("glob pattern '%s'\n", pattern);
+ 	if (!glob_needed(pattern)) {
+  literal:
+ 		/* unbackslash last string in o in place, fix length */
+ 		o->length = unbackslash(pattern) - o->data;
+ 		debug_printf_glob("glob pattern '%s' is literal\n", pattern);
+ 		return o_save_ptr_helper(o, n);
+ 	}
- 	/* Check if this is a simple builtin (not part of a pipe).
+ 	memset(&globdata, 0, sizeof(globdata));
- 	 * Builtins within pipes have to fork anyway, and are handled in
+ 	/* Can't use GLOB_NOCHECK: it does not unescape the string.
- 	 * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
+ 	 * If we glob "*.\*" and don't find anything, we need
+ 	 * to fall back to using literal "*.*", but GLOB_NOCHECK
+ 	 * will return "*.\*"!
  	 */
- 	command = &(pi->cmds[0]);
+ 	gr = glob(pattern, 0, NULL, &globdata);
+ 	debug_printf_glob("glob('%s'):%d\n", pattern, gr);
- #if ENABLE_HUSH_FUNCTIONS
+ 	if (gr != 0) {
- 	if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) {
+ 		if (gr == GLOB_NOMATCH) {
- 		/* We "execute" function definition */
+ 			globfree(&globdata);
- 		bb_error_msg("here we ought to remember function definition, and go on");
+ 			goto literal;
- 		return EXIT_SUCCESS;
+ 		}
+ 		if (gr == GLOB_NOSPACE)
+ 			bb_error_msg_and_die(bb_msg_memory_exhausted);
+ 		/* GLOB_ABORTED? Only happens with GLOB_ERR flag,
+ 		 * but we didn't specify it. Paranoia again. */
+ 		bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
+ 	}
+ 	if (globdata.gl_pathv && globdata.gl_pathv[0]) {
+ 		char **argv = globdata.gl_pathv;
+ 		/* "forget" pattern in o */
+ 		o->length = pattern - o->data;
+ 		while (1) {
+ 			o_addstr_with_NUL(o, *argv);
+ 			n = o_save_ptr_helper(o, n);
+ 			argv++;
+ 			if (!*argv)
+ 				break;
+ 		}
  	}
+ 	globfree(&globdata);
+ 	if (DEBUG_GLOB)
+ 		debug_print_list("o_glob returning", o, n);
+ 	return n;
+ }
  #endif
- 	if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) {
+ /* If o->o_glob == 1, glob the string so far remembered.
- 		debug_printf("non-subshell grouping\n");
+  * Otherwise, just finish current list[] and start new */
- 		setup_redirects(command, squirrel);
+ static int o_save_ptr(o_string *o, int n)
- 		debug_printf_exec(": run_list\n");
+ {
- 		rcode = run_list(command->group) & 0xff;
+ 	if (o->o_glob) { /* if globbing is requested */
- 		restore_redirects(squirrel);
+ 		/* If o->has_empty_slot, list[n] was already globbed
- 		debug_printf_exec("run_pipe return %d\n", rcode);
+ 		 * (if it was requested back then when it was filled)
- 		IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
+ 		 * so don't do that again! */
- 		return rcode;
+ 		if (!o->has_empty_slot)
+ 			return o_glob(o, n); /* o_save_ptr_helper is inside */
  	}
+ 	return o_save_ptr_helper(o, n);
+ }
- 	argv = command->argv;
+ /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
- 	argv_expanded = NULL;
+ static char **o_finalize_list(o_string *o, int n)
+ {
- 	if (single_and_fg && argv != NULL) {
+ 	char **list;
- 		char **new_env = NULL;
+ 	int string_start;
- 		char **old_env = NULL;
- 		i = command->assignment_cnt;
+ 	n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
- 		if (i != 0 && argv[i] == NULL) {
+ 	if (DEBUG_EXPAND)
- 			/* assignments, but no command: set local environment */
+ 		debug_print_list("finalized", o, n);
- 			for (i = 0; argv[i] != NULL; i++) {
+ 	debug_printf_expand("finalized n:%d\n", n);
- 				debug_printf("local environment set: %s\n", argv[i]);
+ 	list = (char**)o->data;
- 				p = expand_string_to_string(argv[i]);
+ 	string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
- 				set_local_var(p, 0);
+ 	list[--n] = NULL;
- 			}
+ 	while (n) {
- 			return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
+ 		n--;
- 		}
+ 		list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
+ 	}
+ 	return list;
+ }
- 		/* Expand the rest into (possibly) many strings each */
- 		argv_expanded = expand_strvec_to_strvec(argv + i);
- 		for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
+ /* Expansion can recurse */
- 			if (strcmp(argv_expanded[0], x->cmd) != 0)
+ #if ENABLE_HUSH_TICK
- 				continue;
+ static int process_command_subs(o_string *dest, const char *s);
- 			if (x->function == builtin_exec && argv_expanded[1] == NULL) {
- 				debug_printf("exec with redirects only\n");
- 				setup_redirects(command, NULL);
- 				rcode = EXIT_SUCCESS;
- 				goto clean_up_and_ret1;
- 			}
- 			debug_printf("builtin inline %s\n", argv_expanded[0]);
- 			/* XXX setup_redirects acts on file descriptors, not FILEs.
- 			 * This is perfect for work that comes after exec().
- 			 * Is it really safe for inline use?  Experimentally,
- 			 * things seem to work with glibc. */
- 			setup_redirects(command, squirrel);
- 			new_env = expand_assignments(argv, command->assignment_cnt);
- 			old_env = putenv_all_and_save_old(new_env);
- 			debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
- 			rcode = x->function(argv_expanded) & 0xff;
- #if ENABLE_FEATURE_SH_STANDALONE
-  clean_up_and_ret:
  #endif
- 			restore_redirects(squirrel);
+ static char *expand_string_to_string(const char *str);
- 			free_strings_and_unsetenv(new_env, 1);
+ #if BB_MMU
- 			putenv_all(old_env);
+ #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
- 			free(old_env); /* not free_strings()! */
+ 	parse_stream_dquoted(dest, input, dquote_end)
-  clean_up_and_ret1:
- 			free(argv_expanded);
- 			IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
- 			debug_printf_exec("run_pipe return %d\n", rcode);
- 			return rcode;
- 		}
- #if ENABLE_FEATURE_SH_STANDALONE
- 		i = find_applet_by_name(argv_expanded[0]);
- 		if (i >= 0 && APPLET_IS_NOFORK(i)) {
- 			setup_redirects(command, squirrel);
- 			save_nofork_data(&G.nofork_save);
- 			new_env = expand_assignments(argv, command->assignment_cnt);
- 			old_env = putenv_all_and_save_old(new_env);
- 			debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
- 			rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
- 			goto clean_up_and_ret;
- 		}
  #endif
- 	}
+ static int parse_stream_dquoted(o_string *as_string,
+ 		o_string *dest,
+ 		struct in_str *input,
+ 		int dquote_end);
- 	/* NB: argv_expanded may already be created, and that
+ /* expand_strvec_to_strvec() takes a list of strings, expands
- 	 * might include `cmd` runs! Do not rerun it! We *must*
+  * all variable references within and returns a pointer to
- 	 * use argv_expanded if it's non-NULL */
+  * a list of expanded strings, possibly with larger number
+  * of strings. (Think VAR="a b"; echo $VAR).
+  * This new list is allocated as a single malloc block.
+  * NULL-terminated list of char* pointers is at the beginning of it,
+  * followed by strings themself.
+  * Caller can deallocate entire list by single free(list). */
- 	/* Disable job control signals for shell (parent) and
+ /* Store given string, finalizing the word and starting new one whenever
- 	 * for initial child code after fork */
+  * we encounter IFS char(s). This is used for expanding variable values.
- 	set_jobctrl_sighandler(SIG_IGN);
+  * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
+ static int expand_on_ifs(o_string *output, int n, const char *str)
+ {
+ 	while (1) {
+ 		int word_len = strcspn(str, G.ifs);
+ 		if (word_len) {
+ 			if (output->o_escape || !output->o_glob)
+ 				o_addQstr(output, str, word_len);
+ 			else /* protect backslashes against globbing up :) */
+ 				o_addblock_duplicate_backslash(output, str, word_len);
+ 			str += word_len;
+ 		}
+ 		if (!*str)  /* EOL - do not finalize word */
+ 			break;
+ 		o_addchr(output, '\0');
+ 		debug_print_list("expand_on_ifs", output, n);
+ 		n = o_save_ptr(output, n);
+ 		str += strspn(str, G.ifs); /* skip ifs chars */
+ 	}
+ 	debug_print_list("expand_on_ifs[1]", output, n);
+ 	return n;
+ }
- 	/* Going to fork a child per each pipe member */
+ /* Helper to expand $((...)) and heredoc body. These act as if
- 	pi->alive_cmds = 0;
+  * they are in double quotes, with the exception that they are not :).
- 	nextin = 0;
+  * Just the rules are similar: "expand only $var and `cmd`"
+  *
+  * Returns malloced string.
+  * As an optimization, we return NULL if expansion is not needed.
+  */
+ static char *expand_pseudo_dquoted(const char *str)
+ {
+ 	char *exp_str;
+ 	struct in_str input;
+ 	o_string dest = NULL_O_STRING;
- 	for (i = 0; i < pi->num_cmds; i++) {
+ 	if (strchr(str, '$') == NULL
- #if !BB_MMU
+ #if ENABLE_HUSH_TICK
- 		volatile nommu_save_t nommu_save;
+ 	 && strchr(str, '`') == NULL
- 		nommu_save.new_env = NULL;
- 		nommu_save.old_env = NULL;
- 		nommu_save.argv = NULL;
  #endif
- 		command = &(pi->cmds[i]);
+ 	) {
- 		if (command->argv) {
+ 		return NULL;
- 			debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]);
+ 	}
- 		} else
- 			debug_printf_exec(": pipe member with no argv\n");
- 		/* pipes are inserted between pairs of commands */
+ 	/* We need to expand. Example:
- 		pipefds[0] = 0;
+ 	 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
- 		pipefds[1] = 1;
+ 	 */
- 		if ((i + 1) < pi->num_cmds)
+ 	setup_string_in_str(&input, str);
- 			xpipe(pipefds);
+ 	parse_stream_dquoted(NULL, &dest, &input, EOF);
+ 	//bb_error_msg("'%s' -> '%s'", str, dest.data);
+ 	exp_str = expand_string_to_string(dest.data);
+ 	//bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
+ 	o_free_unsafe(&dest);
+ 	return exp_str;
+ }
- 		command->pid = BB_MMU ? fork() : vfork();
+ /* Expand all variable references in given string, adding words to list[]
- 		if (!command->pid) { /* child */
+  * at n, n+1,... positions. Return updated n (so that list[n] is next one
- 			if (ENABLE_HUSH_JOB)
+  * to be filled). This routine is extremely tricky: has to deal with
- 				die_sleep = 0; /* let nofork's xfuncs die */
+  * variables/parameters with whitespace, $* and $@, and constructs like
- #if ENABLE_HUSH_JOB
+  * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
- 			/* Every child adds itself to new process group
+ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
- 			 * with pgid == pid_of_first_child_in_pipe */
+ {
- 			if (G.run_list_level == 1 && G.interactive_fd) {
+ 	/* or_mask is either 0 (normal case) or 0x80 -
- 				pid_t pgrp;
+ 	 * expansion of right-hand side of assignment == 1-element expand.
- 				/* Don't do pgrp restore anymore on fatal signals */
+ 	 * It will also do no globbing, and thus we must not backslash-quote!
- 				set_fatal_sighandler(SIG_DFL);
+ 	 */
- 				pgrp = pi->pgrp;
+ 	char ored_ch;
- 				if (pgrp < 0) /* true for 1st process only */
+ 	char *p;
- 					pgrp = getpid();
- 				if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
+ 	ored_ch = 0;
- 					/* We do it in *every* child, not just first,
- 					 * to avoid races */
+ 	debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
- 					tcsetpgrp(G.interactive_fd, pgrp);
+ 	debug_print_list("expand_vars_to_list", output, n);
+ 	n = o_save_ptr(output, n);
+ 	debug_print_list("expand_vars_to_list[0]", output, n);
+ 	while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
+ 		char first_ch;
+ 		int i;
+ 		char *dyn_val = NULL;
+ 		const char *val = NULL;
+ #if ENABLE_HUSH_TICK
+ 		o_string subst_result = NULL_O_STRING;
+ #endif
+ #if ENABLE_SH_MATH_SUPPORT
+ 		char arith_buf[sizeof(arith_t)*3 + 2];
+ #endif
+ 		o_addblock(output, arg, p - arg);
+ 		debug_print_list("expand_vars_to_list[1]", output, n);
+ 		arg = ++p;
+ 		p = strchr(p, SPECIAL_VAR_SYMBOL);
+ 		first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
+ 		/* "$@" is special. Even if quoted, it can still
+ 		 * expand to nothing (not even an empty string) */
+ 		if ((first_ch & 0x7f) != '@')
+ 			ored_ch |= first_ch;
+ 		switch (first_ch & 0x7f) {
+ 		/* Highest bit in first_ch indicates that var is double-quoted */
+ 		case '$': /* pid */
+ 			val = utoa(G.root_pid);
+ 			break;
+ 		case '!': /* bg pid */
+ 			val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
+ 			break;
+ 		case '?': /* exitcode */
+ 			val = utoa(G.last_exitcode);
+ 			break;
+ 		case '#': /* argc */
+ 			if (arg[1] != SPECIAL_VAR_SYMBOL)
+ 				/* actually, it's a ${#var} */
+ 				goto case_default;
+ 			val = utoa(G.global_argc ? G.global_argc-1 : 0);
+ 			break;
+ 		case '*':
+ 		case '@':
+ 			i = 1;
+ 			if (!G.global_argv[i])
+ 				break;
+ 			ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
+ 			if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
+ 				smallint sv = output->o_escape;
+ 				/* unquoted var's contents should be globbed, so don't escape */
+ 				output->o_escape = 0;
+ 				while (G.global_argv[i]) {
+ 					n = expand_on_ifs(output, n, G.global_argv[i]);
+ 					debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
+ 					if (G.global_argv[i++][0] && G.global_argv[i]) {
+ 						/* this argv[] is not empty and not last:
+ 						 * put terminating NUL, start new word */
+ 						o_addchr(output, '\0');
+ 						debug_print_list("expand_vars_to_list[2]", output, n);
+ 						n = o_save_ptr(output, n);
+ 						debug_print_list("expand_vars_to_list[3]", output, n);
+ 					}
+ 				}
+ 				output->o_escape = sv;
+ 			} else
+ 			/* If or_mask is nonzero, we handle assignment 'a=....$@.....'
+ 			 * and in this case should treat it like '$*' - see 'else...' below */
+ 			if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
+ 				while (1) {
+ 					o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
+ 					if (++i >= G.global_argc)
+ 						break;
+ 					o_addchr(output, '\0');
+ 					debug_print_list("expand_vars_to_list[4]", output, n);
+ 					n = o_save_ptr(output, n);
+ 				}
+ 			} else { /* quoted $*: add as one word */
+ 				while (1) {
+ 					o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
+ 					if (!G.global_argv[++i])
+ 						break;
+ 					if (G.ifs[0])
+ 						o_addchr(output, G.ifs[0]);
  				}
  			}
+ 			break;
+ 		case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
+ 			/* "Empty variable", used to make "" etc to not disappear */
+ 			arg++;
+ 			ored_ch = 0x80;
+ 			break;
+ #if ENABLE_HUSH_TICK
+ 		case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
+ 			*p = '\0';
+ 			arg++;
+ 			/* Can't just stuff it into output o_string,
+ 			 * expanded result may need to be globbed
+ 			 * and $IFS-splitted */
+ 			debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
+ 			G.last_exitcode = process_command_subs(&subst_result, arg);
+ 			debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
+ 			val = subst_result.data;
+ 			goto store_val;
  #endif
- 			xmove_fd(nextin, 0);
+ #if ENABLE_SH_MATH_SUPPORT
- 			xmove_fd(pipefds[1], 1); /* write end */
+ 		case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
- 			if (pipefds[0] > 1)
+ 			arith_eval_hooks_t hooks;
- 				close(pipefds[0]); /* read end */
+ 			arith_t res;
- 			/* Like bash, explicit redirects override pipes,
+ 			int errcode;
- 			 * and the pipe fd is available for dup'ing. */
+ 			char *exp_str;
- 			setup_redirects(command, NULL);
+ 			arg++; /* skip '+' */
+ 			*p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
+ 			debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
+ 			exp_str = expand_pseudo_dquoted(arg);
+ 			hooks.lookupvar = get_local_var_value;
+ 			hooks.setvar = set_local_var_from_halves;
+ 			hooks.endofname = endofname;
+ 			res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
+ 			free(exp_str);
+ 			if (errcode < 0) {
+ 				const char *msg = "error in arithmetic";
+ 				switch (errcode) {
+ 				case -3:
+ 					msg = "exponent less than 0";
+ 					break;
+ 				case -2:
+ 					msg = "divide by 0";
+ 					break;
+ 				case -5:
+ 					msg = "expression recursion loop detected";
+ 					break;
+ 				}
+ 				die_if_script(msg);
+ 			}
+ 			debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
+ 			sprintf(arith_buf, arith_t_fmt, res);
+ 			val = arith_buf;
+ 			break;
+ 		}
+ #endif
+ 		default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
+ 		case_default: {
+ 			bool exp_len = false;
+ 			bool exp_null = false;
+ 			char *var = arg;
+ 			char exp_save = exp_save; /* for compiler */
+ 			char exp_op = exp_op; /* for compiler */
+ 			char *exp_word = exp_word; /* for compiler */
+ 			size_t exp_off = 0;
+ 			*p = '\0';
+ 			arg[0] = first_ch & 0x7f;
+ 			/* prepare for expansions */
+ 			if (var[0] == '#') {
+ 				/* handle length expansion ${#var} */
+ 				exp_len = true;
+ 				++var;
+ 			} else {
+ 				/* maybe handle parameter expansion */
+ 				exp_off = strcspn(var, ":-=+?%#");
+ 				if (!var[exp_off])
+ 					exp_off = 0;
+ 				if (exp_off) {
+ 					exp_save = var[exp_off];
+ 					exp_null = exp_save == ':';
+ 					exp_word = var + exp_off;
+ 					if (exp_null)
+ 						++exp_word;
+ 					exp_op = *exp_word++;
+ 					var[exp_off] = '\0';
+ 				}
+ 			}
+ 			/* lookup the variable in question */
+ 			if (isdigit(var[0])) {
+ 				/* handle_dollar() should have vetted var for us */
+ 				i = xatoi_u(var);
+ 				if (i < G.global_argc)
+ 					val = G.global_argv[i];
+ 				/* else val remains NULL: $N with too big N */
+ 			} else
+ 				val = get_local_var_value(var);
+ 			/* handle any expansions */
+ 			if (exp_len) {
+ 				debug_printf_expand("expand: length of '%s' = ", val);
+ 				val = utoa(val ? strlen(val) : 0);
+ 				debug_printf_expand("%s\n", val);
+ 			} else if (exp_off) {
+ 				if (exp_op == '%' || exp_op == '#') {
+ 					if (val) {
+ 						/* we need to do a pattern match */
+ 						bool match_at_left;
+ 						char *loc;
+ 						scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
+ 						if (exp_op == *exp_word)	/* ## or %% */
+ 							++exp_word;
+ 						val = dyn_val = xstrdup(val);
+ 						loc = scan(dyn_val, exp_word, match_at_left);
+ 						if (match_at_left) /* # or ## */
+ 							val = loc;
+ 						else if (loc) /* % or %% and match was found */
+ 							*loc = '\0';
+ 					}
+ 				} else {
+ 					/* we need to do an expansion */
+ 					int exp_test = (!val || (exp_null && !val[0]));
+ 					if (exp_op == '+')
+ 						exp_test = !exp_test;
+ 					debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
+ 						exp_null ? "true" : "false", exp_test);
+ 					if (exp_test) {
+ 						if (exp_op == '?') {
+ //TODO: how interactive bash aborts expansion mid-command?
+ 							/* ${var?[error_msg_if_unset]} */
+ 							/* ${var:?[error_msg_if_unset_or_null]} */
+ 							/* mimic bash message */
+ 							die_if_script("%s: %s",
+ 								var,
+ 								exp_word[0] ? exp_word : "parameter null or not set"
+ 							);
+ 						} else {
+ 							val = exp_word;
+ 						}
+ 						if (exp_op == '=') {
+ 							/* ${var=[word]} or ${var:=[word]} */
+ 							if (isdigit(var[0]) || var[0] == '#') {
+ 								/* mimic bash message */
+ 								die_if_script("$%s: cannot assign in this way", var);
+ 								val = NULL;
+ 							} else {
+ 								char *new_var = xasprintf("%s=%s", var, val);
+ 								set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
+ 							}
+ 						}
+ 					}
+ 				}
+ 				var[exp_off] = exp_save;
+ 			}
+ 			arg[0] = first_ch;
+ #if ENABLE_HUSH_TICK
+  store_val:
+ #endif
+ 			if (!(first_ch & 0x80)) { /* unquoted $VAR */
+ 				debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
+ 				if (val) {
+ 					/* unquoted var's contents should be globbed, so don't escape */
+ 					smallint sv = output->o_escape;
+ 					output->o_escape = 0;
+ 					n = expand_on_ifs(output, n, val);
+ 					val = NULL;
+ 					output->o_escape = sv;
+ 				}
+ 			} else { /* quoted $VAR, val will be appended below */
+ 				debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
+ 			}
+ 		} /* default: */
+ 		} /* switch (char after <SPECIAL_VAR_SYMBOL>) */
+ 		if (val) {
+ 			o_addQstr(output, val, strlen(val));
+ 		}
+ 		free(dyn_val);
+ 		/* Do the check to avoid writing to a const string */
+ 		if (*p != SPECIAL_VAR_SYMBOL)
+ 			*p = SPECIAL_VAR_SYMBOL;
+ #if ENABLE_HUSH_TICK
+ 		o_free(&subst_result);
+ #endif
+ 		arg = ++p;
+ 	} /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
+ 	if (arg[0]) {
+ 		debug_print_list("expand_vars_to_list[a]", output, n);
+ 		/* this part is literal, and it was already pre-quoted
+ 		 * if needed (much earlier), do not use o_addQstr here! */
+ 		o_addstr_with_NUL(output, arg);
+ 		debug_print_list("expand_vars_to_list[b]", output, n);
+ 	} else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
+ 	 && !(ored_ch & 0x80) /* and all vars were not quoted. */
+ 	) {
+ 		n--;
+ 		/* allow to reuse list[n] later without re-growth */
+ 		output->has_empty_slot = 1;
+ 	} else {
+ 		o_addchr(output, '\0');
+ 	}
+ 	return n;
+ }
+ static char **expand_variables(char **argv, int or_mask)
+ {
+ 	int n;
+ 	char **list;
+ 	char **v;
+ 	o_string output = NULL_O_STRING;
+ 	if (or_mask & 0x100) {
+ 		output.o_escape = 1; /* protect against globbing for "$var" */
+ 		/* (unquoted $var will temporarily switch it off) */
+ 		output.o_glob = 1;
+ 	}
+ 	n = 0;
+ 	v = argv;
+ 	while (*v) {
+ 		n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
+ 		v++;
+ 	}
+ 	debug_print_list("expand_variables", &output, n);
+ 	/* output.data (malloced in one block) gets returned in "list" */
+ 	list = o_finalize_list(&output, n);
+ 	debug_print_strings("expand_variables[1]", list);
+ 	return list;
+ }
+ static char **expand_strvec_to_strvec(char **argv)
+ {
+ 	return expand_variables(argv, 0x100);
+ }
+ #if ENABLE_HUSH_BASH_COMPAT
+ static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
+ {
+ 	return expand_variables(argv, 0x80);
+ }
+ #endif
+ #ifdef CMD_SINGLEWORD_NOGLOB_COND
+ static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
+ {
+ 	int n;
+ 	char **list;
+ 	char **v;
+ 	o_string output = NULL_O_STRING;
+ 	n = 0;
+ 	v = argv;
+ 	while (*v) {
+ 		int is_var = is_well_formed_var_name(*v, '=');
+ 		/* is_var * 0x80: singleword expansion for vars */
+ 		n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
+ 		/* Subtle! expand_vars_to_list did not glob last word yet.
+ 		 * It does this only when fed with further data.
+ 		 * Therefore we set globbing flags AFTER it, not before:
+ 		 */
+ 		/* if it is not recognizably abc=...; then: */
+ 		output.o_escape = !is_var; /* protect against globbing for "$var" */
+ 		/* (unquoted $var will temporarily switch it off) */
+ 		output.o_glob = !is_var; /* and indeed do globbing */
+ 		v++;
+ 	}
+ 	debug_print_list("expand_cond", &output, n);
+ 	/* output.data (malloced in one block) gets returned in "list" */
+ 	list = o_finalize_list(&output, n);
+ 	debug_print_strings("expand_cond[1]", list);
+ 	return list;
+ }
+ #endif
+ /* Used for expansion of right hand of assignments */
+ /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
+  * "v=/bin/c*" */
+ static char *expand_string_to_string(const char *str)
+ {
+ 	char *argv[2], **list;
+ 	argv[0] = (char*)str;
+ 	argv[1] = NULL;
+ 	list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
+ 	if (HUSH_DEBUG)
+ 		if (!list[0] || list[1])
+ 			bb_error_msg_and_die("BUG in varexp2");
+ 	/* actually, just move string 2*sizeof(char*) bytes back */
+ 	overlapping_strcpy((char*)list, list[0]);
+ 	unbackslash((char*)list);
+ 	debug_printf_expand("string_to_string='%s'\n", (char*)list);
+ 	return (char*)list;
+ }
+ /* Used for "eval" builtin */
+ static char* expand_strvec_to_string(char **argv)
+ {
+ 	char **list;
+ 	list = expand_variables(argv, 0x80);
+ 	/* Convert all NULs to spaces */
+ 	if (list[0]) {
+ 		int n = 1;
+ 		while (list[n]) {
+ 			if (HUSH_DEBUG)
+ 				if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
+ 					bb_error_msg_and_die("BUG in varexp3");
+ 			/* bash uses ' ' regardless of $IFS contents */
+ 			list[n][-1] = ' ';
+ 			n++;
+ 		}
+ 	}
+ 	overlapping_strcpy((char*)list, list[0]);
+ 	debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
+ 	return (char*)list;
+ }
+ static char **expand_assignments(char **argv, int count)
+ {
+ 	int i;
+ 	char **p = NULL;
+ 	/* Expand assignments into one string each */
+ 	for (i = 0; i < count; i++) {
+ 		p = add_string_to_strings(p, expand_string_to_string(argv[i]));
+ 	}
+ 	return p;
+ }
+ #if BB_MMU
+ /* never called */
+ void re_execute_shell(char ***to_free, const char *s,
+ 		char *g_argv0, char **g_argv,
+ 		char **builtin_argv) NORETURN;
+ static void reset_traps_to_defaults(void)
+ {
+ 	/* This function is always called in a child shell
+ 	 * after fork (not vfork, NOMMU doesn't use this function).
+ 	 */
+ 	unsigned sig;
+ 	unsigned mask;
+ 	/* Child shells are not interactive.
+ 	 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
+ 	 * Testcase: (while :; do :; done) + ^Z should background.
+ 	 * Same goes for SIGTERM, SIGHUP, SIGINT.
+ 	 */
+ 	if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
+ 		return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
+ 	/* Switching off SPECIAL_INTERACTIVE_SIGS.
+ 	 * Stupid. It can be done with *single* &= op, but we can't use
+ 	 * the fact that G.blocked_set is implemented as a bitmask
+ 	 * in libc... */
+ 	mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
+ 	sig = 1;
+ 	while (1) {
+ 		if (mask & 1) {
+ 			/* Careful. Only if no trap or trap is not "" */
+ 			if (!G.traps || !G.traps[sig] || G.traps[sig][0])
+ 				sigdelset(&G.blocked_set, sig);
+ 		}
+ 		mask >>= 1;
+ 		if (!mask)
+ 			break;
+ 		sig++;
+ 	}
+ 	/* Our homegrown sig mask is saner to work with :) */
+ 	G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
+ 	/* Resetting all traps to default except empty ones */
+ 	mask = G.non_DFL_mask;
+ 	if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
+ 		if (!G.traps[sig] || !G.traps[sig][0])
+ 			continue;
+ 		free(G.traps[sig]);
+ 		G.traps[sig] = NULL;
+ 		/* There is no signal for 0 (EXIT) */
+ 		if (sig == 0)
+ 			continue;
+ 		/* There was a trap handler, we just removed it.
+ 		 * But if sig still has non-DFL handling,
+ 		 * we should not unblock the sig. */
+ 		if (mask & 1)
+ 			continue;
+ 		sigdelset(&G.blocked_set, sig);
+ 	}
+ 	sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+ }
+ #else /* !BB_MMU */
+ static void re_execute_shell(char ***to_free, const char *s,
+ 		char *g_argv0, char **g_argv,
+ 		char **builtin_argv) NORETURN;
+ static void re_execute_shell(char ***to_free, const char *s,
+ 		char *g_argv0, char **g_argv,
+ 		char **builtin_argv)
+ {
+ #define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
+ 	/* delims + 2 * (number of bytes in printed hex numbers) */
+ 	char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
+ 	char *heredoc_argv[4];
+ 	struct variable *cur;
+ # if ENABLE_HUSH_FUNCTIONS
+ 	struct function *funcp;
+ # endif
+ 	char **argv, **pp;
+ 	unsigned cnt;
+ 	unsigned long long empty_trap_mask;
+ 	if (!g_argv0) { /* heredoc */
+ 		argv = heredoc_argv;
+ 		argv[0] = (char *) G.argv0_for_re_execing;
+ 		argv[1] = (char *) "-<";
+ 		argv[2] = (char *) s;
+ 		argv[3] = NULL;
+ 		pp = &argv[3]; /* used as pointer to empty environment */
+ 		goto do_exec;
+ 	}
+ 	cnt = 0;
+ 	pp = builtin_argv;
+ 	if (pp) while (*pp++)
+ 		cnt++;
+ 	empty_trap_mask = 0;
+ 	if (G.traps) {
+ 		int sig;
+ 		for (sig = 1; sig < NSIG; sig++) {
+ 			if (G.traps[sig] && !G.traps[sig][0])
+ 				empty_trap_mask |= 1LL << sig;
+ 		}
+ 	}
+ 	sprintf(param_buf, NOMMU_HACK_FMT
+ 			, (unsigned) G.root_pid
+ 			, (unsigned) G.root_ppid
+ 			, (unsigned) G.last_bg_pid
+ 			, (unsigned) G.last_exitcode
+ 			, cnt
+ 			, empty_trap_mask
+ 			IF_HUSH_LOOPS(, G.depth_of_loop)
+ 			);
+ #undef NOMMU_HACK_FMT
+ 	/* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
+ 	 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
+ 	 */
+ 	cnt += 6;
+ 	for (cur = G.top_var; cur; cur = cur->next) {
+ 		if (!cur->flg_export || cur->flg_read_only)
+ 			cnt += 2;
+ 	}
+ # if ENABLE_HUSH_FUNCTIONS
+ 	for (funcp = G.top_func; funcp; funcp = funcp->next)
+ 		cnt += 3;
+ # endif
+ 	pp = g_argv;
+ 	while (*pp++)
+ 		cnt++;
+ 	*to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
+ 	*pp++ = (char *) G.argv0_for_re_execing;
+ 	*pp++ = param_buf;
+ 	for (cur = G.top_var; cur; cur = cur->next) {
+ 		if (cur->varstr == hush_version_str)
+ 			continue;
+ 		if (cur->flg_read_only) {
+ 			*pp++ = (char *) "-R";
+ 			*pp++ = cur->varstr;
+ 		} else if (!cur->flg_export) {
+ 			*pp++ = (char *) "-V";
+ 			*pp++ = cur->varstr;
+ 		}
+ 	}
+ # if ENABLE_HUSH_FUNCTIONS
+ 	for (funcp = G.top_func; funcp; funcp = funcp->next) {
+ 		*pp++ = (char *) "-F";
+ 		*pp++ = funcp->name;
+ 		*pp++ = funcp->body_as_string;
+ 	}
+ # endif
+ 	/* We can pass activated traps here. Say, -Tnn:trap_string
+ 	 *
+ 	 * However, POSIX says that subshells reset signals with traps
+ 	 * to SIG_DFL.
+ 	 * I tested bash-3.2 and it not only does that with true subshells
+ 	 * of the form ( list ), but with any forked children shells.
+ 	 * I set trap "echo W" WINCH; and then tried:
+ 	 *
+ 	 * { echo 1; sleep 20; echo 2; } &
+ 	 * while true; do echo 1; sleep 20; echo 2; break; done &
+ 	 * true | { echo 1; sleep 20; echo 2; } | cat
+ 	 *
+ 	 * In all these cases sending SIGWINCH to the child shell
+ 	 * did not run the trap. If I add trap "echo V" WINCH;
+ 	 * _inside_ group (just before echo 1), it works.
+ 	 *
+ 	 * I conclude it means we don't need to pass active traps here.
+ 	 * Even if we would use signal handlers instead of signal masking
+ 	 * in order to implement trap handling,
+ 	 * exec syscall below resets signals to SIG_DFL for us.
+ 	 */
+ 	*pp++ = (char *) "-c";
+ 	*pp++ = (char *) s;
+ 	if (builtin_argv) {
+ 		while (*++builtin_argv)
+ 			*pp++ = *builtin_argv;
+ 		*pp++ = (char *) "";
+ 	}
+ 	*pp++ = g_argv0;
+ 	while (*g_argv)
+ 		*pp++ = *g_argv++;
+ 	/* *pp = NULL; - is already there */
+ 	pp = environ;
+  do_exec:
+ 	debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
+ 	sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
+ 	execve(bb_busybox_exec_path, argv, pp);
+ 	/* Fallback. Useful for init=/bin/hush usage etc */
+ 	if (argv[0][0] == '/')
+ 		execve(argv[0], argv, pp);
+ 	xfunc_error_retval = 127;
+ 	bb_error_msg_and_die("can't re-execute the shell");
+ }
+ #endif  /* !BB_MMU */
+ static void setup_heredoc(struct redir_struct *redir)
+ {
+ 	struct fd_pair pair;
+ 	pid_t pid;
+ 	int len, written;
+ 	/* the _body_ of heredoc (misleading field name) */
+ 	const char *heredoc = redir->rd_filename;
+ 	char *expanded;
+ #if !BB_MMU
+ 	char **to_free;
+ #endif
+ 	expanded = NULL;
+ 	if (!(redir->rd_dup & HEREDOC_QUOTED)) {
+ 		expanded = expand_pseudo_dquoted(heredoc);
+ 		if (expanded)
+ 			heredoc = expanded;
+ 	}
+ 	len = strlen(heredoc);
+ 	close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
+ 	xpiped_pair(pair);
+ 	xmove_fd(pair.rd, redir->rd_fd);
+ 	/* Try writing without forking. Newer kernels have
+ 	 * dynamically growing pipes. Must use non-blocking write! */
+ 	ndelay_on(pair.wr);
+ 	while (1) {
+ 		written = write(pair.wr, heredoc, len);
+ 		if (written <= 0)
+ 			break;
+ 		len -= written;
+ 		if (len == 0) {
+ 			close(pair.wr);
+ 			free(expanded);
+ 			return;
+ 		}
+ 		heredoc += written;
+ 	}
+ 	ndelay_off(pair.wr);
+ 	/* Okay, pipe buffer was not big enough */
+ 	/* Note: we must not create a stray child (bastard? :)
+ 	 * for the unsuspecting parent process. Child creates a grandchild
+ 	 * and exits before parent execs the process which consumes heredoc
+ 	 * (that exec happens after we return from this function) */
+ #if !BB_MMU
+ 	to_free = NULL;
+ #endif
+ 	pid = vfork();
+ 	if (pid < 0)
+ 		bb_perror_msg_and_die("vfork");
+ 	if (pid == 0) {
+ 		/* child */
+ 		disable_restore_tty_pgrp_on_exit();
+ 		pid = BB_MMU ? fork() : vfork();
+ 		if (pid < 0)
+ 			bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
+ 		if (pid != 0)
+ 			_exit(0);
+ 		/* grandchild */
+ 		close(redir->rd_fd); /* read side of the pipe */
+ #if BB_MMU
+ 		full_write(pair.wr, heredoc, len); /* may loop or block */
+ 		_exit(0);
+ #else
+ 		/* Delegate blocking writes to another process */
+ 		xmove_fd(pair.wr, STDOUT_FILENO);
+ 		re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
+ #endif
+ 	}
+ 	/* parent */
+ #if ENABLE_HUSH_FAST
+ 	G.count_SIGCHLD++;
+ //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
+ #endif
+ 	enable_restore_tty_pgrp_on_exit();
+ #if !BB_MMU
+ 	free(to_free);
+ #endif
+ 	close(pair.wr);
+ 	free(expanded);
+ 	wait(NULL); /* wait till child has died */
+ }
+ /* squirrel != NULL means we squirrel away copies of stdin, stdout,
+  * and stderr if they are redirected. */
+ static int setup_redirects(struct command *prog, int squirrel[])
+ {
+ 	int openfd, mode;
+ 	struct redir_struct *redir;
+ 	for (redir = prog->redirects; redir; redir = redir->next) {
+ 		if (redir->rd_type == REDIRECT_HEREDOC2) {
+ 			/* rd_fd<<HERE case */
+ 			if (squirrel && redir->rd_fd < 3
+ 			 && squirrel[redir->rd_fd] < 0
+ 			) {
+ 				squirrel[redir->rd_fd] = dup(redir->rd_fd);
+ 			}
+ 			/* for REDIRECT_HEREDOC2, rd_filename holds _contents_
+ 			 * of the heredoc */
+ 			debug_printf_parse("set heredoc '%s'\n",
+ 					redir->rd_filename);
+ 			setup_heredoc(redir);
+ 			continue;
+ 		}
+ 		if (redir->rd_dup == REDIRFD_TO_FILE) {
+ 			/* rd_fd<*>file case (<*> is <,>,>>,<>) */
+ 			char *p;
+ 			if (redir->rd_filename == NULL) {
+ 				/* Something went wrong in the parse.
+ 				 * Pretend it didn't happen */
+ 				bb_error_msg("bug in redirect parse");
+ 				continue;
+ 			}
+ 			mode = redir_table[redir->rd_type].mode;
+ 			p = expand_string_to_string(redir->rd_filename);
+ 			openfd = open_or_warn(p, mode);
+ 			free(p);
+ 			if (openfd < 0) {
+ 			/* this could get lost if stderr has been redirected, but
+ 			 * bash and ash both lose it as well (though zsh doesn't!) */
+ //what the above comment tries to say?
+ 				return 1;
+ 			}
+ 		} else {
+ 			/* rd_fd<*>rd_dup or rd_fd<*>- cases */
+ 			openfd = redir->rd_dup;
+ 		}
+ 		if (openfd != redir->rd_fd) {
+ 			if (squirrel && redir->rd_fd < 3
+ 			 && squirrel[redir->rd_fd] < 0
+ 			) {
+ 				squirrel[redir->rd_fd] = dup(redir->rd_fd);
+ 			}
+ 			if (openfd == REDIRFD_CLOSE) {
+ 				/* "n>-" means "close me" */
+ 				close(redir->rd_fd);
+ 			} else {
+ 				xdup2(openfd, redir->rd_fd);
+ 				if (redir->rd_dup == REDIRFD_TO_FILE)
+ 					close(openfd);
+ 			}
+ 		}
+ 	}
+ 	return 0;
+ }
+ static void restore_redirects(int squirrel[])
+ {
+ 	int i, fd;
+ 	for (i = 0; i < 3; i++) {
+ 		fd = squirrel[i];
+ 		if (fd != -1) {
+ 			/* We simply die on error */
+ 			xmove_fd(fd, i);
+ 		}
+ 	}
+ }
+ static void free_pipe_list(struct pipe *head);
+ /* Return code is the exit status of the pipe */
+ static void free_pipe(struct pipe *pi)
+ {
+ 	char **p;
+ 	struct command *command;
+ 	struct redir_struct *r, *rnext;
+ 	int a, i;
+ 	if (pi->stopped_cmds > 0) /* why? */
+ 		return;
+ 	debug_printf_clean("run pipe: (pid %d)\n", getpid());
+ 	for (i = 0; i < pi->num_cmds; i++) {
+ 		command = &pi->cmds[i];
+ 		debug_printf_clean("  command %d:\n", i);
+ 		if (command->argv) {
+ 			for (a = 0, p = command->argv; *p; a++, p++) {
+ 				debug_printf_clean("   argv[%d] = %s\n", a, *p);
+ 			}
+ 			free_strings(command->argv);
+ 			command->argv = NULL;
+ 		}
+ 		/* not "else if": on syntax error, we may have both! */
+ 		if (command->group) {
+ 			debug_printf_clean("   begin group (cmd_type:%d)\n",
+ 					command->cmd_type);
+ 			free_pipe_list(command->group);
+ 			debug_printf_clean("   end group\n");
+ 			command->group = NULL;
+ 		}
+ 		/* else is crucial here.
+ 		 * If group != NULL, child_func is meaningless */
+ #if ENABLE_HUSH_FUNCTIONS
+ 		else if (command->child_func) {
+ 			debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
+ 			command->child_func->parent_cmd = NULL;
+ 		}
+ #endif
+ #if !BB_MMU
+ 		free(command->group_as_string);
+ 		command->group_as_string = NULL;
+ #endif
+ 		for (r = command->redirects; r; r = rnext) {
+ 			debug_printf_clean("   redirect %d%s",
+ 					r->rd_fd, redir_table[r->rd_type].descrip);
+ 			/* guard against the case >$FOO, where foo is unset or blank */
+ 			if (r->rd_filename) {
+ 				debug_printf_clean(" fname:'%s'\n", r->rd_filename);
+ 				free(r->rd_filename);
+ 				r->rd_filename = NULL;
+ 			}
+ 			debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
+ 			rnext = r->next;
+ 			free(r);
+ 		}
+ 		command->redirects = NULL;
+ 	}
+ 	free(pi->cmds);   /* children are an array, they get freed all at once */
+ 	pi->cmds = NULL;
+ #if ENABLE_HUSH_JOB
+ 	free(pi->cmdtext);
+ 	pi->cmdtext = NULL;
+ #endif
+ }
+ static void free_pipe_list(struct pipe *head)
+ {
+ 	struct pipe *pi, *next;
+ 	for (pi = head; pi; pi = next) {
+ #if HAS_KEYWORDS
+ 		debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
+ #endif
+ 		free_pipe(pi);
+ 		debug_printf_clean("pipe followup code %d\n", pi->followup);
+ 		next = pi->next;
+ 		/*pi->next = NULL;*/
+ 		free(pi);
+ 	}
+ }
+ static int run_list(struct pipe *pi);
+ #if BB_MMU
+ #define parse_stream(pstring, input, end_trigger) \
+ 	parse_stream(input, end_trigger)
+ #endif
+ static struct pipe *parse_stream(char **pstring,
+ 		struct in_str *input,
+ 		int end_trigger);
+ static void parse_and_run_string(const char *s);
+ static char *find_in_path(const char *arg)
+ {
+ 	char *ret = NULL;
+ 	const char *PATH = get_local_var_value("PATH");
+ 	if (!PATH)
+ 		return NULL;
+ 	while (1) {
+ 		const char *end = strchrnul(PATH, ':');
+ 		int sz = end - PATH; /* must be int! */
+ 		free(ret);
+ 		if (sz != 0) {
+ 			ret = xasprintf("%.*s/%s", sz, PATH, arg);
+ 		} else {
+ 			/* We have xxx::yyyy in $PATH,
+ 			 * it means "use current dir" */
+ 			ret = xstrdup(arg);
+ 		}
+ 		if (access(ret, F_OK) == 0)
+ 			break;
+ 		if (*end == '\0') {
+ 			free(ret);
+ 			return NULL;
+ 		}
+ 		PATH = end + 1;
+ 	}
+ 	return ret;
+ }
+ static const struct built_in_command* find_builtin_helper(const char *name,
+ 		const struct built_in_command *x,
+ 		const struct built_in_command *end)
+ {
+ 	while (x != end) {
+ 		if (strcmp(name, x->cmd) != 0) {
+ 			x++;
+ 			continue;
+ 		}
+ 		debug_printf_exec("found builtin '%s'\n", name);
+ 		return x;
+ 	}
+ 	return NULL;
+ }
+ static const struct built_in_command* find_builtin1(const char *name)
+ {
+ 	return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
+ }
+ static const struct built_in_command* find_builtin(const char *name)
+ {
+ 	const struct built_in_command *x = find_builtin1(name);
+ 	if (x)
+ 		return x;
+ 	return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
+ }
- 			/* Restore default handlers just prior to exec */
+ #if ENABLE_HUSH_FUNCTIONS
- 			set_jobctrl_sighandler(SIG_DFL);
+ static struct function **find_function_slot(const char *name)
- 			set_misc_sighandler(SIG_DFL);
+ {
- 			signal(SIGCHLD, SIG_DFL);
+ 	struct function **funcpp = &G.top_func;
- 			/* Stores to nommu_save list of env vars putenv'ed
+ 	while (*funcpp) {
- 			 * (NOMMU, on MMU we don't need that) */
+ 		if (strcmp(name, (*funcpp)->name) == 0) {
- 			/* cast away volatility... */
+ 			break;
- 			pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
- 			/* pseudo_exec() does not return */
  		}
- 		/* parent */
+ 		funcpp = &(*funcpp)->next;
- #if !BB_MMU
+ 	}
- 		/* Clean up after vforked child */
+ 	return funcpp;
- 		free(nommu_save.argv);
+ }
- 		free_strings_and_unsetenv(nommu_save.new_env, 1);
- 		putenv_all(nommu_save.old_env);
+ static const struct function *find_function(const char *name)
- #endif
+ {
- 		free(argv_expanded);
+ 	const struct function *funcp = *find_function_slot(name);
- 		argv_expanded = NULL;
+ 	if (funcp)
- 		if (command->pid < 0) { /* [v]fork failed */
+ 		debug_printf_exec("found function '%s'\n", name);
- 			/* Clearly indicate, was it fork or vfork */
+ 	return funcp;
- 			bb_perror_msg(BB_MMU ? "fork" : "vfork");
+ }
+ /* Note: takes ownership on name ptr */
+ static struct function *new_function(char *name)
+ {
+ 	struct function **funcpp = find_function_slot(name);
+ 	struct function *funcp = *funcpp;
+ 	if (funcp != NULL) {
+ 		struct command *cmd = funcp->parent_cmd;
+ 		debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
+ 		if (!cmd) {
+ 			debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
+ 			free(funcp->name);
+ 			/* Note: if !funcp->body, do not free body_as_string!
+ 			 * This is a special case of "-F name body" function:
+ 			 * body_as_string was not malloced! */
+ 			if (funcp->body) {
+ 				free_pipe_list(funcp->body);
+ # if !BB_MMU
+ 				free(funcp->body_as_string);
+ # endif
+ 			}
  		} else {
- 			pi->alive_cmds++;
+ 			debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
- #if ENABLE_HUSH_JOB
+ 			cmd->argv[0] = funcp->name;
- 			/* Second and next children need to know pid of first one */
+ 			cmd->group = funcp->body;
- 			if (pi->pgrp < 0)
+ # if !BB_MMU
- 				pi->pgrp = command->pid;
+ 			cmd->group_as_string = funcp->body_as_string;
- #endif
+ # endif
  		}
+ 	} else {
+ 		debug_printf_exec("remembering new function '%s'\n", name);
+ 		funcp = *funcpp = xzalloc(sizeof(*funcp));
+ 		/*funcp->next = NULL;*/
+ 	}
+ 	funcp->name = name;
+ 	return funcp;
+ }
+ static void unset_func(const char *name)
+ {
+ 	struct function **funcpp = find_function_slot(name);
+ 	struct function *funcp = *funcpp;
+ 	if (funcp != NULL) {
+ 		debug_printf_exec("freeing function '%s'\n", funcp->name);
+ 		*funcpp = funcp->next;
+ 		/* funcp is unlinked now, deleting it.
+ 		 * Note: if !funcp->body, the function was created by
+ 		 * "-F name body", do not free ->body_as_string
+ 		 * and ->name as they were not malloced. */
+ 		if (funcp->body) {
+ 			free_pipe_list(funcp->body);
+ 			free(funcp->name);
+ # if !BB_MMU
+ 			free(funcp->body_as_string);
+ # endif
+ 		}
+ 		free(funcp);
+ 	}
+ }
- 		if (i)
+ # if BB_MMU
- 			close(nextin);
+ #define exec_function(to_free, funcp, argv) \
- 		if ((i + 1) < pi->num_cmds)
+ 	exec_function(funcp, argv)
- 			close(pipefds[1]); /* write end */
+ # endif
- 		/* Pass read (output) pipe end to next iteration */
+ static void exec_function(char ***to_free,
- 		nextin = pipefds[0];
+ 		const struct function *funcp,
+ 		char **argv) NORETURN;
+ static void exec_function(char ***to_free,
+ 		const struct function *funcp,
+ 		char **argv)
+ {
+ # if BB_MMU
+ 	int n = 1;
+ 	argv[0] = G.global_argv[0];
+ 	G.global_argv = argv;
+ 	while (*++argv)
+ 		n++;
+ 	G.global_argc = n;
+ 	/* On MMU, funcp->body is always non-NULL */
+ 	n = run_list(funcp->body);
+ 	fflush_all();
+ 	_exit(n);
+ # else
+ 	re_execute_shell(to_free,
+ 			funcp->body_as_string,
+ 			G.global_argv[0],
+ 			argv + 1,
+ 			NULL);
+ # endif
+ }
+ static int run_function(const struct function *funcp, char **argv)
+ {
+ 	int rc;
+ 	save_arg_t sv;
+ 	smallint sv_flg;
+ 	save_and_replace_G_args(&sv, argv);
+ 	/* "we are in function, ok to use return" */
+ 	sv_flg = G.flag_return_in_progress;
+ 	G.flag_return_in_progress = -1;
+ # if ENABLE_HUSH_LOCAL
+ 	G.func_nest_level++;
+ # endif
+ 	/* On MMU, funcp->body is always non-NULL */
+ # if !BB_MMU
+ 	if (!funcp->body) {
+ 		/* Function defined by -F */
+ 		parse_and_run_string(funcp->body_as_string);
+ 		rc = G.last_exitcode;
+ 	} else
+ # endif
+ 	{
+ 		rc = run_list(funcp->body);
  	}
- 	if (!pi->alive_cmds) {
+ # if ENABLE_HUSH_LOCAL
- 		debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
+ 	{
- 		return 1;
+ 		struct variable *var;
+ 		struct variable **var_pp;
+ 		var_pp = &G.top_var;
+ 		while ((var = *var_pp) != NULL) {
+ 			if (var->func_nest_level < G.func_nest_level) {
+ 				var_pp = &var->next;
+ 				continue;
+ 			}
+ 			/* Unexport */
+ 			if (var->flg_export)
+ 				bb_unsetenv(var->varstr);
+ 			/* Remove from global list */
+ 			*var_pp = var->next;
+ 			/* Free */
+ 			if (!var->max_len)
+ 				free(var->varstr);
+ 			free(var);
+ 		}
+ 		G.func_nest_level--;
  	}
+ # endif
+ 	G.flag_return_in_progress = sv_flg;
- 	debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
+ 	restore_G_args(&sv, argv);
- 	return -1;
+ 	return rc;
  }
+ #endif /* ENABLE_HUSH_FUNCTIONS */
- #ifndef debug_print_tree
- static void debug_print_tree(struct pipe *pi, int lvl)
+ #if BB_MMU
- {
+ #define exec_builtin(to_free, x, argv) \
- 	static const char *const PIPE[] = {
+ 	exec_builtin(x, argv)
- 		[PIPE_SEQ] = "SEQ",
+ #else
- 		[PIPE_AND] = "AND",
+ #define exec_builtin(to_free, x, argv) \
- 		[PIPE_OR ] = "OR" ,
+ 	exec_builtin(to_free, argv)
- 		[PIPE_BG ] = "BG" ,
- 	};
- 	static const char *RES[] = {
- 		[RES_NONE ] = "NONE" ,
- #if ENABLE_HUSH_IF
- 		[RES_IF   ] = "IF"   ,
- 		[RES_THEN ] = "THEN" ,
- 		[RES_ELIF ] = "ELIF" ,
- 		[RES_ELSE ] = "ELSE" ,
- 		[RES_FI   ] = "FI"   ,
  #endif
- #if ENABLE_HUSH_LOOPS
+ static void exec_builtin(char ***to_free,
- 		[RES_FOR  ] = "FOR"  ,
+ 		const struct built_in_command *x,
- 		[RES_WHILE] = "WHILE",
+ 		char **argv) NORETURN;
- 		[RES_UNTIL] = "UNTIL",
+ static void exec_builtin(char ***to_free,
- 		[RES_DO   ] = "DO"   ,
+ 		const struct built_in_command *x,
- 		[RES_DONE ] = "DONE" ,
+ 		char **argv)
+ {
+ #if BB_MMU
+ 	int rcode = x->function(argv);
+ 	fflush_all();
+ 	_exit(rcode);
+ #else
+ 	/* On NOMMU, we must never block!
+ 	 * Example: { sleep 99 | read line; } & echo Ok
+ 	 */
+ 	re_execute_shell(to_free,
+ 			argv[0],
+ 			G.global_argv[0],
+ 			G.global_argv + 1,
+ 			argv);
  #endif
- #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
+ }
- 		[RES_IN   ] = "IN"   ,
+ static void execvp_or_die(char **argv) NORETURN;
+ static void execvp_or_die(char **argv)
+ {
+ 	debug_printf_exec("execing '%s'\n", argv[0]);
+ 	sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
+ 	/* if FEATURE_SH_STANDALONE, "exec <applet_name>" should work,
+ 	 * therefore we should use BB_EXECVP, not execvp */
+ 	BB_EXECVP(argv[0], argv);
+ 	bb_perror_msg("can't execute '%s'", argv[0]);
+ 	_exit(127); /* bash compat */
+ }
+ #if BB_MMU
+ #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
+ 	pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
+ #define pseudo_exec(nommu_save, command, argv_expanded) \
+ 	pseudo_exec(command, argv_expanded)
  #endif
- #if ENABLE_HUSH_CASE
- 		[RES_CASE ] = "CASE" ,
+ /* Called after [v]fork() in run_pipe, or from builtin_exec.
- 		[RES_MATCH] = "MATCH",
+  * Never returns.
- 		[RES_CASEI] = "CASEI",
+  * Don't exit() here.  If you don't exec, use _exit instead.
- 		[RES_ESAC ] = "ESAC" ,
+  * The at_exit handlers apparently confuse the calling process,
+  * in particular stdin handling.  Not sure why? -- because of vfork! (vda) */
+ static void pseudo_exec_argv(nommu_save_t *nommu_save,
+ 		char **argv, int assignment_cnt,
+ 		char **argv_expanded) NORETURN;
+ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
+ 		char **argv, int assignment_cnt,
+ 		char **argv_expanded)
+ {
+ 	char **new_env;
+ 	/* Case when we are here: ... | var=val | ... */
+ 	if (!argv[assignment_cnt])
+ 		_exit(EXIT_SUCCESS);
+ 	new_env = expand_assignments(argv, assignment_cnt);
+ #if BB_MMU
+ 	set_vars_and_save_old(new_env);
+ 	free(new_env); /* optional */
+ 	/* we can also destroy set_vars_and_save_old's return value,
+ 	 * to save memory */
+ #else
+ 	nommu_save->new_env = new_env;
+ 	nommu_save->old_vars = set_vars_and_save_old(new_env);
  #endif
- 		[RES_XXXX ] = "XXXX" ,
+ 	if (argv_expanded) {
- 		[RES_SNTX ] = "SNTX" ,
+ 		argv = argv_expanded;
- 	};
+ 	} else {
- 	static const char *const GRPTYPE[] = {
+ 		argv = expand_strvec_to_strvec(argv + assignment_cnt);
- 		"()",
+ #if !BB_MMU
- 		"{}",
+ 		nommu_save->argv = argv;
- #if ENABLE_HUSH_FUNCTIONS
- 		"func()",
  #endif
- 	};
+ 	}
- 	int pin, prn;
+ #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
+ 	if (strchr(argv[0], '/') != NULL)
+ 		goto skip;
+ #endif
- 	pin = 0;
+ 	/* Check if the command matches any of the builtins.
- 	while (pi) {
+ 	 * Depending on context, this might be redundant.  But it's
- 		fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
+ 	 * easier to waste a few CPU cycles than it is to figure out
- 				pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
+ 	 * if this is one of those cases.
- 		prn = 0;
+ 	 */
- 		while (prn < pi->num_cmds) {
+ 	{
- 			struct command *command = &pi->cmds[prn];
+ 		/* On NOMMU, it is more expensive to re-execute shell
- 			char **argv = command->argv;
+ 		 * just in order to run echo or test builtin.
+ 		 * It's better to skip it here and run corresponding
+ 		 * non-builtin later. */
+ 		const struct built_in_command *x;
+ 		x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
+ 		if (x) {
+ 			exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
+ 		}
+ 	}
+ #if ENABLE_HUSH_FUNCTIONS
+ 	/* Check if the command matches any functions */
+ 	{
+ 		const struct function *funcp = find_function(argv[0]);
+ 		if (funcp) {
+ 			exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
+ 		}
+ 	}
+ #endif
- 			fprintf(stderr, "%*s prog %d assignment_cnt:%d", lvl*2, "", prn, command->assignment_cnt);
+ #if ENABLE_FEATURE_SH_STANDALONE
- 			if (command->group) {
+ 	/* Check if the command matches any busybox applets */
- 				fprintf(stderr, " group %s: (argv=%p)\n",
+ 	{
- 						GRPTYPE[command->grp_type],
+ 		int a = find_applet_by_name(argv[0]);
- 						argv);
+ 		if (a >= 0) {
- 				debug_print_tree(command->group, lvl+1);
+ # if BB_MMU /* see above why on NOMMU it is not allowed */
- 				prn++;
+ 			if (APPLET_IS_NOEXEC(a)) {
- 				continue;
+ 				debug_printf_exec("running applet '%s'\n", argv[0]);
- 			}
+ 				run_applet_no_and_exit(a, argv);
- 			if (argv) while (*argv) {
- 				fprintf(stderr, " '%s'", *argv);
- 				argv++;
  			}
- 			fprintf(stderr, "\n");
+ # endif
- 			prn++;
+ 			/* Re-exec ourselves */
+ 			debug_printf_exec("re-execing applet '%s'\n", argv[0]);
+ 			sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
+ 			execv(bb_busybox_exec_path, argv);
+ 			/* If they called chroot or otherwise made the binary no longer
+ 			 * executable, fall through */
  		}
- 		pi = pi->next;
- 		pin++;
  	}
- }
  #endif
- /* NB: called by pseudo_exec, and therefore must not modify any
+ #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
-  * global data until exec/_exit (we can be a child after vfork!) */
+  skip:
- static int run_list(struct pipe *pi)
- {
- #if ENABLE_HUSH_CASE
- 	char *case_word = NULL;
- #endif
- #if ENABLE_HUSH_LOOPS
- 	struct pipe *loop_top = NULL;
- 	char *for_varname = NULL;
- 	char **for_lcur = NULL;
- 	char **for_list = NULL;
  #endif
- 	smallint flag_skip = 1;
+ 	execvp_or_die(argv);
- 	smalluint rcode = 0; /* probably just for compiler */
+ }
- #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
- 	smalluint cond_code = 0;
+ /* Called after [v]fork() in run_pipe
+  */
+ static void pseudo_exec(nommu_save_t *nommu_save,
+ 		struct command *command,
+ 		char **argv_expanded) NORETURN;
+ static void pseudo_exec(nommu_save_t *nommu_save,
+ 		struct command *command,
+ 		char **argv_expanded)
+ {
+ 	if (command->argv) {
+ 		pseudo_exec_argv(nommu_save, command->argv,
+ 				command->assignment_cnt, argv_expanded);
+ 	}
+ 	if (command->group) {
+ 		/* Cases when we are here:
+ 		 * ( list )
+ 		 * { list } &
+ 		 * ... | ( list ) | ...
+ 		 * ... | { list } | ...
+ 		 */
+ #if BB_MMU
+ 		int rcode;
+ 		debug_printf_exec("pseudo_exec: run_list\n");
+ 		reset_traps_to_defaults();
+ 		rcode = run_list(command->group);
+ 		/* OK to leak memory by not calling free_pipe_list,
+ 		 * since this process is about to exit */
+ 		_exit(rcode);
  #else
- 	enum { cond_code = 0, };
+ 		re_execute_shell(&nommu_save->argv_from_re_execing,
+ 				command->group_as_string,
+ 				G.global_argv[0],
+ 				G.global_argv + 1,
+ 				NULL);
  #endif
- 	/*enum reserved_style*/ smallint rword = RES_NONE;
+ 	}
- 	/*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
+ 	/* Case when we are here: ... | >file */
+ 	debug_printf_exec("pseudo_exec'ed null command\n");
+ 	_exit(EXIT_SUCCESS);
+ }
+ #if ENABLE_HUSH_JOB
+ static const char *get_cmdtext(struct pipe *pi)
+ {
+ 	char **argv;
+ 	char *p;
+ 	int len;
+ 	/* This is subtle. ->cmdtext is created only on first backgrounding.
+ 	 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
+ 	 * On subsequent bg argv is trashed, but we won't use it */
+ 	if (pi->cmdtext)
+ 		return pi->cmdtext;
+ 	argv = pi->cmds[0].argv;
+ 	if (!argv || !argv[0]) {
+ 		pi->cmdtext = xzalloc(1);
+ 		return pi->cmdtext;
+ 	}
+ 	len = 0;
+ 	do {
+ 		len += strlen(*argv) + 1;
+ 	} while (*++argv);
+ 	p = xmalloc(len);
+ 	pi->cmdtext = p;
+ 	argv = pi->cmds[0].argv;
+ 	do {
+ 		len = strlen(*argv);
+ 		memcpy(p, *argv, len);
+ 		p += len;
+ 		*p++ = ' ';
+ 	} while (*++argv);
+ 	p[-1] = '\0';
+ 	return pi->cmdtext;
+ }
+ static void insert_bg_job(struct pipe *pi)
+ {
+ 	struct pipe *job, **jobp;
+ 	int i;
+ 	/* Linear search for the ID of the job to use */
+ 	pi->jobid = 1;
+ 	for (job = G.job_list; job; job = job->next)
+ 		if (job->jobid >= pi->jobid)
+ 			pi->jobid = job->jobid + 1;
+ 	/* Add job to the list of running jobs */
+ 	jobp = &G.job_list;
+ 	while ((job = *jobp) != NULL)
+ 		jobp = &job->next;
+ 	job = *jobp = xmalloc(sizeof(*job));
+ 	*job = *pi; /* physical copy */
+ 	job->next = NULL;
+ 	job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
+ 	/* Cannot copy entire pi->cmds[] vector! This causes double frees */
+ 	for (i = 0; i < pi->num_cmds; i++) {
+ 		job->cmds[i].pid = pi->cmds[i].pid;
+ 		/* all other fields are not used and stay zero */
+ 	}
+ 	job->cmdtext = xstrdup(get_cmdtext(pi));
- 	debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
+ 	if (G_interactive_fd)
+ 		printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
+ 	/* Last command's pid goes to $! */
+ 	G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
+ 	G.last_jobid = job->jobid;
+ }
- #if ENABLE_HUSH_LOOPS
+ static void remove_bg_job(struct pipe *pi)
- 	/* Check syntax for "for" */
+ {
- 	for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
+ 	struct pipe *prev_pipe;
- 		if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
- 			continue;
+ 	if (pi == G.job_list) {
- 		/* current word is FOR or IN (BOLD in comments below) */
+ 		G.job_list = pi->next;
- 		if (cpipe->next == NULL) {
+ 	} else {
- 			syntax("malformed for");
+ 		prev_pipe = G.job_list;
- 			debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
+ 		while (prev_pipe->next != pi)
- 			return 1;
+ 			prev_pipe = prev_pipe->next;
- 		}
+ 		prev_pipe->next = pi->next;
- 		/* "FOR v; do ..." and "for v IN a b; do..." are ok */
- 		if (cpipe->next->res_word == RES_DO)
- 			continue;
- 		/* next word is not "do". It must be "in" then ("FOR v in ...") */
- 		if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
- 		 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
- 		) {
- 			syntax("malformed for");
- 			debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
- 			return 1;
- 		}
  	}
- #endif
+ 	if (G.job_list)
+ 		G.last_jobid = G.job_list->jobid;
+ 	else
+ 		G.last_jobid = 0;
+ }
- 	/* Past this point, all code paths should jump to ret: label
+ /* Remove a backgrounded job */
- 	 * in order to return, no direct "return" statements please.
+ static void delete_finished_bg_job(struct pipe *pi)
- 	 * This helps to ensure that no memory is leaked. */
+ {
+ 	remove_bg_job(pi);
+ 	pi->stopped_cmds = 0;
+ 	free_pipe(pi);
+ 	free(pi);
+ }
+ #endif /* JOB */
+ /* Check to see if any processes have exited -- if they
+  * have, figure out why and see if a job has completed */
+ static int checkjobs(struct pipe* fg_pipe)
+ {
+ 	int attributes;
+ 	int status;
  #if ENABLE_HUSH_JOB
- 	/* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
+ 	struct pipe *pi;
- 	 * We are saving state before entering outermost list ("while...done")
- 	 * so that ctrl-Z will correctly background _entire_ outermost list,
- 	 * not just a part of it (like "sleep 1 | exit 2") */
- 	if (++G.run_list_level == 1 && G.interactive_fd) {
- 		if (sigsetjmp(G.toplevel_jb, 1)) {
- 			/* ctrl-Z forked and we are parent; or ctrl-C.
- 			 * Sighandler has longjmped us here */
- 			signal(SIGINT, SIG_IGN);
- 			signal(SIGTSTP, SIG_IGN);
- 			/* Restore level (we can be coming from deep inside
- 			 * nested levels) */
- 			G.run_list_level = 1;
- #if ENABLE_FEATURE_SH_STANDALONE
- 			if (G.nofork_save.saved) { /* if save area is valid */
- 				debug_printf_jobs("exiting nofork early\n");
- 				restore_nofork_data(&G.nofork_save);
- 			}
- #endif
- 			if (G.ctrl_z_flag) {
- 				/* ctrl-Z has forked and stored pid of the child in pi->pid.
- 				 * Remember this child as background job */
- 				insert_bg_job(pi);
- 			} else {
- 				/* ctrl-C. We just stop doing whatever we were doing */
- 				bb_putchar('\n');
- 			}
- 			USE_HUSH_LOOPS(loop_top = NULL;)
- 			USE_HUSH_LOOPS(G.depth_of_loop = 0;)
- 			rcode = 0;
- 			goto ret;
- 		}
- 		/* ctrl-Z handler will store pid etc in pi */
- 		G.toplevel_list = pi;
- 		G.ctrl_z_flag = 0;
- #if ENABLE_FEATURE_SH_STANDALONE
- 		G.nofork_save.saved = 0; /* in case we will run a nofork later */
  #endif
- 		signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
+ 	pid_t childpid;
- 		signal(SIGINT, handler_ctrl_c);
+ 	int rcode = 0;
- 	}
- #endif /* JOB */
- 	/* Go through list of pipes, (maybe) executing them. */
+ 	debug_printf_jobs("checkjobs %p\n", fg_pipe);
- 	for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
- 		IF_HAS_KEYWORDS(rword = pi->res_word;)
- 		IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
- 		debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
- 				rword, cond_code, skip_more_for_this_rword);
- #if ENABLE_HUSH_LOOPS
- 		if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
- 		 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
- 		) {
- 			/* start of a loop: remember where loop starts */
- 			loop_top = pi;
- 			G.depth_of_loop++;
- 		}
- #endif
- 		if (rword == skip_more_for_this_rword && flag_skip) {
- 			if (pi->followup == PIPE_SEQ)
- 				flag_skip = 0;
- 			/* it is "<false> && CMD" or "<true> || CMD"
- 			 * and we should not execute CMD */
- 			continue;
- 		}
- 		flag_skip = 1;
- 		skip_more_for_this_rword = RES_XXXX;
- #if ENABLE_HUSH_IF
- 		if (cond_code) {
- 			if (rword == RES_THEN) {
- 				/* "if <false> THEN cmd": skip cmd */
- 				continue;
- 			}
- 		} else {
- 			if (rword == RES_ELSE || rword == RES_ELIF) {
- 				/* "if <true> then ... ELSE/ELIF cmd":
- 				 * skip cmd and all following ones */
- 				break;
- 			}
- 		}
- #endif
- #if ENABLE_HUSH_LOOPS
- 		if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
- 			if (!for_lcur) {
- 				/* first loop through for */
- 				static const char encoded_dollar_at[] ALIGN1 = {
+ 	attributes = WUNTRACED;
- 					SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
+ 	if (fg_pipe == NULL)
- 				}; /* encoded representation of "$@" */
+ 		attributes |= WNOHANG;
- 				static const char *const encoded_dollar_at_argv[] = {
- 					encoded_dollar_at, NULL
- 				}; /* argv list with one element: "$@" */
- 				char **vals;
- 				vals = (char**)encoded_dollar_at_argv;
+ 	errno = 0;
- 				if (pi->next->res_word == RES_IN) {
+ #if ENABLE_HUSH_FAST
- 					/* if no variable values after "in" we skip "for" */
+ 	if (G.handled_SIGCHLD == G.count_SIGCHLD) {
- 					if (!pi->next->cmds[0].argv)
+ //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
- 						break;
+ //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
- 					vals = pi->next->cmds[0].argv;
+ 		/* There was neither fork nor SIGCHLD since last waitpid */
- 				} /* else: "for var; do..." -> assume "$@" list */
+ 		/* Avoid doing waitpid syscall if possible */
- 				/* create list of variable values */
+ 		if (!G.we_have_children) {
- 				debug_print_strings("for_list made from", vals);
+ 			errno = ECHILD;
- 				for_list = expand_strvec_to_strvec(vals);
+ 			return -1;
- 				for_lcur = for_list;
- 				debug_print_strings("for_list", for_list);
- 				for_varname = pi->cmds[0].argv[0];
- 				pi->cmds[0].argv[0] = NULL;
- 			}
- 			free(pi->cmds[0].argv[0]);
- 			if (!*for_lcur) {
- 				/* "for" loop is over, clean up */
- 				free(for_list);
- 				for_list = NULL;
- 				for_lcur = NULL;
- 				pi->cmds[0].argv[0] = for_varname;
- 				break;
- 			}
- 			/* insert next value from for_lcur */
- //TODO: does it need escaping?
- 			pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
- 			pi->cmds[0].assignment_cnt = 1;
  		}
- 		if (rword == RES_IN) /* "for v IN list;..." - "in" has no cmds anyway */
+ 		if (fg_pipe == NULL) { /* is WNOHANG set? */
- 			continue;
+ 			/* We have children, but they did not exit
- 		if (rword == RES_DONE) {
+ 			 * or stop yet (we saw no SIGCHLD) */
- 			continue; /* "done" has no cmds too */
+ 			return 0;
  		}
+ 		/* else: !WNOHANG, waitpid will block, can't short-circuit */
+ 	}
  #endif
- #if ENABLE_HUSH_CASE
- 		if (rword == RES_CASE) {
- 			case_word = expand_strvec_to_string(pi->cmds->argv);
- 			continue;
- 		}
- 		if (rword == RES_MATCH) {
- 			char **argv;
- 			if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
+ /* Do we do this right?
- 				break;
+  * bash-3.00# sleep 20 | false
- 			/* all prev words didn't match, does this one match? */
+  * <ctrl-Z pressed>
- 			argv = pi->cmds->argv;
+  * [3]+  Stopped          sleep 20 | false
- 			while (*argv) {
+  * bash-3.00# echo $?
- 				char *pattern = expand_string_to_string(*argv);
+  * 1   <========== bg pipe is not fully done, but exitcode is already known!
- 				/* TODO: which FNM_xxx flags to use? */
+  * [hush 1.14.0: yes we do it right]
- 				cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
+  */
- 				free(pattern);
+  wait_more:
- 				if (cond_code == 0) { /* match! we will execute this branch */
+ 	while (1) {
- 					free(case_word); /* make future "word)" stop */
+ 		int i;
- 					case_word = NULL;
+ 		int dead;
- 					break;
- 				}
+ #if ENABLE_HUSH_FAST
- 				argv++;
+ 		i = G.count_SIGCHLD;
+ #endif
+ 		childpid = waitpid(-1, &status, attributes);
+ 		if (childpid <= 0) {
+ 			if (childpid && errno != ECHILD)
+ 				bb_perror_msg("waitpid");
+ #if ENABLE_HUSH_FAST
+ 			else { /* Until next SIGCHLD, waitpid's are useless */
+ 				G.we_have_children = (childpid == 0);
+ 				G.handled_SIGCHLD = i;
+ //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
  			}
- 			continue;
- 		}
- 		if (rword == RES_CASEI) { /* inside of a case branch */
- 			if (cond_code != 0)
- 				continue; /* not matched yet, skip this pipe */
- 		}
  #endif
- 		if (pi->num_cmds == 0)
+ 			break;
- 			continue;
+ 		}
+ 		dead = WIFEXITED(status) || WIFSIGNALED(status);
- 		/* After analyzing all keywords and conditions, we decided
+ #if DEBUG_JOBS
- 		 * to execute this pipe. NB: has to do checkjobs(NULL)
+ 		if (WIFSTOPPED(status))
- 		 * after run_pipe() to collect any background children,
+ 			debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
- 		 * even if list execution is to be stopped. */
+ 					childpid, WSTOPSIG(status), WEXITSTATUS(status));
- 		debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
+ 		if (WIFSIGNALED(status))
- 		{
+ 			debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
- 			int r;
+ 					childpid, WTERMSIG(status), WEXITSTATUS(status));
- #if ENABLE_HUSH_LOOPS
+ 		if (WIFEXITED(status))
- 			G.flag_break_continue = 0;
+ 			debug_printf_jobs("pid %d exited, exitcode %d\n",
+ 					childpid, WEXITSTATUS(status));
  #endif
- 			rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
+ 		/* Were we asked to wait for fg pipe? */
- 			if (r != -1) {
+ 		if (fg_pipe) {
- 				/* we only ran a builtin: rcode is already known
+ 			for (i = 0; i < fg_pipe->num_cmds; i++) {
- 				 * and we don't need to wait for anything. */
+ 				debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
- #if ENABLE_HUSH_LOOPS
+ 				if (fg_pipe->cmds[i].pid != childpid)
- 				/* was it "break" or "continue"? */
- 				if (G.flag_break_continue) {
- 					smallint fbc = G.flag_break_continue;
- 					/* we might fall into outer *loop*,
- 					 * don't want to break it too */
- 					if (loop_top) {
- 						G.depth_break_continue--;
- 						if (G.depth_break_continue == 0)
- 							G.flag_break_continue = 0;
- 						/* else: e.g. "continue 2" should *break* once, *then* continue */
- 					} /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
- 					if (G.depth_break_continue != 0 || fbc == BC_BREAK)
- 						goto check_jobs_and_break;
- 					/* "continue": simulate end of loop */
- 					rword = RES_DONE;
  					continue;
+ 				if (dead) {
+ 					fg_pipe->cmds[i].pid = 0;
+ 					fg_pipe->alive_cmds--;
+ 					if (i == fg_pipe->num_cmds - 1) {
+ 						/* last process gives overall exitstatus */
+ 						rcode = WEXITSTATUS(status);
+ 						/* bash prints killer signal's name for *last*
+ 						 * process in pipe (prints just newline for SIGINT).
+ 						 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
+ 						 */
+ 						if (WIFSIGNALED(status)) {
+ 							int sig = WTERMSIG(status);
+ 							printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
+ 							/* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
+ 							 * Maybe we need to use sig | 128? */
+ 							rcode = sig + 128;
+ 						}
+ 						IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
+ 					}
+ 				} else {
+ 					fg_pipe->cmds[i].is_stopped = 1;
+ 					fg_pipe->stopped_cmds++;
  				}
- #endif
+ 				debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
- 			} else if (pi->followup == PIPE_BG) {
+ 						fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
- 				/* what does bash do with attempts to background builtins? */
+ 				if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
- 				/* even bash 3.2 doesn't do that well with nested bg:
+ 					/* All processes in fg pipe have exited or stopped */
- 				 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
+ /* Note: *non-interactive* bash does not continue if all processes in fg pipe
- 				 * I'm NOT treating inner &'s as jobs */
+  * are stopped. Testcase: "cat | cat" in a script (not on command line!)
- #if ENABLE_HUSH_JOB
+  * and "killall -STOP cat" */
- 				if (G.run_list_level == 1)
+ 					if (G_interactive_fd) {
- 					insert_bg_job(pi);
- #endif
- 				rcode = 0; /* EXIT_SUCCESS */
- 			} else {
  #if ENABLE_HUSH_JOB
- 				if (G.run_list_level == 1 && G.interactive_fd) {
+ 						if (fg_pipe->alive_cmds)
- 					/* waits for completion, then fg's main shell */
+ 							insert_bg_job(fg_pipe);
- 					rcode = checkjobs_and_fg_shell(pi);
- 					debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
- 				} else
- #endif
- 				{ /* this one just waits for completion */
- 					rcode = checkjobs(pi);
- 					debug_printf_exec(": checkjobs returned %d\n", rcode);
- 				}
- 			}
- 		}
- 		debug_printf_exec(": setting last_return_code=%d\n", rcode);
- 		G.last_return_code = rcode;
- 		/* Analyze how result affects subsequent commands */
- #if ENABLE_HUSH_IF
- 		if (rword == RES_IF || rword == RES_ELIF)
- 			cond_code = rcode;
- #endif
- #if ENABLE_HUSH_LOOPS
- 		if (rword == RES_WHILE) {
- 			if (rcode) {
- 				rcode = 0; /* "while false; do...done" - exitcode 0 */
- 				goto check_jobs_and_break;
- 			}
- 		}
- 		if (rword == RES_UNTIL) {
- 			if (!rcode) {
-  check_jobs_and_break:
- 				checkjobs(NULL);
- 				break;
- 			}
- 		}
  #endif
- 		if ((rcode == 0 && pi->followup == PIPE_OR)
+ 						return rcode;
- 		 || (rcode != 0 && pi->followup == PIPE_AND)
+ 					}
- 		) {
+ 					if (!fg_pipe->alive_cmds)
- 			skip_more_for_this_rword = rword;
+ 						return rcode;
+ 				}
+ 				/* There are still running processes in the fg pipe */
+ 				goto wait_more; /* do waitpid again */
+ 			}
+ 			/* it wasnt fg_pipe, look for process in bg pipes */
  		}
- 		checkjobs(NULL);
- 	} /* for (pi) */
  #if ENABLE_HUSH_JOB
- 	if (G.ctrl_z_flag) {
+ 		/* We asked to wait for bg or orphaned children */
- 		/* ctrl-Z forked somewhere in the past, we are the child,
+ 		/* No need to remember exitcode in this case */
- 		 * and now we completed running the list. Exit. */
+ 		for (pi = G.job_list; pi; pi = pi->next) {
- //TODO: _exit?
+ 			for (i = 0; i < pi->num_cmds; i++) {
- 		exit(rcode);
+ 				if (pi->cmds[i].pid == childpid)
- 	}
+ 					goto found_pi_and_prognum;
-  ret:
- 	if (!--G.run_list_level && G.interactive_fd) {
- 		signal(SIGTSTP, SIG_IGN);
- 		signal(SIGINT, SIG_IGN);
- 	}
- #endif
- 	debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
- #if ENABLE_HUSH_LOOPS
- 	if (loop_top)
- 		G.depth_of_loop--;
- 	free(for_list);
- #endif
- #if ENABLE_HUSH_CASE
- 	free(case_word);
- #endif
- 	return rcode;
- }
- /* return code is the exit status of the pipe */
- static int free_pipe(struct pipe *pi, int indent)
- {
- 	char **p;
- 	struct command *command;
- 	struct redir_struct *r, *rnext;
- 	int a, i, ret_code = 0;
- 	if (pi->stopped_cmds > 0)
- 		return ret_code;
- 	debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
- 	for (i = 0; i < pi->num_cmds; i++) {
- 		command = &pi->cmds[i];
- 		debug_printf_clean("%s  command %d:\n", indenter(indent), i);
- 		if (command->argv) {
- 			for (a = 0, p = command->argv; *p; a++, p++) {
- 				debug_printf_clean("%s   argv[%d] = %s\n", indenter(indent), a, *p);
  			}
- 			free_strings(command->argv);
- 			command->argv = NULL;
- 		} else if (command->group) {
- 			debug_printf_clean("%s   begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
- 			ret_code = free_pipe_list(command->group, indent+3);
- 			debug_printf_clean("%s   end group\n", indenter(indent));
- 		} else {
- 			debug_printf_clean("%s   (nil)\n", indenter(indent));
  		}
- 		for (r = command->redirects; r; r = rnext) {
+ 		/* Happens when shell is used as init process (init=/bin/sh) */
- 			debug_printf_clean("%s   redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
+ 		debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
- 			if (r->dup == -1) {
+ 		continue; /* do waitpid again */
- 				/* guard against the case >$FOO, where foo is unset or blank */
- 				if (r->rd_filename) {
+  found_pi_and_prognum:
- 					debug_printf_clean(" %s\n", r->rd_filename);
+ 		if (dead) {
- 					free(r->rd_filename);
+ 			/* child exited */
- 					r->rd_filename = NULL;
+ 			pi->cmds[i].pid = 0;
- 				}
+ 			pi->alive_cmds--;
- 			} else {
+ 			if (!pi->alive_cmds) {
- 				debug_printf_clean("&%d\n", r->dup);
+ 				if (G_interactive_fd)
+ 					printf(JOB_STATUS_FORMAT, pi->jobid,
+ 							"Done", pi->cmdtext);
+ 				delete_finished_bg_job(pi);
  			}
- 			rnext = r->next;
+ 		} else {
- 			free(r);
+ 			/* child stopped */
+ 			pi->cmds[i].is_stopped = 1;
+ 			pi->stopped_cmds++;
  		}
- 		command->redirects = NULL;
- 	}
- 	free(pi->cmds);   /* children are an array, they get freed all at once */
- 	pi->cmds = NULL;
- #if ENABLE_HUSH_JOB
- 	free(pi->cmdtext);
- 	pi->cmdtext = NULL;
  #endif
- 	return ret_code;
+ 	} /* while (waitpid succeeds)... */
- }
- static int free_pipe_list(struct pipe *head, int indent)
- {
- 	int rcode = 0;   /* if list has no members */
- 	struct pipe *pi, *next;
- 	for (pi = head; pi; pi = next) {
- #if HAS_KEYWORDS
- 		debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
- #endif
- 		rcode = free_pipe(pi, indent);
- 		debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
- 		next = pi->next;
- 		/*pi->next = NULL;*/
- 		free(pi);
- 	}
  	return rcode;
  }
- /* Select which version we will use */
+ #if ENABLE_HUSH_JOB
- static int run_and_free_list(struct pipe *pi)
+ static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
  {
- 	int rcode = 0;
+ 	pid_t p;
- 	debug_printf_exec("run_and_free_list entered\n");
+ 	int rcode = checkjobs(fg_pipe);
- 	if (!G.fake_mode) {
+ 	if (G_saved_tty_pgrp) {
- 		debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
+ 		/* Job finished, move the shell to the foreground */
- 		rcode = run_list(pi);
+ 		p = getpgrp(); /* our process group id */
+ 		debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
+ 		tcsetpgrp(G_interactive_fd, p);
  	}
- 	/* free_pipe_list has the side effect of clearing memory.
- 	 * In the long run that function can be merged with run_list,
- 	 * but doing that now would hobble the debugging effort. */
- 	free_pipe_list(pi, /* indent: */ 0);
- 	debug_printf_exec("run_and_free_list return %d\n", rcode);
  	return rcode;
  }
+ #endif
+ /* Start all the jobs, but don't wait for anything to finish.
+  * See checkjobs().
+  *
+  * Return code is normally -1, when the caller has to wait for children
+  * to finish to determine the exit status of the pipe.  If the pipe
+  * is a simple builtin command, however, the action is done by the
+  * time run_pipe returns, and the exit code is provided as the
+  * return value.
+  *
+  * Returns -1 only if started some children. IOW: we have to
+  * mask out retvals of builtins etc with 0xff!
+  *
+  * The only case when we do not need to [v]fork is when the pipe
+  * is single, non-backgrounded, non-subshell command. Examples:
+  * cmd ; ...   { list } ; ...
+  * cmd && ...  { list } && ...
+  * cmd || ...  { list } || ...
+  * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
+  * or (if SH_STANDALONE) an applet, and we can run the { list }
+  * with run_list. If it isn't one of these, we fork and exec cmd.
+  *
+  * Cases when we must fork:
+  * non-single:   cmd | cmd
+  * backgrounded: cmd &     { list } &
+  * subshell:     ( list ) [&]
+  */
+ static NOINLINE int run_pipe(struct pipe *pi)
+ {
+ 	static const char *const null_ptr = NULL;
+ 	int i;
+ 	int nextin;
+ 	struct command *command;
+ 	char **argv_expanded;
+ 	char **argv;
+ 	char *p;
+ 	/* it is not always needed, but we aim to smaller code */
+ 	int squirrel[] = { -1, -1, -1 };
+ 	int rcode;
- /* expand_strvec_to_strvec() takes a list of strings, expands
+ 	debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
-  * all variable references within and returns a pointer to
+ 	debug_enter();
-  * a list of expanded strings, possibly with larger number
-  * of strings. (Think VAR="a b"; echo $VAR).
-  * This new list is allocated as a single malloc block.
-  * NULL-terminated list of char* pointers is at the beginning of it,
-  * followed by strings themself.
-  * Caller can deallocate entire list by single free(list). */
- /* Store given string, finalizing the word and starting new one whenever
+ 	IF_HUSH_JOB(pi->pgrp = -1;)
-  * we encounter IFS char(s). This is used for expanding variable values.
+ 	pi->stopped_cmds = 0;
-  * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
+ 	command = &(pi->cmds[0]);
- static int expand_on_ifs(o_string *output, int n, const char *str)
+ 	argv_expanded = NULL;
- {
- 	while (1) {
+ 	if (pi->num_cmds != 1
- 		int word_len = strcspn(str, G.ifs);
+ 	 || pi->followup == PIPE_BG
- 		if (word_len) {
+ 	 || command->cmd_type == CMD_SUBSHELL
- 			if (output->o_quote || !output->o_glob)
+ 	) {
- 				o_addQstr(output, str, word_len);
+ 		goto must_fork;
- 			else /* protect backslashes against globbing up :) */
- 				o_addstr_duplicate_backslash(output, str, word_len);
- 			str += word_len;
- 		}
- 		if (!*str)  /* EOL - do not finalize word */
- 			break;
- 		o_addchr(output, '\0');
- 		debug_print_list("expand_on_ifs", output, n);
- 		n = o_save_ptr(output, n);
- 		str += strspn(str, G.ifs); /* skip ifs chars */
  	}
- 	debug_print_list("expand_on_ifs[1]", output, n);
- 	return n;
- }
- /* Expand all variable references in given string, adding words to list[]
+ 	pi->alive_cmds = 1;
-  * at n, n+1,... positions. Return updated n (so that list[n] is next one
-  * to be filled). This routine is extremely tricky: has to deal with
-  * variables/parameters with whitespace, $* and $@, and constructs like
-  * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
- static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
- {
- 	/* or_mask is either 0 (normal case) or 0x80
- 	 * (expansion of right-hand side of assignment == 1-element expand.
- 	 * It will also do no globbing, and thus we must not backslash-quote!) */
- 	char first_ch, ored_ch;
+ 	debug_printf_exec(": group:%p argv:'%s'\n",
- 	int i;
+ 		command->group, command->argv ? command->argv[0] : "NONE");
- 	const char *val;
- 	char *p;
- 	ored_ch = 0;
+ 	if (command->group) {
+ #if ENABLE_HUSH_FUNCTIONS
+ 		if (command->cmd_type == CMD_FUNCDEF) {
+ 			/* "executing" func () { list } */
+ 			struct function *funcp;
+ 			funcp = new_function(command->argv[0]);
+ 			/* funcp->name is already set to argv[0] */
+ 			funcp->body = command->group;
+ # if !BB_MMU
+ 			funcp->body_as_string = command->group_as_string;
+ 			command->group_as_string = NULL;
+ # endif
+ 			command->group = NULL;
+ 			command->argv[0] = NULL;
+ 			debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
+ 			funcp->parent_cmd = command;
+ 			command->child_func = funcp;
- 	debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
+ 			debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
- 	debug_print_list("expand_vars_to_list", output, n);
+ 			debug_leave();
- 	n = o_save_ptr(output, n);
+ 			return EXIT_SUCCESS;
- 	debug_print_list("expand_vars_to_list[0]", output, n);
+ 		}
+ #endif
+ 		/* { list } */
+ 		debug_printf("non-subshell group\n");
+ 		rcode = 1; /* exitcode if redir failed */
+ 		if (setup_redirects(command, squirrel) == 0) {
+ 			debug_printf_exec(": run_list\n");
+ 			rcode = run_list(command->group) & 0xff;
+ 		}
+ 		restore_redirects(squirrel);
+ 		IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
+ 		debug_leave();
+ 		debug_printf_exec("run_pipe: return %d\n", rcode);
+ 		return rcode;
+ 	}
- 	while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
+ 	argv = command->argv ? command->argv : (char **) &null_ptr;
- #if ENABLE_HUSH_TICK
+ 	{
- 		o_string subst_result = NULL_O_STRING;
+ 		const struct built_in_command *x;
+ #if ENABLE_HUSH_FUNCTIONS
+ 		const struct function *funcp;
+ #else
+ 		enum { funcp = 0 };
  #endif
- 		o_addstr(output, arg, p - arg);
+ 		char **new_env = NULL;
- 		debug_print_list("expand_vars_to_list[1]", output, n);
+ 		struct variable *old_vars = NULL;
- 		arg = ++p;
- 		p = strchr(p, SPECIAL_VAR_SYMBOL);
- 		first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
+ 		if (argv[command->assignment_cnt] == NULL) {
- 		/* "$@" is special. Even if quoted, it can still
+ 			/* Assignments, but no command */
- 		 * expand to nothing (not even an empty string) */
+ 			/* Ensure redirects take effect. Try "a=t >file" */
- 		if ((first_ch & 0x7f) != '@')
+ 			rcode = setup_redirects(command, squirrel);
- 			ored_ch |= first_ch;
+ 			restore_redirects(squirrel);
- 		val = NULL;
+ 			/* Set shell variables */
- 		switch (first_ch & 0x7f) {
+ 			while (*argv) {
- 		/* Highest bit in first_ch indicates that var is double-quoted */
+ 				p = expand_string_to_string(*argv);
- 		case '$': /* pid */
+ 				debug_printf_exec("set shell var:'%s'->'%s'\n",
- 			val = utoa(G.root_pid);
+ 						*argv, p);
- 			break;
+ 				set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
- 		case '!': /* bg pid */
+ 				argv++;
- 			val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
- 			break;
- 		case '?': /* exitcode */
- 			val = utoa(G.last_return_code);
- 			break;
- 		case '#': /* argc */
- 			val = utoa(G.global_argc ? G.global_argc-1 : 0);
- 			break;
- 		case '*':
- 		case '@':
- 			i = 1;
- 			if (!G.global_argv[i])
- 				break;
- 			ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
- 			if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
- 				smallint sv = output->o_quote;
- 				/* unquoted var's contents should be globbed, so don't quote */
- 				output->o_quote = 0;
- 				while (G.global_argv[i]) {
- 					n = expand_on_ifs(output, n, G.global_argv[i]);
- 					debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
- 					if (G.global_argv[i++][0] && G.global_argv[i]) {
- 						/* this argv[] is not empty and not last:
- 						 * put terminating NUL, start new word */
- 						o_addchr(output, '\0');
- 						debug_print_list("expand_vars_to_list[2]", output, n);
- 						n = o_save_ptr(output, n);
- 						debug_print_list("expand_vars_to_list[3]", output, n);
- 					}
- 				}
- 				output->o_quote = sv;
- 			} else
- 			/* If or_mask is nonzero, we handle assignment 'a=....$@.....'
- 			 * and in this case should treat it like '$*' - see 'else...' below */
- 			if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
- 				while (1) {
- 					o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
- 					if (++i >= G.global_argc)
- 						break;
- 					o_addchr(output, '\0');
- 					debug_print_list("expand_vars_to_list[4]", output, n);
- 					n = o_save_ptr(output, n);
- 				}
- 			} else { /* quoted $*: add as one word */
- 				while (1) {
- 					o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
- 					if (!G.global_argv[++i])
- 						break;
- 					if (G.ifs[0])
- 						o_addchr(output, G.ifs[0]);
- 				}
  			}
- 			break;
+ 			/* Do we need to flag set_local_var() errors?
- 		case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
+ 			 * "assignment to readonly var" and "putenv error"
- 			/* "Empty variable", used to make "" etc to not disappear */
+ 			 */
- 			arg++;
+ 			IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
- 			ored_ch = 0x80;
+ 			debug_leave();
- 			break;
+ 			debug_printf_exec("run_pipe: return %d\n", rcode);
- #if ENABLE_HUSH_TICK
+ 			return rcode;
- 		case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
+ 		}
- 			struct in_str input;
- 			*p = '\0';
+ 		/* Expand the rest into (possibly) many strings each */
- 			arg++;
+ 		if (0) {}
- //TODO: can we just stuff it into "output" directly?
+ #if ENABLE_HUSH_BASH_COMPAT
- 			debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
+ 		else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
- 			setup_string_in_str(&input, arg);
+ 			argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
- 			process_command_subs(&subst_result, &input, NULL);
- 			debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
- 			val = subst_result.data;
- 			goto store_val;
  		}
  #endif
- 		default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
+ #ifdef CMD_SINGLEWORD_NOGLOB_COND
- 			*p = '\0';
+ 		else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
- 			arg[0] = first_ch & 0x7f;
+ 			argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
- 			if (isdigit(arg[0])) {
- 				i = xatoi_u(arg);
+ 		}
- 				if (i < G.global_argc)
- 					val = G.global_argv[i];
- 				/* else val remains NULL: $N with too big N */
- 			} else
- 				val = lookup_param(arg);
- 			arg[0] = first_ch;
- #if ENABLE_HUSH_TICK
-  store_val:
  #endif
- 			*p = SPECIAL_VAR_SYMBOL;
+ 		else {
- 			if (!(first_ch & 0x80)) { /* unquoted $VAR */
+ 			argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
- 				debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
+ 		}
- 				if (val) {
- 					/* unquoted var's contents should be globbed, so don't quote */
+ 		/* if someone gives us an empty string: `cmd with empty output` */
- 					smallint sv = output->o_quote;
+ 		if (!argv_expanded[0]) {
- 					output->o_quote = 0;
+ 			free(argv_expanded);
- 					n = expand_on_ifs(output, n, val);
+ 			debug_leave();
- 					val = NULL;
+ 			return G.last_exitcode;
- 					output->o_quote = sv;
+ 		}
+ 		x = find_builtin(argv_expanded[0]);
+ #if ENABLE_HUSH_FUNCTIONS
+ 		funcp = NULL;
+ 		if (!x)
+ 			funcp = find_function(argv_expanded[0]);
+ #endif
+ 		if (x || funcp) {
+ 			if (!funcp) {
+ 				if (x->function == builtin_exec && argv_expanded[1] == NULL) {
+ 					debug_printf("exec with redirects only\n");
+ 					rcode = setup_redirects(command, NULL);
+ 					goto clean_up_and_ret1;
  				}
- 			} else { /* quoted $VAR, val will be appended below */
- 				debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
  			}
+ 			/* setup_redirects acts on file descriptors, not FILEs.
+ 			 * This is perfect for work that comes after exec().
+ 			 * Is it really safe for inline use?  Experimentally,
+ 			 * things seem to work. */
+ 			rcode = setup_redirects(command, squirrel);
+ 			if (rcode == 0) {
+ 				new_env = expand_assignments(argv, command->assignment_cnt);
+ 				old_vars = set_vars_and_save_old(new_env);
+ 				if (!funcp) {
+ 					debug_printf_exec(": builtin '%s' '%s'...\n",
+ 						x->cmd, argv_expanded[1]);
+ 					rcode = x->function(argv_expanded) & 0xff;
+ 					fflush_all();
+ 				}
+ #if ENABLE_HUSH_FUNCTIONS
+ 				else {
+ # if ENABLE_HUSH_LOCAL
+ 					struct variable **sv;
+ 					sv = G.shadowed_vars_pp;
+ 					G.shadowed_vars_pp = &old_vars;
+ # endif
+ 					debug_printf_exec(": function '%s' '%s'...\n",
+ 						funcp->name, argv_expanded[1]);
+ 					rcode = run_function(funcp, argv_expanded) & 0xff;
+ # if ENABLE_HUSH_LOCAL
+ 					G.shadowed_vars_pp = sv;
+ # endif
+ 				}
+ #endif
+ 			}
+ #if ENABLE_FEATURE_SH_STANDALONE
+  clean_up_and_ret:
+ #endif
+ 			restore_redirects(squirrel);
+ 			unset_vars(new_env);
+ 			add_vars(old_vars);
+  clean_up_and_ret1:
+ 			free(argv_expanded);
+ 			IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
+ 			debug_leave();
+ 			debug_printf_exec("run_pipe return %d\n", rcode);
+ 			return rcode;
  		}
- 		if (val) {
- 			o_addQstr(output, val, strlen(val));
+ #if ENABLE_FEATURE_SH_STANDALONE
+ 		i = find_applet_by_name(argv_expanded[0]);
+ 		if (i >= 0 && APPLET_IS_NOFORK(i)) {
+ 			rcode = setup_redirects(command, squirrel);
+ 			if (rcode == 0) {
+ 				new_env = expand_assignments(argv, command->assignment_cnt);
+ 				old_vars = set_vars_and_save_old(new_env);
+ 				debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
+ 					argv_expanded[0], argv_expanded[1]);
+ 				rcode = run_nofork_applet(i, argv_expanded);
+ 			}
+ 			goto clean_up_and_ret;
  		}
+ #endif
+ 		/* It is neither builtin nor applet. We must fork. */
+ 	}
- #if ENABLE_HUSH_TICK
+  must_fork:
- 		o_free(&subst_result);
+ 	/* NB: argv_expanded may already be created, and that
+ 	 * might include `cmd` runs! Do not rerun it! We *must*
+ 	 * use argv_expanded if it's non-NULL */
+ 	/* Going to fork a child per each pipe member */
+ 	pi->alive_cmds = 0;
+ 	nextin = 0;
+ 	for (i = 0; i < pi->num_cmds; i++) {
+ 		struct fd_pair pipefds;
+ #if !BB_MMU
+ 		volatile nommu_save_t nommu_save;
+ 		nommu_save.new_env = NULL;
+ 		nommu_save.old_vars = NULL;
+ 		nommu_save.argv = NULL;
+ 		nommu_save.argv_from_re_execing = NULL;
  #endif
- 		arg = ++p;
+ 		command = &(pi->cmds[i]);
- 	} /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
+ 		if (command->argv) {
+ 			debug_printf_exec(": pipe member '%s' '%s'...\n",
+ 					command->argv[0], command->argv[1]);
+ 		} else {
+ 			debug_printf_exec(": pipe member with no argv\n");
+ 		}
- 	if (arg[0]) {
+ 		/* pipes are inserted between pairs of commands */
- 		debug_print_list("expand_vars_to_list[a]", output, n);
+ 		pipefds.rd = 0;
- 		/* this part is literal, and it was already pre-quoted
+ 		pipefds.wr = 1;
- 		 * if needed (much earlier), do not use o_addQstr here! */
+ 		if ((i + 1) < pi->num_cmds)
- 		o_addstr(output, arg, strlen(arg) + 1);
+ 			xpiped_pair(pipefds);
- 		debug_print_list("expand_vars_to_list[b]", output, n);
- 	} else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
- 	 && !(ored_ch & 0x80) /* and all vars were not quoted. */
- 	) {
- 		n--;
- 		/* allow to reuse list[n] later without re-growth */
- 		output->has_empty_slot = 1;
- 	} else {
- 		o_addchr(output, '\0');
- 	}
- 	return n;
- }
- static char **expand_variables(char **argv, int or_mask)
+ 		command->pid = BB_MMU ? fork() : vfork();
- {
+ 		if (!command->pid) { /* child */
- 	int n;
+ #if ENABLE_HUSH_JOB
- 	char **list;
+ 			disable_restore_tty_pgrp_on_exit();
- 	char **v;
+ 			CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
- 	o_string output = NULL_O_STRING;
- 	if (or_mask & 0x100) {
+ 			/* Every child adds itself to new process group
- 		output.o_quote = 1; /* protect against globbing for "$var" */
+ 			 * with pgid == pid_of_first_child_in_pipe */
- 		/* (unquoted $var will temporarily switch it off) */
+ 			if (G.run_list_level == 1 && G_interactive_fd) {
- 		output.o_glob = 1;
+ 				pid_t pgrp;
- 	}
+ 				pgrp = pi->pgrp;
+ 				if (pgrp < 0) /* true for 1st process only */
+ 					pgrp = getpid();
+ 				if (setpgid(0, pgrp) == 0
+ 				 && pi->followup != PIPE_BG
+ 				 && G_saved_tty_pgrp /* we have ctty */
+ 				) {
+ 					/* We do it in *every* child, not just first,
+ 					 * to avoid races */
+ 					tcsetpgrp(G_interactive_fd, pgrp);
+ 				}
+ 			}
+ #endif
+ 			if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
+ 				/* 1st cmd in backgrounded pipe
+ 				 * should have its stdin /dev/null'ed */
+ 				close(0);
+ 				if (open(bb_dev_null, O_RDONLY))
+ 					xopen("/", O_RDONLY);
+ 			} else {
+ 				xmove_fd(nextin, 0);
+ 			}
+ 			xmove_fd(pipefds.wr, 1);
+ 			if (pipefds.rd > 1)
+ 				close(pipefds.rd);
+ 			/* Like bash, explicit redirects override pipes,
+ 			 * and the pipe fd is available for dup'ing. */
+ 			if (setup_redirects(command, NULL))
+ 				_exit(1);
- 	n = 0;
+ 			/* Restore default handlers just prior to exec */
- 	v = argv;
+ 			/*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
- 	while (*v) {
- 		n = expand_vars_to_list(&output, n, *v, (char)or_mask);
+ 			/* Stores to nommu_save list of env vars putenv'ed
- 		v++;
+ 			 * (NOMMU, on MMU we don't need that) */
+ 			/* cast away volatility... */
+ 			pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
+ 			/* pseudo_exec() does not return */
+ 		}
+ 		/* parent or error */
+ #if ENABLE_HUSH_FAST
+ 		G.count_SIGCHLD++;
+ //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
+ #endif
+ 		enable_restore_tty_pgrp_on_exit();
+ #if !BB_MMU
+ 		/* Clean up after vforked child */
+ 		free(nommu_save.argv);
+ 		free(nommu_save.argv_from_re_execing);
+ 		unset_vars(nommu_save.new_env);
+ 		add_vars(nommu_save.old_vars);
+ #endif
+ 		free(argv_expanded);
+ 		argv_expanded = NULL;
+ 		if (command->pid < 0) { /* [v]fork failed */
+ 			/* Clearly indicate, was it fork or vfork */
+ 			bb_perror_msg(BB_MMU ? "fork" : "vfork");
+ 		} else {
+ 			pi->alive_cmds++;
+ #if ENABLE_HUSH_JOB
+ 			/* Second and next children need to know pid of first one */
+ 			if (pi->pgrp < 0)
+ 				pi->pgrp = command->pid;
+ #endif
+ 		}
+ 		if (i)
+ 			close(nextin);
+ 		if ((i + 1) < pi->num_cmds)
+ 			close(pipefds.wr);
+ 		/* Pass read (output) pipe end to next iteration */
+ 		nextin = pipefds.rd;
  	}
- 	debug_print_list("expand_variables", &output, n);
- 	/* output.data (malloced in one block) gets returned in "list" */
+ 	if (!pi->alive_cmds) {
- 	list = o_finalize_list(&output, n);
+ 		debug_leave();
- 	debug_print_strings("expand_variables[1]", list);
+ 		debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
- 	return list;
+ 		return 1;
- }
+ 	}
- static char **expand_strvec_to_strvec(char **argv)
+ 	debug_leave();
- {
+ 	debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
- 	return expand_variables(argv, 0x100);
+ 	return -1;
  }
- /* Used for expansion of right hand of assignments */
+ #ifndef debug_print_tree
- /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
+ static void debug_print_tree(struct pipe *pi, int lvl)
-  * "v=/bin/c*" */
- static char *expand_string_to_string(const char *str)
  {
- 	char *argv[2], **list;
+ 	static const char *const PIPE[] = {
+ 		[PIPE_SEQ] = "SEQ",
+ 		[PIPE_AND] = "AND",
+ 		[PIPE_OR ] = "OR" ,
+ 		[PIPE_BG ] = "BG" ,
+ 	};
+ 	static const char *RES[] = {
+ 		[RES_NONE ] = "NONE" ,
+ # if ENABLE_HUSH_IF
+ 		[RES_IF   ] = "IF"   ,
+ 		[RES_THEN ] = "THEN" ,
+ 		[RES_ELIF ] = "ELIF" ,
+ 		[RES_ELSE ] = "ELSE" ,
+ 		[RES_FI   ] = "FI"   ,
+ # endif
+ # if ENABLE_HUSH_LOOPS
+ 		[RES_FOR  ] = "FOR"  ,
+ 		[RES_WHILE] = "WHILE",
+ 		[RES_UNTIL] = "UNTIL",
+ 		[RES_DO   ] = "DO"   ,
+ 		[RES_DONE ] = "DONE" ,
+ # endif
+ # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
+ 		[RES_IN   ] = "IN"   ,
+ # endif
+ # if ENABLE_HUSH_CASE
+ 		[RES_CASE ] = "CASE" ,
+ 		[RES_CASE_IN ] = "CASE_IN" ,
+ 		[RES_MATCH] = "MATCH",
+ 		[RES_CASE_BODY] = "CASE_BODY",
+ 		[RES_ESAC ] = "ESAC" ,
+ # endif
+ 		[RES_XXXX ] = "XXXX" ,
+ 		[RES_SNTX ] = "SNTX" ,
+ 	};
+ 	static const char *const CMDTYPE[] = {
+ 		"{}",
+ 		"()",
+ 		"[noglob]",
+ # if ENABLE_HUSH_FUNCTIONS
+ 		"func()",
+ # endif
+ 	};
- 	argv[0] = (char*)str;
+ 	int pin, prn;
- 	argv[1] = NULL;
- 	list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
- 	if (HUSH_DEBUG)
- 		if (!list[0] || list[1])
- 			bb_error_msg_and_die("BUG in varexp2");
- 	/* actually, just move string 2*sizeof(char*) bytes back */
- 	strcpy((char*)list, list[0]);
- 	debug_printf_expand("string_to_string='%s'\n", (char*)list);
- 	return (char*)list;
- }
- /* Used for "eval" builtin */
+ 	pin = 0;
- static char* expand_strvec_to_string(char **argv)
+ 	while (pi) {
- {
+ 		fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
- 	char **list;
+ 				pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
+ 		prn = 0;
+ 		while (prn < pi->num_cmds) {
+ 			struct command *command = &pi->cmds[prn];
+ 			char **argv = command->argv;
- 	list = expand_variables(argv, 0x80);
+ 			fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
- 	/* Convert all NULs to spaces */
+ 					lvl*2, "", prn,
- 	if (list[0]) {
+ 					command->assignment_cnt);
- 		int n = 1;
+ 			if (command->group) {
- 		while (list[n]) {
+ 				fprintf(stderr, " group %s: (argv=%p)%s%s\n",
- 			if (HUSH_DEBUG)
+ 						CMDTYPE[command->cmd_type],
- 				if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
+ 						argv
- 					bb_error_msg_and_die("BUG in varexp3");
+ #if !BB_MMU
- 			list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
+ 						, " group_as_string:", command->group_as_string
- 			n++;
+ #else
+ 						, "", ""
+ #endif
+ 				);
+ 				debug_print_tree(command->group, lvl+1);
+ 				prn++;
+ 				continue;
+ 			}
+ 			if (argv) while (*argv) {
+ 				fprintf(stderr, " '%s'", *argv);
+ 				argv++;
+ 			}
+ 			fprintf(stderr, "\n");
+ 			prn++;
  		}
+ 		pi = pi->next;
+ 		pin++;
  	}
- 	strcpy((char*)list, list[0]);
- 	debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
- 	return (char*)list;
  }
+ #endif /* debug_print_tree */
+ /* NB: called by pseudo_exec, and therefore must not modify any
- /* Used to get/check local shell variables */
+  * global data until exec/_exit (we can be a child after vfork!) */
- static struct variable *get_local_var(const char *name)
+ static int run_list(struct pipe *pi)
  {
- 	struct variable *cur;
+ #if ENABLE_HUSH_CASE
- 	int len;
+ 	char *case_word = NULL;
+ #endif
+ #if ENABLE_HUSH_LOOPS
+ 	struct pipe *loop_top = NULL;
+ 	char **for_lcur = NULL;
+ 	char **for_list = NULL;
+ #endif
+ 	smallint last_followup;
+ 	smalluint rcode;
+ #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
+ 	smalluint cond_code = 0;
+ #else
+ 	enum { cond_code = 0 };
+ #endif
+ #if HAS_KEYWORDS
+ 	smallint rword; /* enum reserved_style */
+ 	smallint last_rword; /* ditto */
+ #endif
- 	if (!name)
+ 	debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
- 		return NULL;
+ 	debug_enter();
- 	len = strlen(name);
- 	for (cur = G.top_var; cur; cur = cur->next) {
+ #if ENABLE_HUSH_LOOPS
- 		if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
+ 	/* Check syntax for "for" */
- 			return cur;
+ 	for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
+ 		if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
+ 			continue;
+ 		/* current word is FOR or IN (BOLD in comments below) */
+ 		if (cpipe->next == NULL) {
+ 			syntax_error("malformed for");
+ 			debug_leave();
+ 			debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
+ 			return 1;
+ 		}
+ 		/* "FOR v; do ..." and "for v IN a b; do..." are ok */
+ 		if (cpipe->next->res_word == RES_DO)
+ 			continue;
+ 		/* next word is not "do". It must be "in" then ("FOR v in ...") */
+ 		if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
+ 		 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
+ 		) {
+ 			syntax_error("malformed for");
+ 			debug_leave();
+ 			debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
+ 			return 1;
+ 		}
  	}
- 	return NULL;
+ #endif
- }
- /* str holds "NAME=VAL" and is expected to be malloced.
+ 	/* Past this point, all code paths should jump to ret: label
-  * We take ownership of it. */
+ 	 * in order to return, no direct "return" statements please.
- static int set_local_var(char *str, int flg_export)
+ 	 * This helps to ensure that no memory is leaked. */
- {
- 	struct variable *cur;
- 	char *value;
- 	int name_len;
- 	value = strchr(str, '=');
+ #if ENABLE_HUSH_JOB
- 	if (!value) { /* not expected to ever happen? */
+ 	G.run_list_level++;
- 		free(str);
+ #endif
- 		return -1;
- 	}
- 	name_len = value - str + 1; /* including '=' */
+ #if HAS_KEYWORDS
- 	cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
+ 	rword = RES_NONE;
- 	while (1) {
+ 	last_rword = RES_XXXX;
- 		if (strncmp(cur->varstr, str, name_len) != 0) {
+ #endif
- 			if (!cur->next) {
+ 	last_followup = PIPE_SEQ;
- 				/* Bail out. Note that now cur points
+ 	rcode = G.last_exitcode;
- 				 * to last var in linked list */
+ 	/* Go through list of pipes, (maybe) executing them. */
+ 	for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
+ 		if (G.flag_SIGINT)
+ 			break;
+ 		IF_HAS_KEYWORDS(rword = pi->res_word;)
+ 		debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
+ 				rword, cond_code, last_rword);
+ #if ENABLE_HUSH_LOOPS
+ 		if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
+ 		 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
+ 		) {
+ 			/* start of a loop: remember where loop starts */
+ 			loop_top = pi;
+ 			G.depth_of_loop++;
+ 		}
+ #endif
+ 		/* Still in the same "if...", "then..." or "do..." branch? */
+ 		if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
+ 			if ((rcode == 0 && last_followup == PIPE_OR)
+ 			 || (rcode != 0 && last_followup == PIPE_AND)
+ 			) {
+ 				/* It is "<true> || CMD" or "<false> && CMD"
+ 				 * and we should not execute CMD */
+ 				debug_printf_exec("skipped cmd because of || or &&\n");
+ 				last_followup = pi->followup;
+ 				continue;
+ 			}
+ 		}
+ 		last_followup = pi->followup;
+ 		IF_HAS_KEYWORDS(last_rword = rword;)
+ #if ENABLE_HUSH_IF
+ 		if (cond_code) {
+ 			if (rword == RES_THEN) {
+ 				/* if false; then ... fi has exitcode 0! */
+ 				G.last_exitcode = rcode = EXIT_SUCCESS;
+ 				/* "if <false> THEN cmd": skip cmd */
+ 				continue;
+ 			}
+ 		} else {
+ 			if (rword == RES_ELSE || rword == RES_ELIF) {
+ 				/* "if <true> then ... ELSE/ELIF cmd":
+ 				 * skip cmd and all following ones */
+ 				break;
+ 			}
+ 		}
+ #endif
+ #if ENABLE_HUSH_LOOPS
+ 		if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
+ 			if (!for_lcur) {
+ 				/* first loop through for */
+ 				static const char encoded_dollar_at[] ALIGN1 = {
+ 					SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
+ 				}; /* encoded representation of "$@" */
+ 				static const char *const encoded_dollar_at_argv[] = {
+ 					encoded_dollar_at, NULL
+ 				}; /* argv list with one element: "$@" */
+ 				char **vals;
+ 				vals = (char**)encoded_dollar_at_argv;
+ 				if (pi->next->res_word == RES_IN) {
+ 					/* if no variable values after "in" we skip "for" */
+ 					if (!pi->next->cmds[0].argv) {
+ 						G.last_exitcode = rcode = EXIT_SUCCESS;
+ 						debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
+ 						break;
+ 					}
+ 					vals = pi->next->cmds[0].argv;
+ 				} /* else: "for var; do..." -> assume "$@" list */
+ 				/* create list of variable values */
+ 				debug_print_strings("for_list made from", vals);
+ 				for_list = expand_strvec_to_strvec(vals);
+ 				for_lcur = for_list;
+ 				debug_print_strings("for_list", for_list);
+ 			}
+ 			if (!*for_lcur) {
+ 				/* "for" loop is over, clean up */
+ 				free(for_list);
+ 				for_list = NULL;
+ 				for_lcur = NULL;
  				break;
  			}
- 			cur = cur->next;
+ 			/* Insert next value from for_lcur */
+ 			/* note: *for_lcur already has quotes removed, $var expanded, etc */
+ 			set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
  			continue;
  		}
- 		/* We found an existing var with this name */
+ 		if (rword == RES_IN) {
- 		*value = '\0';
+ 			continue; /* "for v IN list;..." - "in" has no cmds anyway */
- 		if (cur->flg_read_only) {
- 			bb_error_msg("%s: readonly variable", str);
- 			free(str);
- 			return -1;
  		}
- 		debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
+ 		if (rword == RES_DONE) {
- 		unsetenv(str); /* just in case */
+ 			continue; /* "done" has no cmds too */
- 		*value = '=';
- 		if (strcmp(cur->varstr, str) == 0) {
-  free_and_exp:
- 			free(str);
- 			goto exp;
  		}
- 		if (cur->max_len >= strlen(str)) {
+ #endif
- 			/* This one is from startup env, reuse space */
+ #if ENABLE_HUSH_CASE
- 			strcpy(cur->varstr, str);
+ 		if (rword == RES_CASE) {
- 			goto free_and_exp;
+ 			case_word = expand_strvec_to_string(pi->cmds->argv);
- 		}
+ 			continue;
- 		/* max_len == 0 signifies "malloced" var, which we can
+ 		}
- 		 * (and has to) free */
+ 		if (rword == RES_MATCH) {
- 		if (!cur->max_len)
+ 			char **argv;
- 			free(cur->varstr);
- 		cur->max_len = 0;
+ 			if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
- 		goto set_str_and_exp;
+ 				break;
- 	}
+ 			/* all prev words didn't match, does this one match? */
+ 			argv = pi->cmds->argv;
+ 			while (*argv) {
+ 				char *pattern = expand_string_to_string(*argv);
+ 				/* TODO: which FNM_xxx flags to use? */
+ 				cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
+ 				free(pattern);
+ 				if (cond_code == 0) { /* match! we will execute this branch */
+ 					free(case_word); /* make future "word)" stop */
+ 					case_word = NULL;
+ 					break;
+ 				}
+ 				argv++;
+ 			}
+ 			continue;
+ 		}
+ 		if (rword == RES_CASE_BODY) { /* inside of a case branch */
+ 			if (cond_code != 0)
+ 				continue; /* not matched yet, skip this pipe */
+ 		}
+ #endif
+ 		/* Just pressing <enter> in shell should check for jobs.
+ 		 * OTOH, in non-interactive shell this is useless
+ 		 * and only leads to extra job checks */
+ 		if (pi->num_cmds == 0) {
+ 			if (G_interactive_fd)
+ 				goto check_jobs_and_continue;
+ 			continue;
+ 		}
+ 		/* After analyzing all keywords and conditions, we decided
+ 		 * to execute this pipe. NB: have to do checkjobs(NULL)
+ 		 * after run_pipe to collect any background children,
+ 		 * even if list execution is to be stopped. */
+ 		debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
+ 		{
+ 			int r;
+ #if ENABLE_HUSH_LOOPS
+ 			G.flag_break_continue = 0;
+ #endif
+ 			rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
+ 			if (r != -1) {
+ 				/* We ran a builtin, function, or group.
+ 				 * rcode is already known
+ 				 * and we don't need to wait for anything. */
+ 				G.last_exitcode = rcode;
+ 				debug_printf_exec(": builtin/func exitcode %d\n", rcode);
+ 				check_and_run_traps(0);
+ #if ENABLE_HUSH_LOOPS
+ 				/* Was it "break" or "continue"? */
+ 				if (G.flag_break_continue) {
+ 					smallint fbc = G.flag_break_continue;
+ 					/* We might fall into outer *loop*,
+ 					 * don't want to break it too */
+ 					if (loop_top) {
+ 						G.depth_break_continue--;
+ 						if (G.depth_break_continue == 0)
+ 							G.flag_break_continue = 0;
+ 						/* else: e.g. "continue 2" should *break* once, *then* continue */
+ 					} /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
+ 					if (G.depth_break_continue != 0 || fbc == BC_BREAK)
+ 						goto check_jobs_and_break;
+ 					/* "continue": simulate end of loop */
+ 					rword = RES_DONE;
+ 					continue;
+ 				}
+ #endif
+ #if ENABLE_HUSH_FUNCTIONS
+ 				if (G.flag_return_in_progress == 1) {
+ 					/* same as "goto check_jobs_and_break" */
+ 					checkjobs(NULL);
+ 					break;
+ 				}
+ #endif
+ 			} else if (pi->followup == PIPE_BG) {
+ 				/* What does bash do with attempts to background builtins? */
+ 				/* even bash 3.2 doesn't do that well with nested bg:
+ 				 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
+ 				 * I'm NOT treating inner &'s as jobs */
+ 				check_and_run_traps(0);
+ #if ENABLE_HUSH_JOB
+ 				if (G.run_list_level == 1)
+ 					insert_bg_job(pi);
+ #endif
+ 				G.last_exitcode = rcode = EXIT_SUCCESS;
+ 				debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
+ 			} else {
+ #if ENABLE_HUSH_JOB
+ 				if (G.run_list_level == 1 && G_interactive_fd) {
+ 					/* Waits for completion, then fg's main shell */
+ 					rcode = checkjobs_and_fg_shell(pi);
+ 					debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
+ 					check_and_run_traps(0);
+ 				} else
+ #endif
+ 				{ /* This one just waits for completion */
+ 					rcode = checkjobs(pi);
+ 					debug_printf_exec(": checkjobs exitcode %d\n", rcode);
+ 					check_and_run_traps(0);
+ 				}
+ 				G.last_exitcode = rcode;
+ 			}
+ 		}
+ 		/* Analyze how result affects subsequent commands */
+ #if ENABLE_HUSH_IF
+ 		if (rword == RES_IF || rword == RES_ELIF)
+ 			cond_code = rcode;
+ #endif
+ #if ENABLE_HUSH_LOOPS
+ 		/* Beware of "while false; true; do ..."! */
+ 		if (pi->next && pi->next->res_word == RES_DO) {
+ 			if (rword == RES_WHILE) {
+ 				if (rcode) {
+ 					/* "while false; do...done" - exitcode 0 */
+ 					G.last_exitcode = rcode = EXIT_SUCCESS;
+ 					debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
+ 					goto check_jobs_and_break;
+ 				}
+ 			}
+ 			if (rword == RES_UNTIL) {
+ 				if (!rcode) {
+ 					debug_printf_exec(": until expr is true: breaking\n");
+  check_jobs_and_break:
+ 					checkjobs(NULL);
+ 					break;
+ 				}
+ 			}
+ 		}
+ #endif
+  check_jobs_and_continue:
+ 		checkjobs(NULL);
+ 	} /* for (pi) */
- 	/* Not found - create next variable struct */
+ #if ENABLE_HUSH_JOB
- 	cur->next = xzalloc(sizeof(*cur));
+ 	G.run_list_level--;
- 	cur = cur->next;
+ #endif
+ #if ENABLE_HUSH_LOOPS
+ 	if (loop_top)
+ 		G.depth_of_loop--;
+ 	free(for_list);
+ #endif
+ #if ENABLE_HUSH_CASE
+ 	free(case_word);
+ #endif
+ 	debug_leave();
+ 	debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
+ 	return rcode;
+ }
-  set_str_and_exp:
+ /* Select which version we will use */
- 	cur->varstr = str;
+ static int run_and_free_list(struct pipe *pi)
-  exp:
+ {
- 	if (flg_export)
+ 	int rcode = 0;
- 		cur->flg_export = 1;
+ 	debug_printf_exec("run_and_free_list entered\n");
- 	if (cur->flg_export) {
+ 	if (!G.fake_mode) {
- 		debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
+ 		debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
- 		return putenv(cur->varstr);
+ 		rcode = run_list(pi);
  	}
- 	return 0;
+ 	/* free_pipe_list has the side effect of clearing memory.
+ 	 * In the long run that function can be merged with run_list,
+ 	 * but doing that now would hobble the debugging effort. */
+ 	free_pipe_list(pi);
+ 	debug_printf_exec("run_and_free_list return %d\n", rcode);
+ 	return rcode;
  }
- static void unset_local_var(const char *name)
- {
- 	struct variable *cur;
- 	struct variable *prev = prev; /* for gcc */
- 	int name_len;
- 	if (!name)
+ static struct pipe *new_pipe(void)
- 		return;
+ {
- 	name_len = strlen(name);
+ 	struct pipe *pi;
- 	cur = G.top_var;
+ 	pi = xzalloc(sizeof(struct pipe));
- 	while (cur) {
+ 	/*pi->followup = 0; - deliberately invalid value */
- 		if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
+ 	/*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
- 			if (cur->flg_read_only) {
+ 	return pi;
- 				bb_error_msg("%s: readonly variable", name);
- 				return;
- 			}
- 			/* prev is ok to use here because 1st variable, HUSH_VERSION,
- 			 * is ro, and we cannot reach this code on the 1st pass */
- 			prev->next = cur->next;
- 			debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
- 			unsetenv(cur->varstr);
- 			if (!cur->max_len)
- 				free(cur->varstr);
- 			free(cur);
- 			return;
- 		}
- 		prev = cur;
- 		cur = cur->next;
- 	}
  }
- /* The src parameter allows us to peek forward to a possible &n syntax
+ /* Command (member of a pipe) is complete, or we start a new pipe
-  * for file descriptor duplication, e.g., "2>&1".
+  * if ctx->command is NULL.
-  * Return code is 0 normally, 1 if a syntax error is detected in src.
+  * No errors possible here.
-  * Resource errors (in xmalloc) cause the process to exit */
+  */
- static int setup_redirect(struct parse_context *ctx, int fd, redir_type style,
+ static int done_command(struct parse_context *ctx)
- 	struct in_str *input)
  {
+ 	/* The command is really already in the pipe structure, so
+ 	 * advance the pipe counter and make a new, null command. */
+ 	struct pipe *pi = ctx->pipe;
  	struct command *command = ctx->command;
- 	struct redir_struct *redir = command->redirects;
- 	struct redir_struct *last_redir = NULL;
- 	/* Create a new redir_struct and drop it onto the end of the linked list */
+ 	if (command) {
- 	while (redir) {
+ 		if (IS_NULL_CMD(command)) {
- 		last_redir = redir;
+ 			debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
- 		redir = redir->next;
+ 			goto clear_and_ret;
- 	}
+ 		}
- 	redir = xzalloc(sizeof(struct redir_struct));
+ 		pi->num_cmds++;
- 	/* redir->next = NULL; */
+ 		debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
- 	/* redir->rd_filename = NULL; */
+ 		//debug_print_tree(ctx->list_head, 20);
- 	if (last_redir) {
- 		last_redir->next = redir;
  	} else {
- 		command->redirects = redir;
+ 		debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
  	}
- 	redir->rd_type = style;
+ 	/* Only real trickiness here is that the uncommitted
- 	redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
+ 	 * command structure is not counted in pi->num_cmds. */
+ 	pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
- 	debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
+ 	ctx->command = command = &pi->cmds[pi->num_cmds];
+  clear_and_ret:
- 	/* Check for a '2>&1' type redirect */
+ 	memset(command, 0, sizeof(*command));
- 	redir->dup = redirect_dup_num(input);
+ 	return pi->num_cmds; /* used only for 0/nonzero check */
- 	if (redir->dup == -2)
- 		return 1;  /* syntax error */
- 	if (redir->dup != -1) {
- 		/* Erik had a check here that the file descriptor in question
- 		 * is legit; I postpone that to "run time"
- 		 * A "-" representation of "close me" shows up as a -3 here */
- 		debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
- 	} else {
- 		/* We do _not_ try to open the file that src points to,
- 		 * since we need to return and let src be expanded first.
- 		 * Set ctx->pending_redirect, so we know what to do at the
- 		 * end of the next parsed word. */
- 		ctx->pending_redirect = redir;
- 	}
- 	return 0;
  }
- static struct pipe *new_pipe(void)
+ static void done_pipe(struct parse_context *ctx, pipe_style type)
  {
- 	struct pipe *pi;
+ 	int not_null;
- 	pi = xzalloc(sizeof(struct pipe));
- 	/*pi->followup = 0; - deliberately invalid value */
+ 	debug_printf_parse("done_pipe entered, followup %d\n", type);
- 	/*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
+ 	/* Close previous command */
- 	return pi;
+ 	not_null = done_command(ctx);
+ 	ctx->pipe->followup = type;
+ #if HAS_KEYWORDS
+ 	ctx->pipe->pi_inverted = ctx->ctx_inverted;
+ 	ctx->ctx_inverted = 0;
+ 	ctx->pipe->res_word = ctx->ctx_res_w;
+ #endif
+ 	/* Without this check, even just <enter> on command line generates
+ 	 * tree of three NOPs (!). Which is harmless but annoying.
+ 	 * IOW: it is safe to do it unconditionally. */
+ 	if (not_null
+ #if ENABLE_HUSH_IF
+ 	 || ctx->ctx_res_w == RES_FI
+ #endif
+ #if ENABLE_HUSH_LOOPS
+ 	 || ctx->ctx_res_w == RES_DONE
+ 	 || ctx->ctx_res_w == RES_FOR
+ 	 || ctx->ctx_res_w == RES_IN
+ #endif
+ #if ENABLE_HUSH_CASE
+ 	 || ctx->ctx_res_w == RES_ESAC
+ #endif
+ 	) {
+ 		struct pipe *new_p;
+ 		debug_printf_parse("done_pipe: adding new pipe: "
+ 				"not_null:%d ctx->ctx_res_w:%d\n",
+ 				not_null, ctx->ctx_res_w);
+ 		new_p = new_pipe();
+ 		ctx->pipe->next = new_p;
+ 		ctx->pipe = new_p;
+ 		/* RES_THEN, RES_DO etc are "sticky" -
+ 		 * they remain set for pipes inside if/while.
+ 		 * This is used to control execution.
+ 		 * RES_FOR and RES_IN are NOT sticky (needed to support
+ 		 * cases where variable or value happens to match a keyword):
+ 		 */
+ #if ENABLE_HUSH_LOOPS
+ 		if (ctx->ctx_res_w == RES_FOR
+ 		 || ctx->ctx_res_w == RES_IN)
+ 			ctx->ctx_res_w = RES_NONE;
+ #endif
+ #if ENABLE_HUSH_CASE
+ 		if (ctx->ctx_res_w == RES_MATCH)
+ 			ctx->ctx_res_w = RES_CASE_BODY;
+ 		if (ctx->ctx_res_w == RES_CASE)
+ 			ctx->ctx_res_w = RES_CASE_IN;
+ #endif
+ 		ctx->command = NULL; /* trick done_command below */
+ 		/* Create the memory for command, roughly:
+ 		 * ctx->pipe->cmds = new struct command;
+ 		 * ctx->command = &ctx->pipe->cmds[0];
+ 		 */
+ 		done_command(ctx);
+ 		//debug_print_tree(ctx->list_head, 10);
+ 	}
+ 	debug_printf_parse("done_pipe return\n");
  }
  static void initialize_context(struct parse_context *ctx)
-Line 3014 
 static void initialize_context(struct pa
+Line 4910 
 static void initialize_context(struct pa
  /* If a reserved word is found and processed, parse context is modified
   * and 1 is returned.
-  * Handles if, then, elif, else, fi, for, while, until, do, done.
-  * case, function, and select are obnoxious, save those for later.
   */
  #if HAS_KEYWORDS
  struct reserved_combo {
-Line 3026 
 struct reserved_combo {
+Line 4920 
 struct reserved_combo {
  };
  enum {
  	FLAG_END   = (1 << RES_NONE ),
- #if ENABLE_HUSH_IF
+ # if ENABLE_HUSH_IF
  	FLAG_IF    = (1 << RES_IF   ),
  	FLAG_THEN  = (1 << RES_THEN ),
  	FLAG_ELIF  = (1 << RES_ELIF ),
  	FLAG_ELSE  = (1 << RES_ELSE ),
  	FLAG_FI    = (1 << RES_FI   ),
- #endif
+ # endif
- #if ENABLE_HUSH_LOOPS
+ # if ENABLE_HUSH_LOOPS
  	FLAG_FOR   = (1 << RES_FOR  ),
  	FLAG_WHILE = (1 << RES_WHILE),
  	FLAG_UNTIL = (1 << RES_UNTIL),
  	FLAG_DO    = (1 << RES_DO   ),
  	FLAG_DONE  = (1 << RES_DONE ),
  	FLAG_IN    = (1 << RES_IN   ),
- #endif
+ # endif
- #if ENABLE_HUSH_CASE
+ # if ENABLE_HUSH_CASE
  	FLAG_MATCH = (1 << RES_MATCH),
  	FLAG_ESAC  = (1 << RES_ESAC ),
- #endif
+ # endif
  	FLAG_START = (1 << RES_XXXX ),
  };
-Line 3056 
 static const struct reserved_combo* matc
+Line 4950 
 static const struct reserved_combo* matc
  	 * FLAG_START means the word must start a new compound list.
  	 */
  	static const struct reserved_combo reserved_list[] = {
- #if ENABLE_HUSH_IF
+ # if ENABLE_HUSH_IF
  		{ "!",     RES_NONE,  NOT_ASSIGNMENT , 0 },
  		{ "if",    RES_IF,    WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
  		{ "then",  RES_THEN,  WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
  		{ "elif",  RES_ELIF,  WORD_IS_KEYWORD, FLAG_THEN },
  		{ "else",  RES_ELSE,  WORD_IS_KEYWORD, FLAG_FI   },
  		{ "fi",    RES_FI,    NOT_ASSIGNMENT , FLAG_END  },
- #endif
+ # endif
- #if ENABLE_HUSH_LOOPS
+ # if ENABLE_HUSH_LOOPS
  		{ "for",   RES_FOR,   NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
  		{ "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
  		{ "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
  		{ "in",    RES_IN,    NOT_ASSIGNMENT , FLAG_DO   },
  		{ "do",    RES_DO,    WORD_IS_KEYWORD, FLAG_DONE },
  		{ "done",  RES_DONE,  NOT_ASSIGNMENT , FLAG_END  },
- #endif
+ # endif
- #if ENABLE_HUSH_CASE
+ # if ENABLE_HUSH_CASE
  		{ "case",  RES_CASE,  NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
  		{ "esac",  RES_ESAC,  NOT_ASSIGNMENT , FLAG_END  },
- #endif
+ # endif
  	};
  	const struct reserved_combo *r;
-Line 3085 
 static const struct reserved_combo* matc
+Line 4979 
 static const struct reserved_combo* matc
  	}
  	return NULL;
  }
+ /* Return 0: not a keyword, 1: keyword
+  */
  static int reserved_word(o_string *word, struct parse_context *ctx)
  {
- #if ENABLE_HUSH_CASE
+ # if ENABLE_HUSH_CASE
  	static const struct reserved_combo reserved_match = {
  		"",        RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
  	};
- #endif
+ # endif
  	const struct reserved_combo *r;
+ 	if (word->o_quoted)
+ 		return 0;
  	r = match_reserved_word(word);
  	if (!r)
  		return 0;
  	debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
- #if ENABLE_HUSH_CASE
+ # if ENABLE_HUSH_CASE
- 	if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
+ 	if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
- 		/* "case word IN ..." - IN part starts first match part */
+ 		/* "case word IN ..." - IN part starts first MATCH part */
  		r = &reserved_match;
- 	else
+ 	} else
- #endif
+ # endif
  	if (r->flag == 0) { /* '!' */
  		if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
- 			syntax(NULL);
+ 			syntax_error("! ! command");
- 			IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
+ 			ctx->ctx_res_w = RES_SNTX;
  		}
  		ctx->ctx_inverted = 1;
  		return 1;
  	}
  	if (r->flag & FLAG_START) {
- 		struct parse_context *new;
+ 		struct parse_context *old;
- 		debug_printf("push stack\n");
- 		new = xmalloc(sizeof(*new));
+ 		old = xmalloc(sizeof(*old));
- 		*new = *ctx;   /* physical copy */
+ 		debug_printf_parse("push stack %p\n", old);
+ 		*old = *ctx;   /* physical copy */
  		initialize_context(ctx);
- 		ctx->stack = new;
+ 		ctx->stack = old;
  	} else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
- 		syntax(NULL);
+ 		syntax_error_at(word->data);
  		ctx->ctx_res_w = RES_SNTX;
  		return 1;
+ 	} else {
+ 		/* "{...} fi" is ok. "{...} if" is not
+ 		 * Example:
+ 		 * if { echo foo; } then { echo bar; } fi */
+ 		if (ctx->command->group)
+ 			done_pipe(ctx, PIPE_SEQ);
  	}
  	ctx->ctx_res_w = r->res;
  	ctx->old_flag = r->flag;
+ 	word->o_assignment = r->assignment_flag;
  	if (ctx->old_flag & FLAG_END) {
  		struct parse_context *old;
- 		debug_printf("pop stack\n");
  		done_pipe(ctx, PIPE_SEQ);
+ 		debug_printf_parse("pop stack %p\n", ctx->stack);
  		old = ctx->stack;
  		old->command->group = ctx->list_head;
- 		old->command->grp_type = GRP_NORMAL;
+ 		old->command->cmd_type = CMD_NORMAL;
+ # if !BB_MMU
+ 		o_addstr(&old->as_string, ctx->as_string.data);
+ 		o_free_unsafe(&ctx->as_string);
+ 		old->command->group_as_string = xstrdup(old->as_string.data);
+ 		debug_printf_parse("pop, remembering as:'%s'\n",
+ 				old->command->group_as_string);
+ # endif
  		*ctx = *old;   /* physical copy */
  		free(old);
  	}
- 	word->o_assignment = r->assignment_flag;
  	return 1;
  }
- #endif
+ #endif /* HAS_KEYWORDS */
- //TODO: many, many callers don't check error from done_word()
  /* Word is complete, look at it and update parsing context.
-  * Normal return is 0. Syntax errors return 1. */
+  * Normal return is 0. Syntax errors return 1.
+  * Note: on return, word is reset, but not o_free'd!
+  */
  static int done_word(o_string *word, struct parse_context *ctx)
  {
  	struct command *command = ctx->command;
  	debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
- 	if (word->length == 0 && word->nonnull == 0) {
+ 	if (word->length == 0 && word->o_quoted == 0) {
  		debug_printf_parse("done_word return 0: true null, ignored\n");
  		return 0;
  	}
- 	/* If this word wasn't an assignment, next ones definitely
- 	 * can't be assignments. Even if they look like ones. */
- 	if (word->o_assignment != DEFINITELY_ASSIGNMENT
- 	 && word->o_assignment != WORD_IS_KEYWORD
- 	) {
- 		word->o_assignment = NOT_ASSIGNMENT;
- 	} else {
- 		if (word->o_assignment == DEFINITELY_ASSIGNMENT)
- 			command->assignment_cnt++;
- 		word->o_assignment = MAYBE_ASSIGNMENT;
- 	}
  	if (ctx->pending_redirect) {
  		/* We do not glob in e.g. >*.tmp case. bash seems to glob here
  		 * only if run as "bash", not "sh" */
+ 		/* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
+ 		 * "2.7 Redirection
+ 		 * ...the word that follows the redirection operator
+ 		 * shall be subjected to tilde expansion, parameter expansion,
+ 		 * command substitution, arithmetic expansion, and quote
+ 		 * removal. Pathname expansion shall not be performed
+ 		 * on the word by a non-interactive shell; an interactive
+ 		 * shell may perform it, but shall do so only when
+ 		 * the expansion would result in one word."
+ 		 */
  		ctx->pending_redirect->rd_filename = xstrdup(word->data);
- 		word->o_assignment = NOT_ASSIGNMENT;
+ 		/* Cater for >\file case:
- 		debug_printf("word stored in rd_filename: '%s'\n", word->data);
+ 		 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
+ 		 * Same with heredocs:
+ 		 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
+ 		 */
+ 		if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
+ 			unbackslash(ctx->pending_redirect->rd_filename);
+ 			/* Is it <<"HEREDOC"? */
+ 			if (word->o_quoted) {
+ 				ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
+ 			}
+ 		}
+ 		debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
+ 		ctx->pending_redirect = NULL;
  	} else {
- 		/* "{ echo foo; } echo bar" - bad */
+ 		/* If this word wasn't an assignment, next ones definitely
- 		/* NB: bash allows e.g. "if true; then { echo foo; } fi". TODO? */
+ 		 * can't be assignments. Even if they look like ones. */
- 		if (command->group) {
+ 		if (word->o_assignment != DEFINITELY_ASSIGNMENT
- 			syntax(NULL);
+ 		 && word->o_assignment != WORD_IS_KEYWORD
- 			debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
+ 		) {
- 			return 1;
+ 			word->o_assignment = NOT_ASSIGNMENT;
+ 		} else {
+ 			if (word->o_assignment == DEFINITELY_ASSIGNMENT)
+ 				command->assignment_cnt++;
+ 			word->o_assignment = MAYBE_ASSIGNMENT;
  		}
  #if HAS_KEYWORDS
- #if ENABLE_HUSH_CASE
+ # if ENABLE_HUSH_CASE
  		if (ctx->ctx_dsemicolon
  		 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
  		) {
-Line 3190 
 static int done_word(o_string *word, str
+Line 5121 
 static int done_word(o_string *word, str
  			/* ctx->ctx_res_w = RES_MATCH; */
  			ctx->ctx_dsemicolon = 0;
  		} else
- #endif
+ # endif
  		if (!command->argv /* if it's the first word... */
- #if ENABLE_HUSH_LOOPS
+ # if ENABLE_HUSH_LOOPS
  		 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
  		 && ctx->ctx_res_w != RES_IN
- #endif
+ # endif
+ # if ENABLE_HUSH_CASE
+ 		 && ctx->ctx_res_w != RES_CASE
+ # endif
  		) {
- 			debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
+ 			debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
  			if (reserved_word(word, ctx)) {
- 				o_reset(word);
+ 				o_reset_to_empty_unquoted(word);
- 				debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
+ 				debug_printf_parse("done_word return %d\n",
+ 						(ctx->ctx_res_w == RES_SNTX));
  				return (ctx->ctx_res_w == RES_SNTX);
  			}
+ # ifdef CMD_SINGLEWORD_NOGLOB_COND
+ 			if (strcmp(word->data, "export") == 0
+ #  if ENABLE_HUSH_LOCAL
+ 			 || strcmp(word->data, "local") == 0
+ #  endif
+ 			) {
+ 				command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
+ 			} else
+ # endif
+ # if ENABLE_HUSH_BASH_COMPAT
+ 			if (strcmp(word->data, "[[") == 0) {
+ 				command->cmd_type = CMD_SINGLEWORD_NOGLOB;
+ 			}
+ 			/* fall through */
+ # endif
  		}
  #endif
- 		if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
+ 		if (command->group) {
+ 			/* "{ echo foo; } echo bar" - bad */
+ 			syntax_error_at(word->data);
+ 			debug_printf_parse("done_word return 1: syntax error, "
+ 					"groups and arglists don't mix\n");
+ 			return 1;
+ 		}
+ 		if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
  		 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
  		 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
  		 /* (otherwise it's known to be not empty and is already safe) */
-Line 3232 
 static int done_word(o_string *word, str
+Line 5188 
 static int done_word(o_string *word, str
  		debug_print_strings("word appended to argv", command->argv);
  	}
- 	o_reset(word);
- 	ctx->pending_redirect = NULL;
  #if ENABLE_HUSH_LOOPS
- 	/* Force FOR to have just one word (variable name) */
- 	/* NB: basically, this makes hush see "for v in ..." syntax as if
- 	 * as it is "for v; in ...". FOR and IN become two pipe structs
- 	 * in parse tree. */
  	if (ctx->ctx_res_w == RES_FOR) {
- //TODO: check that command->argv[0] is a valid variable name!
+ 		if (word->o_quoted
+ 		 || !is_well_formed_var_name(command->argv[0], '\0')
+ 		) {
+ 			/* bash says just "not a valid identifier" */
+ 			syntax_error("not a valid identifier in for");
+ 			return 1;
+ 		}
+ 		/* Force FOR to have just one word (variable name) */
+ 		/* NB: basically, this makes hush see "for v in ..."
+ 		 * syntax as if it is "for v; in ...". FOR and IN become
+ 		 * two pipe structs in parse tree. */
  		done_pipe(ctx, PIPE_SEQ);
  	}
  #endif
-Line 3251 
 static int done_word(o_string *word, str
+Line 5210 
 static int done_word(o_string *word, str
  		done_pipe(ctx, PIPE_SEQ);
  	}
  #endif
- 	debug_printf_parse("done_word return 0\n");
- 	return 0;
- }
- /* Command (member of a pipe) is complete. The only possible error here
-  * is out of memory, in which case xmalloc exits. */
- static int done_command(struct parse_context *ctx)
- {
- 	/* The command is really already in the pipe structure, so
- 	 * advance the pipe counter and make a new, null command. */
- 	struct pipe *pi = ctx->pipe;
- 	struct command *command = ctx->command;
- 	if (command) {
- 		if (command->group == NULL
- 		 && command->argv == NULL
- 		 && command->redirects == NULL
- 		) {
- 			debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
- 			return pi->num_cmds;
- 		}
- 		pi->num_cmds++;
- 		debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
- 	} else {
- 		debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
- 	}
- 	/* Only real trickiness here is that the uncommitted
- 	 * command structure is not counted in pi->num_cmds. */
- 	pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
- 	command = &pi->cmds[pi->num_cmds];
- 	memset(command, 0, sizeof(*command));
- 	ctx->command = command;
+ 	o_reset_to_empty_unquoted(word);
- 	/* but ctx->pipe and ctx->list_head remain unchanged */
- 	return pi->num_cmds; /* used only for 0/nonzero check */
+ 	debug_printf_parse("done_word return 0\n");
+ 	return 0;
  }
- static void done_pipe(struct parse_context *ctx, pipe_style type)
- {
- 	int not_null;
- 	debug_printf_parse("done_pipe entered, followup %d\n", type);
- 	/* Close previous command */
- 	not_null = done_command(ctx);
- 	ctx->pipe->followup = type;
- 	IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
- 	IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
- 	IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
- 	/* Without this check, even just <enter> on command line generates
- 	 * tree of three NOPs (!). Which is harmless but annoying.
- 	 * IOW: it is safe to do it unconditionally.
- 	 * RES_NONE case is for "for a in; do ..." (empty IN set)
- 	 * to work, possibly other cases too. */
- 	if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
- 		struct pipe *new_p;
- 		debug_printf_parse("done_pipe: adding new pipe: "
- 				"not_null:%d ctx->ctx_res_w:%d\n",
- 				not_null, ctx->ctx_res_w);
- 		new_p = new_pipe();
- 		ctx->pipe->next = new_p;
- 		ctx->pipe = new_p;
- 		ctx->command = NULL; /* needed! */
- 		/* RES_THEN, RES_DO etc are "sticky" -
- 		 * they remain set for commands inside if/while.
- 		 * This is used to control execution.
- 		 * RES_FOR and RES_IN are NOT sticky (needed to support
- 		 * cases where variable or value happens to match a keyword):
- 		 */
- #if ENABLE_HUSH_LOOPS
- 		if (ctx->ctx_res_w == RES_FOR
- 		 || ctx->ctx_res_w == RES_IN)
- 			ctx->ctx_res_w = RES_NONE;
- #endif
- #if ENABLE_HUSH_CASE
- 		if (ctx->ctx_res_w == RES_MATCH)
- 			ctx->ctx_res_w = RES_CASEI;
- #endif
- 		/* Create the memory for command, roughly:
- 		 * ctx->pipe->cmds = new struct command;
- 		 * ctx->command = &ctx->pipe->cmds[0];
- 		 */
- 		done_command(ctx);
- 	}
- 	debug_printf_parse("done_pipe return\n");
- }
- /* Peek ahead in the in_str to find out if we have a "&n" construct,
+ /* Peek ahead in the input to find out if we have a "&n" construct,
   * as in "2>&1", that represents duplicating a file descriptor.
-  * Return either -2 (syntax error), -1 (no &), or the number found.
+  * Return:
+  * REDIRFD_CLOSE if >&- "close fd" construct is seen,
+  * REDIRFD_SYNTAX_ERR if syntax error,
+  * REDIRFD_TO_FILE if no & was seen,
+  * or the number found.
   */
- static int redirect_dup_num(struct in_str *input)
+ #if BB_MMU
+ #define parse_redir_right_fd(as_string, input) \
+ 	parse_redir_right_fd(input)
+ #endif
+ static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
  {
- 	int ch, d = 0, ok = 0;
+ 	int ch, d, ok;
  	ch = i_peek(input);
- 	if (ch != '&') return -1;
+ 	if (ch != '&')
+ 		return REDIRFD_TO_FILE;
- 	i_getch(input);  /* get the & */
+ 	ch = i_getch(input);  /* get the & */
+ 	nommu_addchr(as_string, ch);
  	ch = i_peek(input);
  	if (ch == '-') {
- 		i_getch(input);
+ 		ch = i_getch(input);
- 		return -3;  /* "-" represents "close me" */
+ 		nommu_addchr(as_string, ch);
+ 		return REDIRFD_CLOSE;
  	}
- 	while (isdigit(ch)) {
+ 	d = 0;
+ 	ok = 0;
+ 	while (ch != EOF && isdigit(ch)) {
  		d = d*10 + (ch-'0');
  		ok = 1;
- 		i_getch(input);
+ 		ch = i_getch(input);
+ 		nommu_addchr(as_string, ch);
  		ch = i_peek(input);
  	}
  	if (ok) return d;
+ //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
  	bb_error_msg("ambiguous redirect");
- 	return -2;
+ 	return REDIRFD_SYNTAX_ERR;
+ }
+ /* Return code is 0 normal, 1 if a syntax error is detected
+  */
+ static int parse_redirect(struct parse_context *ctx,
+ 		int fd,
+ 		redir_type style,
+ 		struct in_str *input)
+ {
+ 	struct command *command = ctx->command;
+ 	struct redir_struct *redir;
+ 	struct redir_struct **redirp;
+ 	int dup_num;
+ 	dup_num = REDIRFD_TO_FILE;
+ 	if (style != REDIRECT_HEREDOC) {
+ 		/* Check for a '>&1' type redirect */
+ 		dup_num = parse_redir_right_fd(&ctx->as_string, input);
+ 		if (dup_num == REDIRFD_SYNTAX_ERR)
+ 			return 1;
+ 	} else {
+ 		int ch = i_peek(input);
+ 		dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
+ 		if (dup_num) { /* <<-... */
+ 			ch = i_getch(input);
+ 			nommu_addchr(&ctx->as_string, ch);
+ 			ch = i_peek(input);
+ 		}
+ 	}
+ 	if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
+ 		int ch = i_peek(input);
+ 		if (ch == '|') {
+ 			/* >|FILE redirect ("clobbering" >).
+ 			 * Since we do not support "set -o noclobber" yet,
+ 			 * >| and > are the same for now. Just eat |.
+ 			 */
+ 			ch = i_getch(input);
+ 			nommu_addchr(&ctx->as_string, ch);
+ 		}
+ 	}
+ 	/* Create a new redir_struct and append it to the linked list */
+ 	redirp = &command->redirects;
+ 	while ((redir = *redirp) != NULL) {
+ 		redirp = &(redir->next);
+ 	}
+ 	*redirp = redir = xzalloc(sizeof(*redir));
+ 	/* redir->next = NULL; */
+ 	/* redir->rd_filename = NULL; */
+ 	redir->rd_type = style;
+ 	redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
+ 	debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
+ 				redir_table[style].descrip);
+ 	redir->rd_dup = dup_num;
+ 	if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
+ 		/* Erik had a check here that the file descriptor in question
+ 		 * is legit; I postpone that to "run time"
+ 		 * A "-" representation of "close me" shows up as a -3 here */
+ 		debug_printf_parse("duplicating redirect '%d>&%d'\n",
+ 				redir->rd_fd, redir->rd_dup);
+ 	} else {
+ 		/* Set ctx->pending_redirect, so we know what to do at the
+ 		 * end of the next parsed word. */
+ 		ctx->pending_redirect = redir;
+ 	}
+ 	return 0;
  }
  /* If a redirect is immediately preceded by a number, that number is
-Line 3376 
 static int redirect_dup_num(struct in_st
+Line 5340 
 static int redirect_dup_num(struct in_st
   *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
   *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
   *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
-  * A -1 output from this program means no valid number was found, so the
+  *
-  * caller should use the appropriate default for this redirection.
+  * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
+  * "2.7 Redirection
+  * ... If n is quoted, the number shall not be recognized as part of
+  * the redirection expression. For example:
+  * echo \2>a
+  * writes the character 2 into file a"
+  * We are getting it right by setting ->o_quoted on any \<char>
+  *
+  * A -1 return means no valid number was found,
+  * the caller should use the appropriate default for this redirection.
   */
  static int redirect_opt_num(o_string *o)
  {
  	int num;
- 	if (o->length == 0)
+ 	if (o->data == NULL)
  		return -1;
- 	for (num = 0; num < o->length; num++) {
+ 	num = bb_strtou(o->data, NULL, 10);
- 		if (!isdigit(o->data[num])) {
+ 	if (errno || num < 0)
- 			return -1;
+ 		return -1;
+ 	o_reset_to_empty_unquoted(o);
+ 	return num;
+ }
+ #if BB_MMU
+ #define fetch_till_str(as_string, input, word, skip_tabs) \
+ 	fetch_till_str(input, word, skip_tabs)
+ #endif
+ static char *fetch_till_str(o_string *as_string,
+ 		struct in_str *input,
+ 		const char *word,
+ 		int skip_tabs)
+ {
+ 	o_string heredoc = NULL_O_STRING;
+ 	int past_EOL = 0;
+ 	int ch;
+ 	goto jump_in;
+ 	while (1) {
+ 		ch = i_getch(input);
+ 		nommu_addchr(as_string, ch);
+ 		if (ch == '\n') {
+ 			if (strcmp(heredoc.data + past_EOL, word) == 0) {
+ 				heredoc.data[past_EOL] = '\0';
+ 				debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
+ 				return heredoc.data;
+ 			}
+ 			do {
+ 				o_addchr(&heredoc, ch);
+ 				past_EOL = heredoc.length;
+  jump_in:
+ 				do {
+ 					ch = i_getch(input);
+ 					nommu_addchr(as_string, ch);
+ 				} while (skip_tabs && ch == '\t');
+ 			} while (ch == '\n');
+ 		}
+ 		if (ch == EOF) {
+ 			o_free_unsafe(&heredoc);
+ 			return NULL;
  		}
+ 		o_addchr(&heredoc, ch);
+ 		nommu_addchr(as_string, ch);
  	}
- 	num = atoi(o->data);
- 	o_reset(o);
- 	return num;
  }
+ /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
+  * and load them all. There should be exactly heredoc_cnt of them.
+  */
+ static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
+ {
+ 	struct pipe *pi = ctx->list_head;
+ 	while (pi && heredoc_cnt) {
+ 		int i;
+ 		struct command *cmd = pi->cmds;
+ 		debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
+ 				pi->num_cmds,
+ 				cmd->argv ? cmd->argv[0] : "NONE");
+ 		for (i = 0; i < pi->num_cmds; i++) {
+ 			struct redir_struct *redir = cmd->redirects;
+ 			debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
+ 					i, cmd->argv ? cmd->argv[0] : "NONE");
+ 			while (redir) {
+ 				if (redir->rd_type == REDIRECT_HEREDOC) {
+ 					char *p;
+ 					redir->rd_type = REDIRECT_HEREDOC2;
+ 					/* redir->rd_dup is (ab)used to indicate <<- */
+ 					p = fetch_till_str(&ctx->as_string, input,
+ 						redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
+ 					if (!p) {
+ 						syntax_error("unexpected EOF in here document");
+ 						return 1;
+ 					}
+ 					free(redir->rd_filename);
+ 					redir->rd_filename = p;
+ 					heredoc_cnt--;
+ 				}
+ 				redir = redir->next;
+ 			}
+ 			cmd++;
+ 		}
+ 		pi = pi->next;
+ 	}
+ #if 0
+ 	/* Should be 0. If it isn't, it's a parse error */
+ 	if (heredoc_cnt)
+ 		bb_error_msg_and_die("heredoc BUG 2");
+ #endif
+ 	return 0;
+ }
  #if ENABLE_HUSH_TICK
- static FILE *generate_stream_from_list(struct pipe *head)
+ static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
  {
- 	FILE *pf;
+ 	pid_t pid;
- 	int pid, channel[2];
+ 	int channel[2];
+ # if !BB_MMU
+ 	char **to_free = NULL;
+ # endif
  	xpipe(channel);
- /* *** NOMMU WARNING *** */
- /* By using vfork here, we suspend parent till child exits or execs.
-  * If child will not do it before it fills the pipe, it can block forever
-  * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
-  * Try this script:
-  * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
-  * huge=`cat TESTFILE` # will block here forever
-  * echo OK
-  */
  	pid = BB_MMU ? fork() : vfork();
  	if (pid < 0)
  		bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
  	if (pid == 0) { /* child */
- 		if (ENABLE_HUSH_JOB)
+ 		disable_restore_tty_pgrp_on_exit();
- 			die_sleep = 0; /* let nofork's xfuncs die */
+ 		/* Process substitution is not considered to be usual
+ 		 * 'command execution'.
+ 		 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
+ 		 */
+ 		bb_signals(0
+ 			+ (1 << SIGTSTP)
+ 			+ (1 << SIGTTIN)
+ 			+ (1 << SIGTTOU)
+ 			, SIG_IGN);
+ 		CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
  		close(channel[0]); /* NB: close _first_, then move fd! */
  		xmove_fd(channel[1], 1);
  		/* Prevent it from trying to handle ctrl-z etc */
- #if ENABLE_HUSH_JOB
+ 		IF_HUSH_JOB(G.run_list_level = 1;)
- 		G.run_list_level = 1;
+ 		/* Awful hack for `trap` or $(trap).
- #endif
+ 		 *
- 		/* Process substitution is not considered to be usual
+ 		 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
- 		 * 'command execution'.
+ 		 * contains an example where "trap" is executed in a subshell:
- 		 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
+ 		 *
- 		/* Not needed, we are relying on it being disabled
+ 		 * save_traps=$(trap)
- 		 * everywhere outside actual command execution. */
+ 		 * ...
- 		/*set_jobctrl_sighandler(SIG_IGN);*/
+ 		 * eval "$save_traps"
- 		set_misc_sighandler(SIG_DFL);
+ 		 *
- 		/* Freeing 'head' here would break NOMMU. */
+ 		 * Standard does not say that "trap" in subshell shall print
- 		_exit(run_list(head));
+ 		 * parent shell's traps. It only says that its output
+ 		 * must have suitable form, but then, in the above example
+ 		 * (which is not supposed to be normative), it implies that.
+ 		 *
+ 		 * bash (and probably other shell) does implement it
+ 		 * (traps are reset to defaults, but "trap" still shows them),
+ 		 * but as a result, "trap" logic is hopelessly messed up:
+ 		 *
+ 		 * # trap
+ 		 * trap -- 'echo Ho' SIGWINCH  <--- we have a handler
+ 		 * # (trap)        <--- trap is in subshell - no output (correct, traps are reset)
+ 		 * # true | trap   <--- trap is in subshell - no output (ditto)
+ 		 * # echo `true | trap`    <--- in subshell - output (but traps are reset!)
+ 		 * trap -- 'echo Ho' SIGWINCH
+ 		 * # echo `(trap)`         <--- in subshell in subshell - output
+ 		 * trap -- 'echo Ho' SIGWINCH
+ 		 * # echo `true | (trap)`  <--- in subshell in subshell in subshell - output!
+ 		 * trap -- 'echo Ho' SIGWINCH
+ 		 *
+ 		 * The rules when to forget and when to not forget traps
+ 		 * get really complex and nonsensical.
+ 		 *
+ 		 * Our solution: ONLY bare $(trap) or `trap` is special.
+ 		 */
+ 		s = skip_whitespace(s);
+ 		if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
+ 		{
+ 			static const char *const argv[] = { NULL, NULL };
+ 			builtin_trap((char**)argv);
+ 			exit(0); /* not _exit() - we need to fflush */
+ 		}
+ # if BB_MMU
+ 		reset_traps_to_defaults();
+ 		parse_and_run_string(s);
+ 		_exit(G.last_exitcode);
+ # else
+ 	/* We re-execute after vfork on NOMMU. This makes this script safe:
+ 	 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
+ 	 * huge=`cat BIG` # was blocking here forever
+ 	 * echo OK
+ 	 */
+ 		re_execute_shell(&to_free,
+ 				s,
+ 				G.global_argv[0],
+ 				G.global_argv + 1,
+ 				NULL);
+ # endif
  	}
+ 	/* parent */
+ 	*pid_p = pid;
+ # if ENABLE_HUSH_FAST
+ 	G.count_SIGCHLD++;
+ //bb_error_msg("[%d] fork in generate_stream_from_string: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
+ # endif
+ 	enable_restore_tty_pgrp_on_exit();
+ # if !BB_MMU
+ 	free(to_free);
+ # endif
  	close(channel[1]);
- 	pf = fdopen(channel[0], "r");
+ 	close_on_exec_on(channel[0]);
- 	return pf;
+ 	return xfdopen_for_read(channel[0]);
- 	/* 'head' is freed by the caller */
  }
  /* Return code is exit status of the process that is run. */
- static int process_command_subs(o_string *dest,
+ static int process_command_subs(o_string *dest, const char *s)
- 		struct in_str *input,
- 		const char *subst_end)
  {
- 	int retcode, ch, eol_cnt;
+ 	FILE *fp;
- 	o_string result = NULL_O_STRING;
- 	struct parse_context inner;
- 	FILE *p;
  	struct in_str pipe_str;
+ 	pid_t pid;
+ 	int status, ch, eol_cnt;
- 	initialize_context(&inner);
+ 	fp = generate_stream_from_string(s, &pid);
- 	/* Recursion to generate command */
- 	retcode = parse_stream(&result, &inner, input, subst_end);
- 	if (retcode != 0)
- 		return retcode;  /* syntax error or EOF */
- 	done_word(&result, &inner);
- 	done_pipe(&inner, PIPE_SEQ);
- 	o_free(&result);
- 	p = generate_stream_from_list(inner.list_head);
- 	if (p == NULL)
- 		return 1;
- 	close_on_exec_on(fileno(p));
- 	setup_file_in_str(&pipe_str, p);
  	/* Now send results of command back into original context */
+ 	setup_file_in_str(&pipe_str, fp);
  	eol_cnt = 0;
  	while ((ch = i_getch(&pipe_str)) != EOF) {
  		if (ch == '\n') {
-Line 3480 
 static int process_command_subs(o_string
+Line 5586 
 static int process_command_subs(o_string
  		o_addQchr(dest, ch);
  	}
- 	debug_printf("done reading from pipe, pclose()ing\n");
+ 	debug_printf("done reading from `cmd` pipe, closing it\n");
- 	/* This is the step that wait()s for the child.  Should be pretty
+ 	fclose(fp);
- 	 * safe, since we just read an EOF from its stdout.  We could try
+ 	/* We need to extract exitcode. Test case
- 	 * to do better, by using wait(), and keeping track of background jobs
+ 	 * "true; echo `sleep 1; false` $?"
- 	 * at the same time.  That would be a lot of work, and contrary
+ 	 * should print 1 */
- 	 * to the KISS philosophy of this program. */
+ 	safe_waitpid(pid, &status, 0);
- 	retcode = fclose(p);
+ 	debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
- 	free_pipe_list(inner.list_head, /* indent: */ 0);
+ 	return WEXITSTATUS(status);
- 	debug_printf("closed FILE from child, retcode=%d\n", retcode);
- 	return retcode;
  }
- #endif
+ #endif /* ENABLE_HUSH_TICK */
+ #if !ENABLE_HUSH_FUNCTIONS
+ #define parse_group(dest, ctx, input, ch) \
+ 	parse_group(ctx, input, ch)
+ #endif
  static int parse_group(o_string *dest, struct parse_context *ctx,
  	struct in_str *input, int ch)
  {
  	/* dest contains characters seen prior to ( or {.
- 	 * Typically it's empty, but for functions defs,
+ 	 * Typically it's empty, but for function defs,
  	 * it contains function name (without '()'). */
- 	int rcode;
+ 	struct pipe *pipe_list;
- 	const char *endch = NULL;
+ 	int endch;
- 	struct parse_context sub;
  	struct command *command = ctx->command;
  	debug_printf_parse("parse_group entered\n");
  #if ENABLE_HUSH_FUNCTIONS
- 	if (ch == 'F') { /* function definition? */
+ 	if (ch == '(' && !dest->o_quoted) {
- 		bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
+ 		if (dest->length)
- 		//command->fname = dest->data;
+ 			if (done_word(dest, ctx))
- 		command->grp_type = GRP_FUNCTION;
+ 				return 1;
- //TODO: review every o_reset() location... do they handle all o_string fields correctly?
+ 		if (!command->argv)
- 		memset(dest, 0, sizeof(*dest));
+ 			goto skip; /* (... */
+ 		if (command->argv[1]) { /* word word ... (... */
+ 			syntax_error_unexpected_ch('(');
+ 			return 1;
+ 		}
+ 		/* it is "word(..." or "word (..." */
+ 		do
+ 			ch = i_getch(input);
+ 		while (ch == ' ' || ch == '\t');
+ 		if (ch != ')') {
+ 			syntax_error_unexpected_ch(ch);
+ 			return 1;
+ 		}
+ 		nommu_addchr(&ctx->as_string, ch);
+ 		do
+ 			ch = i_getch(input);
+ 		while (ch == ' ' || ch == '\t' || ch == '\n');
+ 		if (ch != '{') {
+ 			syntax_error_unexpected_ch(ch);
+ 			return 1;
+ 		}
+ 		nommu_addchr(&ctx->as_string, ch);
+ 		command->cmd_type = CMD_FUNCDEF;
+ 		goto skip;
  	}
  #endif
- 	if (command->argv /* word [word](... */
- 	 || dest->length /* word(... */
+ #if 0 /* Prevented by caller */
- 	 || dest->nonnull /* ""(... */
+ 	if (command->argv /* word [word]{... */
+ 	 || dest->length /* word{... */
+ 	 || dest->o_quoted /* ""{... */
  	) {
- 		syntax(NULL);
+ 		syntax_error(NULL);
- 		debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
+ 		debug_printf_parse("parse_group return 1: "
+ 			"syntax error, groups and arglists don't mix\n");
  		return 1;
  	}
- 	initialize_context(&sub);
+ #endif
- 	endch = "}";
+ #if ENABLE_HUSH_FUNCTIONS
+  skip:
+ #endif
+ 	endch = '}';
  	if (ch == '(') {
- 		endch = ")";
+ 		endch = ')';
- 		command->grp_type = GRP_SUBSHELL;
+ 		command->cmd_type = CMD_SUBSHELL;
+ 	} else {
+ 		/* bash does not allow "{echo...", requires whitespace */
+ 		ch = i_getch(input);
+ 		if (ch != ' ' && ch != '\t' && ch != '\n') {
+ 			syntax_error_unexpected_ch(ch);
+ 			return 1;
+ 		}
+ 		nommu_addchr(&ctx->as_string, ch);
  	}
- 	rcode = parse_stream(dest, &sub, input, endch);
- 	if (rcode == 0) {
+ 	{
- 		done_word(dest, &sub); /* finish off the final word in the subcontext */
+ #if !BB_MMU
- 		done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
+ 		char *as_string = NULL;
- 		command->group = sub.list_head;
+ #endif
+ 		pipe_list = parse_stream(&as_string, input, endch);
+ #if !BB_MMU
+ 		if (as_string)
+ 			o_addstr(&ctx->as_string, as_string);
+ #endif
+ 		/* empty ()/{} or parse error? */
+ 		if (!pipe_list || pipe_list == ERR_PTR) {
+ 			/* parse_stream already emitted error msg */
+ #if !BB_MMU
+ 			free(as_string);
+ #endif
+ 			debug_printf_parse("parse_group return 1: "
+ 				"parse_stream returned %p\n", pipe_list);
+ 			return 1;
+ 		}
+ 		command->group = pipe_list;
+ #if !BB_MMU
+ 		as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
+ 		command->group_as_string = as_string;
+ 		debug_printf_parse("end of group, remembering as:'%s'\n",
+ 				command->group_as_string);
+ #endif
  	}
- 	debug_printf_parse("parse_group return %d\n", rcode);
+ 	debug_printf_parse("parse_group return 0\n");
- 	return rcode;
+ 	return 0;
  	/* command remains "open", available for possible redirects */
  }
- /* Basically useful version until someone wants to get fancier,
+ #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
-  * see the bash man page under "Parameter Expansion" */
- static const char *lookup_param(const char *src)
- {
- 	struct variable *var = get_local_var(src);
- 	if (var)
- 		return strchr(var->varstr, '=') + 1;
- 	return NULL;
- }
- #if ENABLE_HUSH_TICK
  /* Subroutines for copying $(...) and `...` things */
  static void add_till_backquote(o_string *dest, struct in_str *input);
  /* '...' */
-Line 3557 
 static void add_till_single_quote(o_stri
+Line 5714 
 static void add_till_single_quote(o_stri
  {
  	while (1) {
  		int ch = i_getch(input);
- 		if (ch == EOF)
+ 		if (ch == EOF) {
- 			break;
+ 			syntax_error_unterm_ch('\'');
+ 			/*xfunc_die(); - redundant */
+ 		}
  		if (ch == '\'')
- 			break;
+ 			return;
  		o_addchr(dest, ch);
  	}
  }
-Line 3569 
 static void add_till_double_quote(o_stri
+Line 5728 
 static void add_till_double_quote(o_stri
  {
  	while (1) {
  		int ch = i_getch(input);
+ 		if (ch == EOF) {
+ 			syntax_error_unterm_ch('"');
+ 			/*xfunc_die(); - redundant */
+ 		}
  		if (ch == '"')
- 			break;
+ 			return;
  		if (ch == '\\') {  /* \x. Copy both chars. */
  			o_addchr(dest, ch);
  			ch = i_getch(input);
  		}
- 		if (ch == EOF)
- 			break;
  		o_addchr(dest, ch);
  		if (ch == '`') {
  			add_till_backquote(dest, input);
-Line 3604 
 static void add_till_backquote(o_string
+Line 5765 
 static void add_till_backquote(o_string
  {
  	while (1) {
  		int ch = i_getch(input);
+ 		if (ch == EOF) {
+ 			syntax_error_unterm_ch('`');
+ 			/*xfunc_die(); - redundant */
+ 		}
  		if (ch == '`')
- 			break;
+ 			return;
- 		if (ch == '\\') {  /* \x. Copy both chars unless it is \` */
+ 		if (ch == '\\') {
+ 			/* \x. Copy both chars unless it is \` */
  			int ch2 = i_getch(input);
+ 			if (ch2 == EOF) {
+ 				syntax_error_unterm_ch('`');
+ 				/*xfunc_die(); - redundant */
+ 			}
  			if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
  				o_addchr(dest, ch);
  			ch = ch2;
  		}
- 		if (ch == EOF)
- 			break;
  		o_addchr(dest, ch);
  	}
  }
-Line 3629 
 static void add_till_backquote(o_string
+Line 5797 
 static void add_till_backquote(o_string
   * echo $(echo 'TEST)' BEST)            TEST) BEST
   * echo $(echo \(\(TEST\) BEST)         ((TEST) BEST
   */
- static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
+ static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
  {
  	int count = 0;
  	while (1) {
  		int ch = i_getch(input);
- 		if (ch == EOF)
+ 		if (ch == EOF) {
- 			break;
+ 			syntax_error_unterm_ch(')');
+ 			/*xfunc_die(); - redundant */
+ 		}
  		if (ch == '(')
  			count++;
- 		if (ch == ')')
+ 		if (ch == ')') {
- 			if (--count < 0)
+ 			if (--count < 0) {
- 				break;
+ 				if (!dbl)
+ 					break;
+ 				if (i_peek(input) == ')') {
+ 					i_getch(input);
+ 					break;
+ 				}
+ 			}
+ 		}
  		o_addchr(dest, ch);
  		if (ch == '\'') {
  			add_till_single_quote(dest, input);
-Line 3652 
 static void add_till_closing_curly_brace
+Line 5829 
 static void add_till_closing_curly_brace
  			o_addchr(dest, ch);
  			continue;
  		}
- 		if (ch == '\\') { /* \x. Copy verbatim. Important for  \(, \) */
+ 		if (ch == '\\') {
+ 			/* \x. Copy verbatim. Important for  \(, \) */
  			ch = i_getch(input);
- 			if (ch == EOF)
+ 			if (ch == EOF) {
- 				break;
+ 				syntax_error_unterm_ch(')');
+ 				/*xfunc_die(); - redundant */
+ 			}
  			o_addchr(dest, ch);
  			continue;
  		}
  	}
  }
- #endif /* ENABLE_HUSH_TICK */
+ #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
  /* Return code: 0 for OK, 1 for syntax error */
- static int handle_dollar(o_string *dest, struct in_str *input)
+ #if BB_MMU
+ #define handle_dollar(as_string, dest, input) \
+ 	handle_dollar(dest, input)
+ #endif
+ static int handle_dollar(o_string *as_string,
+ 		o_string *dest,
+ 		struct in_str *input)
  {
  	int ch = i_peek(input);  /* first character after the $ */
- 	unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
+ 	unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
  	debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
  	if (isalpha(ch)) {
- 		i_getch(input);
+ 		ch = i_getch(input);
+ 		nommu_addchr(as_string, ch);
   make_var:
  		o_addchr(dest, SPECIAL_VAR_SYMBOL);
  		while (1) {
-Line 3681 
 static int handle_dollar(o_string *dest,
+Line 5868 
 static int handle_dollar(o_string *dest,
  			ch = i_peek(input);
  			if (!isalnum(ch) && ch != '_')
  				break;
- 			i_getch(input);
+ 			ch = i_getch(input);
+ 			nommu_addchr(as_string, ch);
  		}
  		o_addchr(dest, SPECIAL_VAR_SYMBOL);
  	} else if (isdigit(ch)) {
   make_one_char_var:
- 		i_getch(input);
+ 		ch = i_getch(input);
+ 		nommu_addchr(as_string, ch);
  		o_addchr(dest, SPECIAL_VAR_SYMBOL);
  		debug_printf_parse(": '%c'\n", ch);
  		o_addchr(dest, ch | quote_mask);
  		o_addchr(dest, SPECIAL_VAR_SYMBOL);
  	} else switch (ch) {
- 		case '$': /* pid */
+ 	case '$': /* pid */
- 		case '!': /* last bg pid */
+ 	case '!': /* last bg pid */
- 		case '?': /* last exit code */
+ 	case '?': /* last exit code */
- 		case '#': /* number of args */
+ 	case '#': /* number of args */
- 		case '*': /* args */
+ 	case '*': /* args */
- 		case '@': /* args */
+ 	case '@': /* args */
- 			goto make_one_char_var;
+ 		goto make_one_char_var;
- 		case '{':
+ 	case '{': {
- 			o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ 		bool first_char, all_digits;
- 			i_getch(input);
+ 		int expansion;
- 			/* XXX maybe someone will try to escape the '}' */
- 			while (1) {
+ 		ch = i_getch(input);
- 				ch = i_getch(input);
+ 		nommu_addchr(as_string, ch);
- 				if (ch == '}')
+ 		o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ 		/* TODO: maybe someone will try to escape the '}' */
+ 		expansion = 0;
+ 		first_char = true;
+ 		all_digits = false;
+ 		while (1) {
+ 			ch = i_getch(input);
+ 			nommu_addchr(as_string, ch);
+ 			if (ch == '}') {
+ 				break;
+ 			}
+ 			if (first_char) {
+ 				if (ch == '#') {
+ 					/* ${#var}: length of var contents */
+ 					goto char_ok;
+ 				}
+ 				if (isdigit(ch)) {
+ 					all_digits = true;
+ 					goto char_ok;
+ 				}
+ 				/* They're being verbose and doing ${?} */
+ 				if (i_peek(input) == '}' && strchr("$!?#*@_", ch))
+ 					goto char_ok;
+ 			}
+ 			if (expansion < 2
+ 			 && (  (all_digits && !isdigit(ch))
+ 			    || (!all_digits && !isalnum(ch) && ch != '_')
+ 			    )
+ 			) {
+ 				/* handle parameter expansions
+ 				 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
+ 				 */
+ 				if (first_char)
+ 					goto case_default;
+ 				switch (ch) {
+ 				case ':': /* null modifier */
+ 					if (expansion == 0) {
+ 						debug_printf_parse(": null modifier\n");
+ 						++expansion;
+ 						break;
+ 					}
+ 					goto case_default;
+ 				case '#': /* remove prefix */
+ 				case '%': /* remove suffix */
+ 					if (expansion == 0) {
+ 						debug_printf_parse(": remove suffix/prefix\n");
+ 						expansion = 2;
+ 						break;
+ 					}
+ 					goto case_default;
+ 				case '-': /* default value */
+ 				case '=': /* assign default */
+ 				case '+': /* alternative */
+ 				case '?': /* error indicate */
+ 					debug_printf_parse(": parameter expansion\n");
+ 					expansion = 2;
  					break;
- 				if (!isalnum(ch) && ch != '_') {
+ 				default:
- 					syntax("unterminated ${name}");
+ 				case_default:
+ 					syntax_error_unterm_str("${name}");
  					debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
  					return 1;
  				}
- 				debug_printf_parse(": '%c'\n", ch);
- 				o_addchr(dest, ch | quote_mask);
- 				quote_mask = 0;
  			}
+  char_ok:
+ 			debug_printf_parse(": '%c'\n", ch);
+ 			o_addchr(dest, ch | quote_mask);
+ 			quote_mask = 0;
+ 			first_char = false;
+ 		} /* while (1) */
+ 		o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ 		break;
+ 	}
+ #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
+ 	case '(': {
+ # if !BB_MMU
+ 		int pos;
+ # endif
+ 		ch = i_getch(input);
+ 		nommu_addchr(as_string, ch);
+ # if ENABLE_SH_MATH_SUPPORT
+ 		if (i_peek(input) == '(') {
+ 			ch = i_getch(input);
+ 			nommu_addchr(as_string, ch);
  			o_addchr(dest, SPECIAL_VAR_SYMBOL);
- 			break;
+ 			o_addchr(dest, /*quote_mask |*/ '+');
- #if ENABLE_HUSH_TICK
+ #  if !BB_MMU
- 		case '(': {
+ 			pos = dest->length;
- 			//int pos = dest->length;
+ #  endif
- 			i_getch(input);
+ 			add_till_closing_paren(dest, input, true);
- 			o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ #  if !BB_MMU
- 			o_addchr(dest, quote_mask | '`');
+ 			if (as_string) {
- 			add_till_closing_curly_brace(dest, input);
+ 				o_addstr(as_string, dest->data + pos);
- 			//debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
+ 				o_addchr(as_string, ')');
+ 				o_addchr(as_string, ')');
+ 			}
+ #  endif
  			o_addchr(dest, SPECIAL_VAR_SYMBOL);
  			break;
  		}
+ # endif
+ # if ENABLE_HUSH_TICK
+ 		o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ 		o_addchr(dest, quote_mask | '`');
+ #  if !BB_MMU
+ 		pos = dest->length;
+ #  endif
+ 		add_till_closing_paren(dest, input, false);
+ #  if !BB_MMU
+ 		if (as_string) {
+ 			o_addstr(as_string, dest->data + pos);
+ 			o_addchr(as_string, ')');
+ 		}
+ #  endif
+ 		o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ # endif
+ 		break;
+ 	}
  #endif
- 		case '_':
+ 	case '_':
- 			i_getch(input);
+ 		ch = i_getch(input);
- 			ch = i_peek(input);
+ 		nommu_addchr(as_string, ch);
- 			if (isalnum(ch)) { /* it's $_name or $_123 */
+ 		ch = i_peek(input);
- 				ch = '_';
+ 		if (isalnum(ch)) { /* it's $_name or $_123 */
- 				goto make_var;
+ 			ch = '_';
- 			}
+ 			goto make_var;
- 			/* else: it's $_ */
+ 		}
- 		case '-':
+ 		/* else: it's $_ */
- 			/* still unhandled, but should be eventually */
+ 	/* TODO: $_ and $-: */
- 			bb_error_msg("unhandled syntax: $%c", ch);
+ 	/* $_ Shell or shell script name; or last argument of last command
- 			return 1;
+ 	 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
- 			break;
+ 	 * but in command's env, set to full pathname used to invoke it */
- 		default:
+ 	/* $- Option flags set by set builtin or shell options (-i etc) */
- 			o_addQchr(dest, '$');
+ 	default:
+ 		o_addQchr(dest, '$');
  	}
  	debug_printf_parse("handle_dollar return 0\n");
  	return 0;
  }
- /* Scan input, call done_word() whenever full IFS delimited word was seen.
+ #if BB_MMU
-  * Call done_pipe if '\n' was seen (and end_trigger != NULL).
+ #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
-  * Return code is 0 if end_trigger char is met,
+ 	parse_stream_dquoted(dest, input, dquote_end)
-  * -1 on EOF (but if end_trigger == NULL then return 0),
+ #endif
-  * 1 for syntax error */
+ static int parse_stream_dquoted(o_string *as_string,
- static int parse_stream(o_string *dest, struct parse_context *ctx,
+ 		o_string *dest,
- 	struct in_str *input, const char *end_trigger)
+ 		struct in_str *input,
- {
+ 		int dquote_end)
- 	int ch, m;
+ {
- 	int redir_fd;
+ 	int ch;
- 	redir_type redir_style;
- 	int shadow_quote = dest->o_quote;
  	int next;
- 	/* Only double-quote state is handled in the state variable dest->o_quote.
+  again:
+ 	ch = i_getch(input);
+ 	if (ch != EOF)
+ 		nommu_addchr(as_string, ch);
+ 	if (ch == dquote_end) { /* may be only '"' or EOF */
+ 		if (dest->o_assignment == NOT_ASSIGNMENT)
+ 			dest->o_escape ^= 1;
+ 		debug_printf_parse("parse_stream_dquoted return 0\n");
+ 		return 0;
+ 	}
+ 	/* note: can't move it above ch == dquote_end check! */
+ 	if (ch == EOF) {
+ 		syntax_error_unterm_ch('"');
+ 		/*xfunc_die(); - redundant */
+ 	}
+ 	next = '\0';
+ 	if (ch != '\n') {
+ 		next = i_peek(input);
+ 	}
+ 	debug_printf_parse("\" ch=%c (%d) escape=%d\n",
+ 					ch, ch, dest->o_escape);
+ 	if (ch == '\\') {
+ 		if (next == EOF) {
+ 			syntax_error("\\<eof>");
+ 			xfunc_die();
+ 		}
+ 		/* bash:
+ 		 * "The backslash retains its special meaning [in "..."]
+ 		 * only when followed by one of the following characters:
+ 		 * $, `, ", \, or <newline>.  A double quote may be quoted
+ 		 * within double quotes by preceding it with a backslash."
+ 		 */
+ 		if (strchr("$`\"\\\n", next) != NULL) {
+ 			ch = i_getch(input);
+ 			if (ch != '\n') {
+ 				o_addqchr(dest, ch);
+ 				nommu_addchr(as_string, ch);
+ 			}
+ 		} else {
+ 			o_addqchr(dest, '\\');
+ 			nommu_addchr(as_string, '\\');
+ 		}
+ 		goto again;
+ 	}
+ 	if (ch == '$') {
+ 		if (handle_dollar(as_string, dest, input) != 0) {
+ 			debug_printf_parse("parse_stream_dquoted return 1: "
+ 					"handle_dollar returned non-0\n");
+ 			return 1;
+ 		}
+ 		goto again;
+ 	}
+ #if ENABLE_HUSH_TICK
+ 	if (ch == '`') {
+ 		//int pos = dest->length;
+ 		o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ 		o_addchr(dest, 0x80 | '`');
+ 		add_till_backquote(dest, input);
+ 		o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ 		//debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
+ 		goto again;
+ 	}
+ #endif
+ 	o_addQchr(dest, ch);
+ 	if (ch == '='
+ 	 && (dest->o_assignment == MAYBE_ASSIGNMENT
+ 	    || dest->o_assignment == WORD_IS_KEYWORD)
+ 	 && is_well_formed_var_name(dest->data, '=')
+ 	) {
+ 		dest->o_assignment = DEFINITELY_ASSIGNMENT;
+ 	}
+ 	goto again;
+ }
+ /*
+  * Scan input until EOF or end_trigger char.
+  * Return a list of pipes to execute, or NULL on EOF
+  * or if end_trigger character is met.
+  * On syntax error, exit is shell is not interactive,
+  * reset parsing machinery and start parsing anew,
+  * or return ERR_PTR.
+  */
+ static struct pipe *parse_stream(char **pstring,
+ 		struct in_str *input,
+ 		int end_trigger)
+ {
+ 	struct parse_context ctx;
+ 	o_string dest = NULL_O_STRING;
+ 	int is_in_dquote;
+ 	int heredoc_cnt;
+ 	/* Double-quote state is handled in the state variable is_in_dquote.
  	 * A single-quote triggers a bypass of the main loop until its mate is
- 	 * found.  When recursing, quote state is passed in via dest->o_quote. */
+ 	 * found.  When recursing, quote state is passed in via dest->o_escape.
+ 	 */
+ 	debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
+ 			end_trigger ? end_trigger : 'X');
+ 	debug_enter();
+ 	/* If very first arg is "" or '', dest.data may end up NULL.
+ 	 * Preventing this: */
+ 	o_addchr(&dest, '\0');
+ 	dest.length = 0;
- 	debug_printf_parse("parse_stream entered, end_trigger='%s' dest->o_assignment:%d\n", end_trigger, dest->o_assignment);
+ 	G.ifs = get_local_var_value("IFS");
+ 	if (G.ifs == NULL)
+ 		G.ifs = defifs;
+  reset:
+ #if ENABLE_HUSH_INTERACTIVE
+ 	input->promptmode = 0; /* PS1 */
+ #endif
+ 	/* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
+ 	initialize_context(&ctx);
+ 	is_in_dquote = 0;
+ 	heredoc_cnt = 0;
  	while (1) {
- 		m = CHAR_IFS;
+ 		const char *is_ifs;
- 		next = '\0';
+ 		const char *is_special;
+ 		int ch;
+ 		int next;
+ 		int redir_fd;
+ 		redir_type redir_style;
+ 		if (is_in_dquote) {
+ 			/* dest.o_quoted = 1; - already is (see below) */
+ 			if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
+ 				goto parse_error;
+ 			}
+ 			/* We reached closing '"' */
+ 			is_in_dquote = 0;
+ 		}
  		ch = i_getch(input);
- 		if (ch != EOF) {
+ 		debug_printf_parse(": ch=%c (%d) escape=%d\n",
- 			m = G.charmap[ch];
+ 						ch, ch, dest.o_escape);
- 			if (ch != '\n') {
+ 		if (ch == EOF) {
- 				next = i_peek(input);
+ 			struct pipe *pi;
+ 			if (heredoc_cnt) {
+ 				syntax_error_unterm_str("here document");
+ 				goto parse_error;
+ 			}
+ 			/* end_trigger == '}' case errors out earlier,
+ 			 * checking only ')' */
+ 			if (end_trigger == ')') {
+ 				syntax_error_unterm_ch('('); /* exits */
+ 				/* goto parse_error; */
+ 			}
+ 			if (done_word(&dest, &ctx)) {
+ 				goto parse_error;
+ 			}
+ 			o_free(&dest);
+ 			done_pipe(&ctx, PIPE_SEQ);
+ 			pi = ctx.list_head;
+ 			/* If we got nothing... */
+ 			/* (this makes bare "&" cmd a no-op.
+ 			 * bash says: "syntax error near unexpected token '&'") */
+ 			if (pi->num_cmds == 0
+ 			    IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
+ 			) {
+ 				free_pipe_list(pi);
+ 				pi = NULL;
  			}
+ #if !BB_MMU
+ 			debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
+ 			if (pstring)
+ 				*pstring = ctx.as_string.data;
+ 			else
+ 				o_free_unsafe(&ctx.as_string);
+ #endif
+ 			debug_leave();
+ 			debug_printf_parse("parse_stream return %p\n", pi);
+ 			return pi;
  		}
- 		debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
+ 		nommu_addchr(&ctx.as_string, ch);
- 						ch, ch, m, dest->o_quote);
- 		if (m == CHAR_ORDINARY
+ 		next = '\0';
- 		 || (m != CHAR_SPECIAL && shadow_quote)
+ 		if (ch != '\n')
+ 			next = i_peek(input);
+ 		is_special = "{}<>;&|()#'" /* special outside of "str" */
+ 				"\\$\"" IF_HUSH_TICK("`"); /* always special */
+ 		/* Are { and } special here? */
+ 		if (ctx.command->argv /* word [word]{... */
+ 		 || dest.length /* word{... */
+ 		 || dest.o_quoted /* ""{... */
+ 		 || (next != ';' && next != ')' && !strchr(G.ifs, next)) /* {word */
  		) {
- 			if (ch == EOF) {
+ 			/* They are not special, skip "{}" */
- 				syntax("unterminated \"");
+ 			is_special += 2;
- 				debug_printf_parse("parse_stream return 1: unterminated \"\n");
+ 		}
- 				return 1;
+ 		is_special = strchr(is_special, ch);
- 			}
+ 		is_ifs = strchr(G.ifs, ch);
- 			o_addQchr(dest, ch);
- 			if ((dest->o_assignment == MAYBE_ASSIGNMENT
+ 		if (!is_special && !is_ifs) { /* ordinary char */
- 			    || dest->o_assignment == WORD_IS_KEYWORD)
+  ordinary_char:
+ 			o_addQchr(&dest, ch);
+ 			if ((dest.o_assignment == MAYBE_ASSIGNMENT
+ 			    || dest.o_assignment == WORD_IS_KEYWORD)
  			 && ch == '='
- 			 && is_assignment(dest->data)
+ 			 && is_well_formed_var_name(dest.data, '=')
  			) {
- 				dest->o_assignment = DEFINITELY_ASSIGNMENT;
+ 				dest.o_assignment = DEFINITELY_ASSIGNMENT;
  			}
  			continue;
  		}
- 		if (m == CHAR_IFS) {
- 			if (done_word(dest, ctx)) {
+ 		if (is_ifs) {
- 				debug_printf_parse("parse_stream return 1: done_word!=0\n");
+ 			if (done_word(&dest, &ctx)) {
- 				return 1;
+ 				goto parse_error;
  			}
- 			if (ch == EOF)
+ 			if (ch == '\n') {
- 				break;
- 			/* If we aren't performing a substitution, treat
- 			 * a newline as a command separator.
- 			 * [why we don't handle it exactly like ';'? --vda] */
- 			if (end_trigger && ch == '\n') {
  #if ENABLE_HUSH_CASE
  				/* "case ... in <newline> word) ..." -
  				 * newlines are ignored (but ';' wouldn't be) */
- 				if (dest->length == 0 // && argv[0] == NULL
+ 				if (ctx.command->argv == NULL
- 				 && ctx->ctx_res_w == RES_MATCH
+ 				 && ctx.ctx_res_w == RES_MATCH
  				) {
  					continue;
  				}
  #endif
- 				done_pipe(ctx, PIPE_SEQ);
+ 				/* Treat newline as a command separator. */
- 				dest->o_assignment = MAYBE_ASSIGNMENT;
+ 				done_pipe(&ctx, PIPE_SEQ);
+ 				debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
+ 				if (heredoc_cnt) {
+ 					if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
+ 						goto parse_error;
+ 					}
+ 					heredoc_cnt = 0;
+ 				}
+ 				dest.o_assignment = MAYBE_ASSIGNMENT;
+ 				ch = ';';
+ 				/* note: if (is_ifs) continue;
+ 				 * will still trigger for us */
  			}
  		}
- 		if (end_trigger) {
- 			if (!shadow_quote && strchr(end_trigger, ch)) {
+ 		/* "cmd}" or "cmd }..." without semicolon or &:
- 				/* Special case: (...word) makes last word terminate,
+ 		 * } is an ordinary char in this case, even inside { cmd; }
- 				 * as if ';' is seen */
+ 		 * Pathological example: { ""}; } should exec "}" cmd
- 				if (ch == ')') {
+ 		 */
- 					done_word(dest, ctx);
+ 		if (ch == '}') {
- //err chk?
+ 			if (!IS_NULL_CMD(ctx.command) /* cmd } */
- 					done_pipe(ctx, PIPE_SEQ);
+ 			 || dest.length != 0 /* word} */
- 					dest->o_assignment = MAYBE_ASSIGNMENT;
+ 			 || dest.o_quoted    /* ""} */
- 				}
+ 			) {
- 				if (!HAS_KEYWORDS
+ 				goto ordinary_char;
- 				 IF_HAS_KEYWORDS(|| (ctx->ctx_res_w == RES_NONE && ctx->old_flag == 0))
+ 			}
- 				) {
+ 			if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
- 					debug_printf_parse("parse_stream return 0: end_trigger char found\n");
+ 				goto skip_end_trigger;
- 					return 0;
+ 			/* else: } does terminate a group */
- 				}
+ 		}
+ 		if (end_trigger && end_trigger == ch
+ 		 && (ch != ';' || heredoc_cnt == 0)
+ #if ENABLE_HUSH_CASE
+ 		 && (ch != ')'
+ 		    || ctx.ctx_res_w != RES_MATCH
+ 		    || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
+ 		    )
+ #endif
+ 		) {
+ 			if (heredoc_cnt) {
+ 				/* This is technically valid:
+ 				 * { cat <<HERE; }; echo Ok
+ 				 * heredoc
+ 				 * heredoc
+ 				 * HERE
+ 				 * but we don't support this.
+ 				 * We require heredoc to be in enclosing {}/(),
+ 				 * if any.
+ 				 */
+ 				syntax_error_unterm_str("here document");
+ 				goto parse_error;
+ 			}
+ 			if (done_word(&dest, &ctx)) {
+ 				goto parse_error;
+ 			}
+ 			done_pipe(&ctx, PIPE_SEQ);
+ 			dest.o_assignment = MAYBE_ASSIGNMENT;
+ 			/* Do we sit outside of any if's, loops or case's? */
+ 			if (!HAS_KEYWORDS
+ 			 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
+ 			) {
+ 				o_free(&dest);
+ #if !BB_MMU
+ 				debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
+ 				if (pstring)
+ 					*pstring = ctx.as_string.data;
+ 				else
+ 					o_free_unsafe(&ctx.as_string);
+ #endif
+ 				debug_leave();
+ 				debug_printf_parse("parse_stream return %p: "
+ 						"end_trigger char found\n",
+ 						ctx.list_head);
+ 				return ctx.list_head;
  			}
  		}
- 		if (m == CHAR_IFS)
+  skip_end_trigger:
+ 		if (is_ifs)
  			continue;
- 		if (dest->o_assignment == MAYBE_ASSIGNMENT) {
+ 		/* Catch <, > before deciding whether this word is
+ 		 * an assignment. a=1 2>z b=2: b=2 is still assignment */
+ 		switch (ch) {
+ 		case '>':
+ 			redir_fd = redirect_opt_num(&dest);
+ 			if (done_word(&dest, &ctx)) {
+ 				goto parse_error;
+ 			}
+ 			redir_style = REDIRECT_OVERWRITE;
+ 			if (next == '>') {
+ 				redir_style = REDIRECT_APPEND;
+ 				ch = i_getch(input);
+ 				nommu_addchr(&ctx.as_string, ch);
+ 			}
+ #if 0
+ 			else if (next == '(') {
+ 				syntax_error(">(process) not supported");
+ 				goto parse_error;
+ 			}
+ #endif
+ 			if (parse_redirect(&ctx, redir_fd, redir_style, input))
+ 				goto parse_error;
+ 			continue; /* back to top of while (1) */
+ 		case '<':
+ 			redir_fd = redirect_opt_num(&dest);
+ 			if (done_word(&dest, &ctx)) {
+ 				goto parse_error;
+ 			}
+ 			redir_style = REDIRECT_INPUT;
+ 			if (next == '<') {
+ 				redir_style = REDIRECT_HEREDOC;
+ 				heredoc_cnt++;
+ 				debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
+ 				ch = i_getch(input);
+ 				nommu_addchr(&ctx.as_string, ch);
+ 			} else if (next == '>') {
+ 				redir_style = REDIRECT_IO;
+ 				ch = i_getch(input);
+ 				nommu_addchr(&ctx.as_string, ch);
+ 			}
+ #if 0
+ 			else if (next == '(') {
+ 				syntax_error("<(process) not supported");
+ 				goto parse_error;
+ 			}
+ #endif
+ 			if (parse_redirect(&ctx, redir_fd, redir_style, input))
+ 				goto parse_error;
+ 			continue; /* back to top of while (1) */
+ 		}
+ 		if (dest.o_assignment == MAYBE_ASSIGNMENT
+ 		 /* check that we are not in word in "a=1 2>word b=1": */
+ 		 && !ctx.pending_redirect
+ 		) {
  			/* ch is a special char and thus this word
- 			 * cannot be an assignment: */
+ 			 * cannot be an assignment */
- 			dest->o_assignment = NOT_ASSIGNMENT;
+ 			dest.o_assignment = NOT_ASSIGNMENT;
  		}
+ 		/* Note: nommu_addchr(&ctx.as_string, ch) is already done */
  		switch (ch) {
  		case '#':
- 			if (dest->length == 0 && !shadow_quote) {
+ 			if (dest.length == 0) {
  				while (1) {
  					ch = i_peek(input);
  					if (ch == EOF || ch == '\n')
  						break;
  					i_getch(input);
+ 					/* note: we do not add it to &ctx.as_string */
  				}
+ 				nommu_addchr(&ctx.as_string, '\n');
  			} else {
- 				o_addQchr(dest, ch);
+ 				o_addQchr(&dest, ch);
  			}
  			break;
  		case '\\':
  			if (next == EOF) {
- 				syntax("\\<eof>");
+ 				syntax_error("\\<eof>");
- 				debug_printf_parse("parse_stream return 1: \\<eof>\n");
+ 				xfunc_die();
- 				return 1;
  			}
- 			/* bash:
+ 			ch = i_getch(input);
- 			 * "The backslash retains its special meaning [in "..."]
+ 			if (ch != '\n') {
- 			 * only when followed by one of the following characters:
+ 				o_addchr(&dest, '\\');
- 			 * $, `, ", \, or <newline>.  A double quote may be quoted
+ 				/*nommu_addchr(&ctx.as_string, '\\'); - already done */
- 			 * within double quotes by preceding it with a  backslash.
+ 				o_addchr(&dest, ch);
- 			 * If enabled, history expansion will be performed unless
+ 				nommu_addchr(&ctx.as_string, ch);
- 			 * an ! appearing in double quotes is escaped using
+ 				/* Example: echo Hello \2>file
- 			 * a backslash. The backslash preceding the ! is not removed."
+ 				 * we need to know that word 2 is quoted */
- 			 */
+ 				dest.o_quoted = 1;
- 			if (shadow_quote) { //NOT SURE   dest->o_quote) {
+ 			}
- 				if (strchr("$`\"\\", next) != NULL) {
+ #if !BB_MMU
- 					o_addqchr(dest, i_getch(input));
+ 			else {
- 				} else {
+ 				/* It's "\<newline>". Remove trailing '\' from ctx.as_string */
- 					o_addqchr(dest, '\\');
+ 				ctx.as_string.data[--ctx.as_string.length] = '\0';
- 				}
- 			} else {
- 				o_addchr(dest, '\\');
- 				o_addchr(dest, i_getch(input));
  			}
+ #endif
  			break;
  		case '$':
- 			if (handle_dollar(dest, input) != 0) {
+ 			if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
- 				debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
+ 				debug_printf_parse("parse_stream parse error: "
- 				return 1;
+ 					"handle_dollar returned non-0\n");
+ 				goto parse_error;
  			}
  			break;
  		case '\'':
- 			dest->nonnull = 1;
+ 			dest.o_quoted = 1;
  			while (1) {
  				ch = i_getch(input);
  				if (ch == EOF) {
- 					syntax("unterminated '");
+ 					syntax_error_unterm_ch('\'');
- 					debug_printf_parse("parse_stream return 1: unterminated '\n");
+ 					/*xfunc_die(); - redundant */
- 					return 1;
  				}
+ 				nommu_addchr(&ctx.as_string, ch);
  				if (ch == '\'')
  					break;
- 				if (dest->o_assignment == NOT_ASSIGNMENT)
+ 				o_addqchr(&dest, ch);
- 					o_addqchr(dest, ch);
- 				else
- 					o_addchr(dest, ch);
  			}
  			break;
  		case '"':
- 			dest->nonnull = 1;
+ 			dest.o_quoted = 1;
- 			shadow_quote ^= 1; /* invert */
+ 			is_in_dquote ^= 1; /* invert */
- 			if (dest->o_assignment == NOT_ASSIGNMENT)
+ 			if (dest.o_assignment == NOT_ASSIGNMENT)
- 				dest->o_quote ^= 1;
+ 				dest.o_escape ^= 1;
  			break;
  #if ENABLE_HUSH_TICK
  		case '`': {
- 			//int pos = dest->length;
+ #if !BB_MMU
- 			o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ 			int pos;
- 			o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`');
- 			add_till_backquote(dest, input);
- 			o_addchr(dest, SPECIAL_VAR_SYMBOL);
- 			//debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
- 			break;
- 		}
  #endif
- 		case '>':
+ 			o_addchr(&dest, SPECIAL_VAR_SYMBOL);
- 			redir_fd = redirect_opt_num(dest);
+ 			o_addchr(&dest, '`');
- 			done_word(dest, ctx);
+ #if !BB_MMU
- 			redir_style = REDIRECT_OVERWRITE;
+ 			pos = dest.length;
- 			if (next == '>') {
- 				redir_style = REDIRECT_APPEND;
- 				i_getch(input);
- 			}
- #if 0
- 			else if (next == '(') {
- 				syntax(">(process) not supported");
- 				debug_printf_parse("parse_stream return 1: >(process) not supported\n");
- 				return 1;
- 			}
  #endif
- 			setup_redirect(ctx, redir_fd, redir_style, input);
+ 			add_till_backquote(&dest, input);
- 			break;
+ #if !BB_MMU
- 		case '<':
+ 			o_addstr(&ctx.as_string, dest.data + pos);
- 			redir_fd = redirect_opt_num(dest);
+ 			o_addchr(&ctx.as_string, '`');
- 			done_word(dest, ctx);
- 			redir_style = REDIRECT_INPUT;
- 			if (next == '<') {
- 				redir_style = REDIRECT_HEREIS;
- 				i_getch(input);
- 			} else if (next == '>') {
- 				redir_style = REDIRECT_IO;
- 				i_getch(input);
- 			}
- #if 0
- 			else if (next == '(') {
- 				syntax("<(process) not supported");
- 				debug_printf_parse("parse_stream return 1: <(process) not supported\n");
- 				return 1;
- 			}
  #endif
- 			setup_redirect(ctx, redir_fd, redir_style, input);
+ 			o_addchr(&dest, SPECIAL_VAR_SYMBOL);
+ 			//debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
  			break;
+ 		}
+ #endif
  		case ';':
  #if ENABLE_HUSH_CASE
   case_semi:
  #endif
- 			done_word(dest, ctx);
+ 			if (done_word(&dest, &ctx)) {
- 			done_pipe(ctx, PIPE_SEQ);
+ 				goto parse_error;
+ 			}
+ 			done_pipe(&ctx, PIPE_SEQ);
  #if ENABLE_HUSH_CASE
  			/* Eat multiple semicolons, detect
  			 * whether it means something special */
-Line 3980 
 static int parse_stream(o_string *dest,
+Line 6514 
 static int parse_stream(o_string *dest,
  				ch = i_peek(input);
  				if (ch != ';')
  					break;
- 				i_getch(input);
+ 				ch = i_getch(input);
- 				if (ctx->ctx_res_w == RES_CASEI) {
+ 				nommu_addchr(&ctx.as_string, ch);
- 					ctx->ctx_dsemicolon = 1;
+ 				if (ctx.ctx_res_w == RES_CASE_BODY) {
- 					ctx->ctx_res_w = RES_MATCH;
+ 					ctx.ctx_dsemicolon = 1;
+ 					ctx.ctx_res_w = RES_MATCH;
  					break;
  				}
  			}
-Line 3991 
 static int parse_stream(o_string *dest,
+Line 6526 
 static int parse_stream(o_string *dest,
   new_cmd:
  			/* We just finished a cmd. New one may start
  			 * with an assignment */
- 			dest->o_assignment = MAYBE_ASSIGNMENT;
+ 			dest.o_assignment = MAYBE_ASSIGNMENT;
  			break;
  		case '&':
- 			done_word(dest, ctx);
+ 			if (done_word(&dest, &ctx)) {
+ 				goto parse_error;
+ 			}
  			if (next == '&') {
- 				i_getch(input);
+ 				ch = i_getch(input);
- 				done_pipe(ctx, PIPE_AND);
+ 				nommu_addchr(&ctx.as_string, ch);
+ 				done_pipe(&ctx, PIPE_AND);
  			} else {
- 				done_pipe(ctx, PIPE_BG);
+ 				done_pipe(&ctx, PIPE_BG);
  			}
  			goto new_cmd;
  		case '|':
- 			done_word(dest, ctx);
+ 			if (done_word(&dest, &ctx)) {
+ 				goto parse_error;
+ 			}
  #if ENABLE_HUSH_CASE
- 			if (ctx->ctx_res_w == RES_MATCH)
+ 			if (ctx.ctx_res_w == RES_MATCH)
  				break; /* we are in case's "word | word)" */
  #endif
  			if (next == '|') { /* || */
- 				i_getch(input);
+ 				ch = i_getch(input);
- 				done_pipe(ctx, PIPE_OR);
+ 				nommu_addchr(&ctx.as_string, ch);
+ 				done_pipe(&ctx, PIPE_OR);
  			} else {
  				/* we could pick up a file descriptor choice here
  				 * with redirect_opt_num(), but bash doesn't do it.
  				 * "echo foo 2| cat" yields "foo 2". */
- 				done_command(ctx);
+ 				done_command(&ctx);
+ #if !BB_MMU
+ 				o_reset_to_empty_unquoted(&ctx.as_string);
+ #endif
  			}
  			goto new_cmd;
  		case '(':
  #if ENABLE_HUSH_CASE
  			/* "case... in [(]word)..." - skip '(' */
- 			if (ctx->ctx_res_w == RES_MATCH
+ 			if (ctx.ctx_res_w == RES_MATCH
- 			 && ctx->command->argv == NULL /* not (word|(... */
+ 			 && ctx.command->argv == NULL /* not (word|(... */
- 			 && dest->length == 0 /* not word(... */
+ 			 && dest.length == 0 /* not word(... */
- 			 && dest->nonnull == 0 /* not ""(... */
+ 			 && dest.o_quoted == 0 /* not ""(... */
  			) {
  				continue;
  			}
  #endif
- #if ENABLE_HUSH_FUNCTIONS
- 			if (dest->length != 0 /* not just () but word() */
- 			 && dest->nonnull == 0 /* not a"b"c() */
- 			 && ctx->command->argv == NULL /* it's the first word */
- //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
- 			 && i_peek(input) == ')'
- 			 && !match_reserved_word(dest)
- 			) {
- 				bb_error_msg("seems like a function definition");
- 				i_getch(input);
- 				do {
- //TODO: do it properly.
- 					ch = i_getch(input);
- 				} while (ch == ' ' || ch == '\n');
- 				if (ch != '{') {
- 					syntax("was expecting {");
- 					debug_printf_parse("parse_stream return 1\n");
- 					return 1;
- 				}
- 				ch = 'F'; /* magic value */
- 			}
- #endif
  		case '{':
- 			if (parse_group(dest, ctx, input, ch) != 0) {
+ 			if (parse_group(&dest, &ctx, input, ch) != 0) {
- 				debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
+ 				goto parse_error;
- 				return 1;
  			}
  			goto new_cmd;
  		case ')':
  #if ENABLE_HUSH_CASE
- 			if (ctx->ctx_res_w == RES_MATCH)
+ 			if (ctx.ctx_res_w == RES_MATCH)
  				goto case_semi;
  #endif
  		case '}':
  			/* proper use of this character is caught by end_trigger:
  			 * if we see {, we call parse_group(..., end_trigger='}')
  			 * and it will match } earlier (not here). */
- 			syntax("unexpected } or )");
+ 			syntax_error_unexpected_ch(ch);
- 			debug_printf_parse("parse_stream return 1: unexpected '}'\n");
+ 			goto parse_error;
- 			return 1;
  		default:
  			if (HUSH_DEBUG)
  				bb_error_msg_and_die("BUG: unexpected %c\n", ch);
  		}
  	} /* while (1) */
- 	debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
- 	if (end_trigger)
- 		return -1;
- 	return 0;
- }
- static void set_in_charmap(const char *set, int code)
+  parse_error:
- {
+ 	{
- 	while (*set)
+ 		struct parse_context *pctx;
- 		G.charmap[(unsigned char)*set++] = code;
+ 		IF_HAS_KEYWORDS(struct parse_context *p2;)
- }
- static void update_charmap(void)
+ 		/* Clean up allocated tree.
- {
+ 		 * Sample for finding leaks on syntax error recovery path.
- 	G.ifs = getenv("IFS");
+ 		 * Run it from interactive shell, watch pmap `pidof hush`.
- 	if (G.ifs == NULL)
+ 		 * while if false; then false; fi; do break; fi
- 		G.ifs = " \t\n";
+ 		 * Samples to catch leaks at execution:
- 	/* Precompute a list of 'flow through' behavior so it can be treated
+ 		 * while if (true | {true;}); then echo ok; fi; do break; done
- 	 * quickly up front.  Computation is necessary because of IFS.
+ 		 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
- 	 * Special case handling of IFS == " \t\n" is not implemented.
+ 		 */
- 	 * The charmap[] array only really needs two bits each,
+ 		pctx = &ctx;
- 	 * and on most machines that would be faster (reduced L1 cache use).
+ 		do {
- 	 */
+ 			/* Update pipe/command counts,
- 	memset(G.charmap, CHAR_ORDINARY, sizeof(G.charmap));
+ 			 * otherwise freeing may miss some */
- #if ENABLE_HUSH_TICK
+ 			done_pipe(pctx, PIPE_SEQ);
- 	set_in_charmap("\\$\"`", CHAR_SPECIAL);
+ 			debug_printf_clean("freeing list %p from ctx %p\n",
- #else
+ 					pctx->list_head, pctx);
- 	set_in_charmap("\\$\"", CHAR_SPECIAL);
+ 			debug_print_tree(pctx->list_head, 0);
+ 			free_pipe_list(pctx->list_head);
+ 			debug_printf_clean("freed list %p\n", pctx->list_head);
+ #if !BB_MMU
+ 			o_free_unsafe(&pctx->as_string);
+ #endif
+ 			IF_HAS_KEYWORDS(p2 = pctx->stack;)
+ 			if (pctx != &ctx) {
+ 				free(pctx);
+ 			}
+ 			IF_HAS_KEYWORDS(pctx = p2;)
+ 		} while (HAS_KEYWORDS && pctx);
+ 		/* Free text, clear all dest fields */
+ 		o_free(&dest);
+ 		/* If we are not in top-level parse, we return,
+ 		 * our caller will propagate error.
+ 		 */
+ 		if (end_trigger != ';') {
+ #if !BB_MMU
+ 			if (pstring)
+ 				*pstring = NULL;
  #endif
- 	set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
+ 			debug_leave();
- 	set_in_charmap(G.ifs, CHAR_IFS);  /* are ordinary if quoted */
+ 			return ERR_PTR;
+ 		}
+ 		/* Discard cached input, force prompt */
+ 		input->p = NULL;
+ 		IF_HUSH_INTERACTIVE(input->promptme = 1;)
+ 		goto reset;
+ 	}
  }
- /* Most recursion does not come through here, the exception is
+ /* Executing from string: eval, sh -c '...'
-  * from builtin_source() and builtin_eval() */
+  *          or from file: /etc/profile, . file, sh <script>, sh (intereactive)
- static int parse_and_run_stream(struct in_str *inp, int parse_flag)
+  * end_trigger controls how often we stop parsing
+  * NUL: parse all, execute, return
+  * ';': parse till ';' or newline, execute, repeat till EOF
+  */
+ static void parse_and_run_stream(struct in_str *inp, int end_trigger)
  {
- 	struct parse_context ctx;
+ 	/* Why we need empty flag?
- 	o_string temp = NULL_O_STRING;
+ 	 * An obscure corner case "false; ``; echo $?":
- 	int rcode;
+ 	 * empty command in `` should still set $? to 0.
+ 	 * But we can't just set $? to 0 at the start,
+ 	 * this breaks "false; echo `echo $?`" case.
+ 	 */
+ 	bool empty = 1;
+ 	while (1) {
+ 		struct pipe *pipe_list;
- 	do {
+ 		pipe_list = parse_stream(NULL, inp, end_trigger);
- 		initialize_context(&ctx);
+ 		if (!pipe_list) { /* EOF */
- 		update_charmap();
+ 			if (empty)
- #if ENABLE_HUSH_INTERACTIVE
+ 				G.last_exitcode = 0;
- 		inp->promptmode = 0; /* PS1 */
+ 			break;
- #endif
- 		/* We will stop & execute after each ';' or '\n'.
- 		 * Example: "sleep 9999; echo TEST" + ctrl-C:
- 		 * TEST should be printed */
- 		temp.o_assignment = MAYBE_ASSIGNMENT;
- 		rcode = parse_stream(&temp, &ctx, inp, ";\n");
- #if HAS_KEYWORDS
- 		if (rcode != 1 && ctx.old_flag != 0) {
- 			syntax(NULL);
- 		}
- #endif
- 		if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) {
- 			done_word(&temp, &ctx);
- 			done_pipe(&ctx, PIPE_SEQ);
- 			debug_print_tree(ctx.list_head, 0);
- 			debug_printf_exec("parse_stream_outer: run_and_free_list\n");
- 			run_and_free_list(ctx.list_head);
- 		} else {
- 			/* We arrive here also if rcode == 1 (error in parse_stream) */
- #if HAS_KEYWORDS
- 			if (ctx.old_flag != 0) {
- 				free(ctx.stack);
- 				o_reset(&temp);
- 			}
- #endif
- 			/*temp.nonnull = 0; - o_free does it below */
- 			/*temp.o_quote = 0; - o_free does it below */
- 			free_pipe_list(ctx.list_head, /* indent: */ 0);
- 			/* Discard all unprocessed line input, force prompt on */
- 			inp->p = NULL;
- #if ENABLE_HUSH_INTERACTIVE
- 			inp->promptme = 1;
- #endif
  		}
- 		o_free(&temp);
+ 		debug_print_tree(pipe_list, 0);
- 		/* loop on syntax errors, return on EOF: */
+ 		debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
- 	} while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP));
+ 		run_and_free_list(pipe_list);
- 	return 0;
+ 		empty = 0;
+ 	}
  }
- static int parse_and_run_string(const char *s, int parse_flag)
+ static void parse_and_run_string(const char *s)
  {
  	struct in_str input;
  	setup_string_in_str(&input, s);
- 	return parse_and_run_stream(&input, parse_flag);
+ 	parse_and_run_stream(&input, '\0');
  }
- static int parse_and_run_file(FILE *f)
+ static void parse_and_run_file(FILE *f)
  {
- 	int rcode;
  	struct in_str input;
  	setup_file_in_str(&input, f);
- 	rcode = parse_and_run_stream(&input, 0 /* parse_flag */);
+ 	parse_and_run_stream(&input, ';');
- 	return rcode;
  }
- #if ENABLE_HUSH_JOB
+ /* Called a few times only (or even once if "sh -c") */
- /* Make sure we have a controlling tty.  If we get started under a job
+ static void init_sigmasks(void)
-  * aware app (like bash for example), make sure we are now in charge so
+ {
-  * we don't fight over who gets the foreground */
+ 	unsigned sig;
- static void setup_job_control(void)
+ 	unsigned mask;
- {
+ 	sigset_t old_blocked_set;
- 	pid_t shell_pgrp;
- 	shell_pgrp = getpgrp();
- 	close_on_exec_on(G.interactive_fd);
- 	/* If we were ran as 'hush &',
- 	 * sleep until we are in the foreground.  */
- 	while (tcgetpgrp(G.interactive_fd) != shell_pgrp) {
- 		/* Send TTIN to ourself (should stop us) */
- 		kill(- shell_pgrp, SIGTTIN);
- 		shell_pgrp = getpgrp();
- 	}
- 	/* Ignore job-control and misc signals.  */
- 	set_jobctrl_sighandler(SIG_IGN);
- 	set_misc_sighandler(SIG_IGN);
- //huh?	signal(SIGCHLD, SIG_IGN);
- 	/* We _must_ restore tty pgrp on fatal signals */
+ 	if (!G.inherited_set_is_saved) {
- 	set_fatal_sighandler(sigexit);
+ 		sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
+ 		G.inherited_set = G.blocked_set;
+ 	}
+ 	old_blocked_set = G.blocked_set;
+ 	mask = (1 << SIGQUIT);
+ 	if (G_interactive_fd) {
+ 		mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
+ 		if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
+ 			mask |= SPECIAL_JOB_SIGS;
+ 	}
+ 	G.non_DFL_mask = mask;
+ 	sig = 0;
+ 	while (mask) {
+ 		if (mask & 1)
+ 			sigaddset(&G.blocked_set, sig);
+ 		mask >>= 1;
+ 		sig++;
+ 	}
+ 	sigdelset(&G.blocked_set, SIGCHLD);
+ 	if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
+ 		sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+ 	/* POSIX allows shell to re-enable SIGCHLD
+ 	 * even if it was SIG_IGN on entry */
+ #if ENABLE_HUSH_FAST
+ 	G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
+ 	if (!G.inherited_set_is_saved)
+ 		signal(SIGCHLD, SIGCHLD_handler);
+ #else
+ 	if (!G.inherited_set_is_saved)
+ 		signal(SIGCHLD, SIG_DFL);
+ #endif
+ 	G.inherited_set_is_saved = 1;
+ }
- 	/* Put ourselves in our own process group.  */
+ #if ENABLE_HUSH_JOB
- 	bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
+ /* helper */
- 	/* Grab control of the terminal.  */
+ static void maybe_set_to_sigexit(int sig)
- 	tcsetpgrp(G.interactive_fd, getpid());
+ {
+ 	void (*handler)(int);
+ 	/* non_DFL_mask'ed signals are, well, masked,
+ 	 * no need to set handler for them.
+ 	 */
+ 	if (!((G.non_DFL_mask >> sig) & 1)) {
+ 		handler = signal(sig, sigexit);
+ 		if (handler == SIG_IGN) /* oops... restore back to IGN! */
+ 			signal(sig, handler);
+ 	}
+ }
+ /* Set handlers to restore tty pgrp and exit */
+ static void set_fatal_handlers(void)
+ {
+ 	/* We _must_ restore tty pgrp on fatal signals */
+ 	if (HUSH_DEBUG) {
+ 		maybe_set_to_sigexit(SIGILL );
+ 		maybe_set_to_sigexit(SIGFPE );
+ 		maybe_set_to_sigexit(SIGBUS );
+ 		maybe_set_to_sigexit(SIGSEGV);
+ 		maybe_set_to_sigexit(SIGTRAP);
+ 	} /* else: hush is perfect. what SEGV? */
+ 	maybe_set_to_sigexit(SIGABRT);
+ 	/* bash 3.2 seems to handle these just like 'fatal' ones */
+ 	maybe_set_to_sigexit(SIGPIPE);
+ 	maybe_set_to_sigexit(SIGALRM);
+ 	/* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
+ 	 * if we aren't interactive... but in this case
+ 	 * we never want to restore pgrp on exit, and this fn is not called */
+ 	/*maybe_set_to_sigexit(SIGHUP );*/
+ 	/*maybe_set_to_sigexit(SIGTERM);*/
+ 	/*maybe_set_to_sigexit(SIGINT );*/
  }
  #endif
+ static int set_mode(const char cstate, const char mode)
+ {
+ 	int state = (cstate == '-' ? 1 : 0);
+ 	switch (mode) {
+ 		case 'n': G.fake_mode = state; break;
+ 		case 'x': /*G.debug_mode = state;*/ break;
+ 		default:  return EXIT_FAILURE;
+ 	}
+ 	return EXIT_SUCCESS;
+ }
  int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  int hush_main(int argc, char **argv)
-Line 4221 
 int hush_main(int argc, char **argv)
+Line 6798 
 int hush_main(int argc, char **argv)
  		.flg_export = 1,
  		.flg_read_only = 1,
  	};
  	int opt;
- 	FILE *input;
+ 	unsigned builtin_argc;
  	char **e;
  	struct variable *cur_var;
  	INIT_G();
+ 	if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
- 	G.root_pid = getpid();
+ 		G.last_exitcode = EXIT_SUCCESS;
+ #if !BB_MMU
+ 	G.argv0_for_re_execing = argv[0];
+ #endif
  	/* Deal with HUSH_VERSION */
  	G.shell_ver = const_shell_ver; /* copying struct here */
  	G.top_var = &G.shell_ver;
-Line 4251 
 int hush_main(int argc, char **argv)
+Line 6829 
 int hush_main(int argc, char **argv)
  		}
  		e++;
  	}
+ 	/* reinstate HUSH_VERSION */
  	debug_printf_env("putenv '%s'\n", hush_version_str);
- 	putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
+ 	putenv((char *)hush_version_str);
+ 	/* Export PWD */
+ 	set_pwd_var(/*exp:*/ 1);
+ 	/* bash also exports SHLVL and _,
+ 	 * and sets (but doesn't export) the following variables:
+ 	 * BASH=/bin/bash
+ 	 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
+ 	 * BASH_VERSION='3.2.0(1)-release'
+ 	 * HOSTTYPE=i386
+ 	 * MACHTYPE=i386-pc-linux-gnu
+ 	 * OSTYPE=linux-gnu
+ 	 * HOSTNAME=<xxxxxxxxxx>
+ 	 * PPID=<NNNNN> - we also do it elsewhere
+ 	 * EUID=<NNNNN>
+ 	 * UID=<NNNNN>
+ 	 * GROUPS=()
+ 	 * LINES=<NNN>
+ 	 * COLUMNS=<NNN>
+ 	 * BASH_ARGC=()
+ 	 * BASH_ARGV=()
+ 	 * BASH_LINENO=()
+ 	 * BASH_SOURCE=()
+ 	 * DIRSTACK=()
+ 	 * PIPESTATUS=([0]="0")
+ 	 * HISTFILE=/<xxx>/.bash_history
+ 	 * HISTFILESIZE=500
+ 	 * HISTSIZE=500
+ 	 * MAILCHECK=60
+ 	 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
+ 	 * SHELL=/bin/bash
+ 	 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
+ 	 * TERM=dumb
+ 	 * OPTERR=1
+ 	 * OPTIND=1
+ 	 * IFS=$' \t\n'
+ 	 * PS1='\s-\v\$ '
+ 	 * PS2='> '
+ 	 * PS4='+ '
+ 	 */
  #if ENABLE_FEATURE_EDITING
  	G.line_input_state = new_line_input_t(FOR_SHELL);
  #endif
- 	/* XXX what should these be while sourcing /etc/profile? */
  	G.global_argc = argc;
  	G.global_argv = argv;
  	/* Initialize some more globals to non-zero values */
- 	set_cwd();
+ 	cmdedit_update_prompt();
- #if ENABLE_HUSH_INTERACTIVE
- #if ENABLE_FEATURE_EDITING
- 	cmdedit_set_initial_prompt();
- #endif
- 	G.PS2 = "> ";
- #endif
- 	if (EXIT_SUCCESS) /* otherwise is already done */
- 		G.last_return_code = EXIT_SUCCESS;
- 	if (argv[0] && argv[0][0] == '-') {
+ 	if (setjmp(die_jmp)) {
- 		debug_printf("sourcing /etc/profile\n");
+ 		/* xfunc has failed! die die die */
- 		input = fopen_for_read("/etc/profile");
+ 		/* no EXIT traps, this is an escape hatch! */
- 		if (input != NULL) {
+ 		G.exiting = 1;
- 			close_on_exec_on(fileno(input));
+ 		hush_exit(xfunc_error_retval);
- 			parse_and_run_file(input);
- 			fclose(input);
- 		}
  	}
- 	input = stdin;
- 	while ((opt = getopt(argc, argv, "c:xif")) > 0) {
+ 	/* Shell is non-interactive at first. We need to call
+ 	 * init_sigmasks() if we are going to execute "sh <script>",
+ 	 * "sh -c <cmds>" or login shell's /etc/profile and friends.
+ 	 * If we later decide that we are interactive, we run init_sigmasks()
+ 	 * in order to intercept (more) signals.
+ 	 */
+ 	/* Parse options */
+ 	/* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
+ 	builtin_argc = 0;
+ 	while (1) {
+ 		opt = getopt(argc, argv, "+c:xins"
+ #if !BB_MMU
+ 				"<:$:R:V:"
+ # if ENABLE_HUSH_FUNCTIONS
+ 				"F:"
+ # endif
+ #endif
+ 		);
+ 		if (opt <= 0)
+ 			break;
  		switch (opt) {
  		case 'c':
+ 			/* Possibilities:
+ 			 * sh ... -c 'script'
+ 			 * sh ... -c 'script' ARG0 [ARG1...]
+ 			 * On NOMMU, if builtin_argc != 0,
+ 			 * sh ... -c 'builtin' [BARGV...] "" ARG0 [ARG1...]
+ 			 * "" needs to be replaced with NULL
+ 			 * and BARGV vector fed to builtin function.
+ 			 * Note: this form never happens:
+ 			 * sh ... -c 'builtin' [BARGV...] ""
+ 			 */
+ 			if (!G.root_pid) {
+ 				G.root_pid = getpid();
+ 				G.root_ppid = getppid();
+ 			}
  			G.global_argv = argv + optind;
- 			if (!argv[optind]) {
- 				/* -c 'script' (no params): prevent empty $0 */
- 				*--G.global_argv = argv[0];
- 				optind--;
- 			} /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
  			G.global_argc = argc - optind;
- 			opt = parse_and_run_string(optarg, 0 /* parse_flag */);
+ 			if (builtin_argc) {
+ 				/* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
+ 				const struct built_in_command *x;
+ 				init_sigmasks();
+ 				x = find_builtin(optarg);
+ 				if (x) { /* paranoia */
+ 					G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
+ 					G.global_argv += builtin_argc;
+ 					G.global_argv[-1] = NULL; /* replace "" */
+ 					G.last_exitcode = x->function(argv + optind - 1);
+ 				}
+ 				goto final_return;
+ 			}
+ 			if (!G.global_argv[0]) {
+ 				/* -c 'script' (no params): prevent empty $0 */
+ 				G.global_argv--; /* points to argv[i] of 'script' */
+ 				G.global_argv[0] = argv[0];
+ 				G.global_argc--;
+ 			} /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
+ 			init_sigmasks();
+ 			parse_and_run_string(optarg);
  			goto final_return;
  		case 'i':
  			/* Well, we cannot just declare interactiveness,
  			 * we have to have some stuff (ctty, etc) */
- 			/* G.interactive_fd++; */
+ 			/* G_interactive_fd++; */
  			break;
- 		case 'f':
+ 		case 's':
- 			G.fake_mode = 1;
+ 			/* "-s" means "read from stdin", but this is how we always
+ 			 * operate, so simply do nothing here. */
  			break;
+ #if !BB_MMU
+ 		case '<': /* "big heredoc" support */
+ 			full_write(STDOUT_FILENO, optarg, strlen(optarg));
+ 			_exit(0);
+ 		case '$': {
+ 			unsigned long long empty_trap_mask;
+ 			G.root_pid = bb_strtou(optarg, &optarg, 16);
+ 			optarg++;
+ 			G.root_ppid = bb_strtou(optarg, &optarg, 16);
+ 			optarg++;
+ 			G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
+ 			optarg++;
+ 			G.last_exitcode = bb_strtou(optarg, &optarg, 16);
+ 			optarg++;
+ 			builtin_argc = bb_strtou(optarg, &optarg, 16);
+ 			optarg++;
+ 			empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
+ 			if (empty_trap_mask != 0) {
+ 				int sig;
+ 				init_sigmasks();
+ 				G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
+ 				for (sig = 1; sig < NSIG; sig++) {
+ 					if (empty_trap_mask & (1LL << sig)) {
+ 						G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
+ 						sigaddset(&G.blocked_set, sig);
+ 					}
+ 				}
+ 				sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+ 			}
+ # if ENABLE_HUSH_LOOPS
+ 			optarg++;
+ 			G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
+ # endif
+ 			break;
+ 		}
+ 		case 'R':
+ 		case 'V':
+ 			set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
+ 			break;
+ # if ENABLE_HUSH_FUNCTIONS
+ 		case 'F': {
+ 			struct function *funcp = new_function(optarg);
+ 			/* funcp->name is already set to optarg */
+ 			/* funcp->body is set to NULL. It's a special case. */
+ 			funcp->body_as_string = argv[optind];
+ 			optind++;
+ 			break;
+ 		}
+ # endif
+ #endif
+ 		case 'n':
+ 		case 'x':
+ 			if (!set_mode('-', opt))
+ 				break;
  		default:
  #ifndef BB_VER
  			fprintf(stderr, "Usage: sh [FILE]...\n"
-Line 4312 
 int hush_main(int argc, char **argv)
+Line 7022 
 int hush_main(int argc, char **argv)
  			bb_show_usage();
  #endif
  		}
+ 	} /* option parsing loop */
+ 	if (!G.root_pid) {
+ 		G.root_pid = getpid();
+ 		G.root_ppid = getppid();
  	}
- #if ENABLE_HUSH_JOB
- 	/* A shell is interactive if the '-i' flag was given, or if all of
+ 	/* If we are login shell... */
- 	 * the following conditions are met:
+ 	if (argv[0] && argv[0][0] == '-') {
+ 		FILE *input;
+ 		debug_printf("sourcing /etc/profile\n");
+ 		input = fopen_for_read("/etc/profile");
+ 		if (input != NULL) {
+ 			close_on_exec_on(fileno(input));
+ 			init_sigmasks();
+ 			parse_and_run_file(input);
+ 			fclose(input);
+ 		}
+ 		/* bash: after sourcing /etc/profile,
+ 		 * tries to source (in the given order):
+ 		 * ~/.bash_profile, ~/.bash_login, ~/.profile,
+ 		 * stopping on first found. --noprofile turns this off.
+ 		 * bash also sources ~/.bash_logout on exit.
+ 		 * If called as sh, skips .bash_XXX files.
+ 		 */
+ 	}
+ 	if (argv[optind]) {
+ 		FILE *input;
+ 		/*
+ 		 * "bash <script>" (which is never interactive (unless -i?))
+ 		 * sources $BASH_ENV here (without scanning $PATH).
+ 		 * If called as sh, does the same but with $ENV.
+ 		 */
+ 		debug_printf("running script '%s'\n", argv[optind]);
+ 		G.global_argv = argv + optind;
+ 		G.global_argc = argc - optind;
+ 		input = xfopen_for_read(argv[optind]);
+ 		close_on_exec_on(fileno(input));
+ 		init_sigmasks();
+ 		parse_and_run_file(input);
+ #if ENABLE_FEATURE_CLEAN_UP
+ 		fclose(input);
+ #endif
+ 		goto final_return;
+ 	}
+ 	/* Up to here, shell was non-interactive. Now it may become one.
+ 	 * NB: don't forget to (re)run init_sigmasks() as needed.
+ 	 */
+ 	/* A shell is interactive if the '-i' flag was given,
+ 	 * or if all of the following conditions are met:
  	 *    no -c command
  	 *    no arguments remaining or the -s flag given
  	 *    standard input is a terminal
  	 *    standard output is a terminal
- 	 *    Refer to Posix.2, the description of the 'sh' utility. */
+ 	 * Refer to Posix.2, the description of the 'sh' utility.
- 	if (argv[optind] == NULL && input == stdin
+ 	 */
- 	 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
+ #if ENABLE_HUSH_JOB
- 	) {
+ 	if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
- 		G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
+ 		G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
- 		debug_printf("saved_tty_pgrp=%d\n", G.saved_tty_pgrp);
+ 		debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
- 		if (G.saved_tty_pgrp >= 0) {
+ 		if (G_saved_tty_pgrp < 0)
- 			/* try to dup to high fd#, >= 255 */
+ 			G_saved_tty_pgrp = 0;
- 			G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
- 			if (G.interactive_fd < 0) {
+ 		/* try to dup stdin to high fd#, >= 255 */
- 				/* try to dup to any fd */
+ 		G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
- 				G.interactive_fd = dup(STDIN_FILENO);
+ 		if (G_interactive_fd < 0) {
- 				if (G.interactive_fd < 0)
+ 			/* try to dup to any fd */
- 					/* give up */
+ 			G_interactive_fd = dup(STDIN_FILENO);
- 					G.interactive_fd = 0;
+ 			if (G_interactive_fd < 0) {
- 			}
+ 				/* give up */
- 			// TODO: track & disallow any attempts of user
+ 				G_interactive_fd = 0;
- 			// to (inadvertently) close/redirect it
+ 				G_saved_tty_pgrp = 0;
- 		}
+ 			}
- 	}
+ 		}
- 	debug_printf("G.interactive_fd=%d\n", G.interactive_fd);
+ // TODO: track & disallow any attempts of user
- 	if (G.interactive_fd) {
+ // to (inadvertently) close/redirect G_interactive_fd
- 		fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
+ 	}
- 		/* Looks like they want an interactive shell */
+ 	debug_printf("interactive_fd:%d\n", G_interactive_fd);
- 		setup_job_control();
+ 	if (G_interactive_fd) {
+ 		close_on_exec_on(G_interactive_fd);
+ 		if (G_saved_tty_pgrp) {
+ 			/* If we were run as 'hush &', sleep until we are
+ 			 * in the foreground (tty pgrp == our pgrp).
+ 			 * If we get started under a job aware app (like bash),
+ 			 * make sure we are now in charge so we don't fight over
+ 			 * who gets the foreground */
+ 			while (1) {
+ 				pid_t shell_pgrp = getpgrp();
+ 				G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
+ 				if (G_saved_tty_pgrp == shell_pgrp)
+ 					break;
+ 				/* send TTIN to ourself (should stop us) */
+ 				kill(- shell_pgrp, SIGTTIN);
+ 			}
+ 		}
+ 		/* Block some signals */
+ 		init_sigmasks();
+ 		if (G_saved_tty_pgrp) {
+ 			/* Set other signals to restore saved_tty_pgrp */
+ 			set_fatal_handlers();
+ 			/* Put ourselves in our own process group
+ 			 * (bash, too, does this only if ctty is available) */
+ 			bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
+ 			/* Grab control of the terminal */
+ 			tcsetpgrp(G_interactive_fd, getpid());
+ 		}
  		/* -1 is special - makes xfuncs longjmp, not exit
  		 * (we reset die_sleep = 0 whereever we [v]fork) */
- 		die_sleep = -1;
+ 		enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
- 		if (setjmp(die_jmp)) {
+ 	} else {
- 			/* xfunc has failed! die die die */
+ 		init_sigmasks();
- 			hush_exit(xfunc_error_retval);
- 		}
- #if !ENABLE_FEATURE_SH_EXTRA_QUIET
- 		printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
- 		printf("Enter 'help' for a list of built-in commands.\n\n");
- #endif
  	}
  #elif ENABLE_HUSH_INTERACTIVE
- /* no job control compiled, only prompt/line editing */
+ 	/* No job control compiled in, only prompt/line editing */
- 	if (argv[optind] == NULL && input == stdin
+ 	if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
- 	 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
+ 		G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
- 	) {
+ 		if (G_interactive_fd < 0) {
- 		G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
- 		if (G.interactive_fd < 0) {
  			/* try to dup to any fd */
- 			G.interactive_fd = dup(STDIN_FILENO);
+ 			G_interactive_fd = dup(STDIN_FILENO);
- 			if (G.interactive_fd < 0)
+ 			if (G_interactive_fd < 0)
  				/* give up */
- 				G.interactive_fd = 0;
+ 				G_interactive_fd = 0;
- 		}
- 		if (G.interactive_fd) {
- 			fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
- 			set_misc_sighandler(SIG_IGN);
  		}
  	}
+ 	if (G_interactive_fd) {
+ 		close_on_exec_on(G_interactive_fd);
+ 	}
+ 	init_sigmasks();
+ #else
+ 	/* We have interactiveness code disabled */
+ 	init_sigmasks();
  #endif
+ 	/* bash:
+ 	 * if interactive but not a login shell, sources ~/.bashrc
+ 	 * (--norc turns this off, --rcfile <file> overrides)
+ 	 */
- 	if (argv[optind] == NULL) {
+ 	if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
- 		opt = parse_and_run_file(stdin);
+ 		/* note: ash and hush share this string */
- 	} else {
+ 		printf("\n\n%s %s\n"
- 		debug_printf("\nrunning script '%s'\n", argv[optind]);
+ 			IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
- 		G.global_argv = argv + optind;
+ 			"\n",
- 		G.global_argc = argc - optind;
+ 			bb_banner,
- 		input = xfopen_for_read(argv[optind]);
+ 			"hush - the humble shell"
- 		fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
+ 		);
- 		opt = parse_and_run_file(input);
  	}
-  final_return:
+ 	parse_and_run_file(stdin);
+  final_return:
  #if ENABLE_FEATURE_CLEAN_UP
- 	fclose(input);
  	if (G.cwd != bb_msg_unknown)
  		free((char*)G.cwd);
  	cur_var = G.top_var->next;
-Line 4403 
 int hush_main(int argc, char **argv)
+Line 7190 
 int hush_main(int argc, char **argv)
  		free(tmp);
  	}
  #endif
- 	hush_exit(opt ? opt : G.last_return_code);
+ 	hush_exit(G.last_exitcode);
  }
-Line 4411 
 int hush_main(int argc, char **argv)
+Line 7198 
 int hush_main(int argc, char **argv)
  int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  int lash_main(int argc, char **argv)
  {
- 	//bb_error_msg("lash is deprecated, please use hush instead");
+ 	bb_error_msg("lash is deprecated, please use hush instead");
+ 	return hush_main(argc, argv);
+ }
+ #endif
+ #if ENABLE_MSH
+ int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+ int msh_main(int argc, char **argv)
+ {
+ 	//bb_error_msg("msh is deprecated, please use hush instead");
  	return hush_main(argc, argv);
  }
  #endif
-Line 4420 
 int lash_main(int argc, char **argv)
+Line 7216 
 int lash_main(int argc, char **argv)
  /*
   * Built-ins
   */
- static int builtin_true(char **argv UNUSED_PARAM)
+ static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
  {
  	return 0;
  }
- static int builtin_test(char **argv)
+ static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
  {
  	int argc = 0;
  	while (*argv) {
  		argc++;
  		argv++;
  	}
- 	return test_main(argc, argv - argc);
+ 	return applet_main_func(argc, argv - argc);
  }
- static int builtin_echo(char **argv)
+ static int FAST_FUNC builtin_test(char **argv)
  {
- 	int argc = 0;
+ 	return run_applet_main(argv, test_main);
- 	while (*argv) {
+ }
- 		argc++;
- 		argv++;
+ static int FAST_FUNC builtin_echo(char **argv)
- 	}
+ {
- 	return echo_main(argc, argv - argc);
+ 	return run_applet_main(argv, echo_main);
+ }
+ #if ENABLE_PRINTF
+ static int FAST_FUNC builtin_printf(char **argv)
+ {
+ 	return run_applet_main(argv, printf_main);
  }
+ #endif
- static int builtin_eval(char **argv)
+ static int FAST_FUNC builtin_eval(char **argv)
  {
  	int rcode = EXIT_SUCCESS;
- 	if (argv[1]) {
+ 	if (*++argv) {
- 		char *str = expand_strvec_to_string(argv + 1);
+ 		char *str = expand_strvec_to_string(argv);
- 		parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP);
+ 		/* bash:
+ 		 * eval "echo Hi; done" ("done" is syntax error):
+ 		 * "echo Hi" will not execute too.
+ 		 */
+ 		parse_and_run_string(str);
  		free(str);
- 		rcode = G.last_return_code;
+ 		rcode = G.last_exitcode;
  	}
  	return rcode;
  }
- static int builtin_cd(char **argv)
+ static int FAST_FUNC builtin_cd(char **argv)
  {
- 	const char *newdir;
+ 	const char *newdir = argv[1];
- 	if (argv[1] == NULL) {
+ 	if (newdir == NULL) {
- 		// bash does nothing (exitcode 0) if HOME is ""; if it's unset,
+ 		/* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
- 		// bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
+ 		 * bash says "bash: cd: HOME not set" and does nothing
- 		newdir = getenv("HOME") ? : "/";
+ 		 * (exitcode 1)
- 	} else
+ 		 */
- 		newdir = argv[1];
+ 		const char *home = get_local_var_value("HOME");
+ 		newdir = home ? home : "/";
+ 	}
  	if (chdir(newdir)) {
- 		printf("cd: %s: %s\n", newdir, strerror(errno));
+ 		/* Mimic bash message exactly */
+ 		bb_perror_msg("cd: %s", newdir);
  		return EXIT_FAILURE;
  	}
- 	set_cwd();
+ 	/* Read current dir (get_cwd(1) is inside) and set PWD.
+ 	 * Note: do not enforce exporting. If PWD was unset or unexported,
+ 	 * set it again, but do not export. bash does the same.
+ 	 */
+ 	set_pwd_var(/*exp:*/ 0);
  	return EXIT_SUCCESS;
  }
- static int builtin_exec(char **argv)
+ static int FAST_FUNC builtin_exec(char **argv)
  {
- 	if (argv[1] == NULL)
+ 	if (*++argv == NULL)
  		return EXIT_SUCCESS; /* bash does this */
- 	{
- #if !BB_MMU
+ 	/* Careful: we can end up here after [v]fork. Do not restore
- 		nommu_save_t dummy;
+ 	 * tty pgrp then, only top-level shell process does that */
- #endif
+ 	if (G_saved_tty_pgrp && getpid() == G.root_pid)
- // FIXME: if exec fails, bash does NOT exit! We do...
+ 		tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
- 		pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
- 		/* never returns */
+ 	/* TODO: if exec fails, bash does NOT exit! We do.
- 	}
+ 	 * We'll need to undo sigprocmask (it's inside execvp_or_die)
+ 	 * and tcsetpgrp, and this is inherently racy.
+ 	 */
+ 	execvp_or_die(argv);
  }
- static int builtin_exit(char **argv)
+ static int FAST_FUNC builtin_exit(char **argv)
  {
- // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
+ 	debug_printf_exec("%s()\n", __func__);
- 	//puts("exit"); /* bash does it */
- // TODO: warn if we have background jobs: "There are stopped jobs"
+ 	/* interactive bash:
- // On second consecutive 'exit', exit anyway.
+ 	 * # trap "echo EEE" EXIT
- 	if (argv[1] == NULL)
+ 	 * # exit
- 		hush_exit(G.last_return_code);
+ 	 * exit
+ 	 * There are stopped jobs.
+ 	 * (if there are _stopped_ jobs, running ones don't count)
+ 	 * # exit
+ 	 * exit
+ 	 # EEE (then bash exits)
+ 	 *
+ 	 * we can use G.exiting = -1 as indicator "last cmd was exit"
+ 	 */
+ 	/* note: EXIT trap is run by hush_exit */
+ 	if (*++argv == NULL)
+ 		hush_exit(G.last_exitcode);
  	/* mimic bash: exit 123abc == exit 255 + error msg */
  	xfunc_error_retval = 255;
  	/* bash: exit -2 == exit 254, no error msg */
- 	hush_exit(xatoi(argv[1]) & 0xff);
+ 	hush_exit(xatoi(*argv) & 0xff);
  }
- static int builtin_export(char **argv)
+ static void print_escaped(const char *s)
  {
- 	const char *value;
+ 	if (*s == '\'')
- 	char *name = argv[1];
+ 		goto squote;
+ 	do {
+ 		const char *p = strchrnul(s, '\'');
+ 		/* print 'xxxx', possibly just '' */
+ 		printf("'%.*s'", (int)(p - s), s);
+ 		if (*p == '\0')
+ 			break;
+ 		s = p;
+  squote:
+ 		/* s points to '; print "'''...'''" */
+ 		putchar('"');
+ 		do putchar('\''); while (*++s == '\'');
+ 		putchar('"');
+ 	} while (*s);
+ }
+ #if !ENABLE_HUSH_LOCAL
+ #define helper_export_local(argv, exp, lvl) \
+ 	helper_export_local(argv, exp)
+ #endif
+ static void helper_export_local(char **argv, int exp, int lvl)
+ {
+ 	do {
+ 		char *name = *argv;
+ 		/* So far we do not check that name is valid (TODO?) */
+ 		if (strchr(name, '=') == NULL) {
+ 			struct variable *var;
+ 			var = get_local_var(name);
+ 			if (exp == -1) { /* unexporting? */
+ 				/* export -n NAME (without =VALUE) */
+ 				if (var) {
+ 					var->flg_export = 0;
+ 					debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
+ 					unsetenv(name);
+ 				} /* else: export -n NOT_EXISTING_VAR: no-op */
+ 				continue;
+ 			}
+ 			if (exp == 1) { /* exporting? */
+ 				/* export NAME (without =VALUE) */
+ 				if (var) {
+ 					var->flg_export = 1;
+ 					debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
+ 					putenv(var->varstr);
+ 					continue;
+ 				}
+ 			}
+ 			/* Exporting non-existing variable.
+ 			 * bash does not put it in environment,
+ 			 * but remembers that it is exported,
+ 			 * and does put it in env when it is set later.
+ 			 * We just set it to "" and export. */
+ 			/* Or, it's "local NAME" (without =VALUE).
+ 			 * bash sets the value to "". */
+ 			name = xasprintf("%s=", name);
+ 		} else {
+ 			/* (Un)exporting/making local NAME=VALUE */
+ 			name = xstrdup(name);
+ 		}
+ 		set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
+ 	} while (*++argv);
+ }
+ static int FAST_FUNC builtin_export(char **argv)
+ {
+ 	unsigned opt_unexport;
+ #if ENABLE_HUSH_EXPORT_N
+ 	/* "!": do not abort on errors */
+ 	opt_unexport = getopt32(argv, "!n");
+ 	if (opt_unexport == (uint32_t)-1)
+ 		return EXIT_FAILURE;
+ 	argv += optind;
+ #else
+ 	opt_unexport = 0;
+ 	argv++;
+ #endif
- 	if (name == NULL) {
+ 	if (argv[0] == NULL) {
- 		// TODO:
- 		// ash emits: export VAR='VAL'
- 		// bash: declare -x VAR="VAL"
- 		// (both also escape as needed (quotes, $, etc))
  		char **e = environ;
- 		if (e)
+ 		if (e) {
- 			while (*e)
+ 			while (*e) {
+ #if 0
  				puts(*e++);
+ #else
+ 				/* ash emits: export VAR='VAL'
+ 				 * bash: declare -x VAR="VAL"
+ 				 * we follow ash example */
+ 				const char *s = *e++;
+ 				const char *p = strchr(s, '=');
+ 				if (!p) /* wtf? take next variable */
+ 					continue;
+ 				/* export var= */
+ 				printf("export %.*s", (int)(p - s) + 1, s);
+ 				print_escaped(p + 1);
+ 				putchar('\n');
+ #endif
+ 			}
+ 			/*fflush_all(); - done after each builtin anyway */
+ 		}
  		return EXIT_SUCCESS;
  	}
- 	value = strchr(name, '=');
+ 	helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
- 	if (!value) {
- 		/* They are exporting something without a =VALUE */
- 		struct variable *var;
- 		var = get_local_var(name);
+ 	return EXIT_SUCCESS;
- 		if (var) {
+ }
- 			var->flg_export = 1;
- 			debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
+ #if ENABLE_HUSH_LOCAL
- 			putenv(var->varstr);
+ static int FAST_FUNC builtin_local(char **argv)
+ {
+ 	if (G.func_nest_level == 0) {
+ 		bb_error_msg("%s: not in a function", argv[0]);
+ 		return EXIT_FAILURE; /* bash compat */
+ 	}
+ 	helper_export_local(argv, 0, G.func_nest_level);
+ 	return EXIT_SUCCESS;
+ }
+ #endif
+ static int FAST_FUNC builtin_trap(char **argv)
+ {
+ 	int sig;
+ 	char *new_cmd;
+ 	if (!G.traps)
+ 		G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
+ 	argv++;
+ 	if (!*argv) {
+ 		int i;
+ 		/* No args: print all trapped */
+ 		for (i = 0; i < NSIG; ++i) {
+ 			if (G.traps[i]) {
+ 				printf("trap -- ");
+ 				print_escaped(G.traps[i]);
+ 				/* note: bash adds "SIG", but only if invoked
+ 				 * as "bash". If called as "sh", or if set -o posix,
+ 				 * then it prints short signal names.
+ 				 * We are printing short names: */
+ 				printf(" %s\n", get_signame(i));
+ 			}
  		}
- 		/* bash does not return an error when trying to export
+ 		/*fflush_all(); - done after each builtin anyway */
- 		 * an undefined variable.  Do likewise. */
  		return EXIT_SUCCESS;
  	}
- 	set_local_var(xstrdup(name), 1);
+ 	new_cmd = NULL;
- 	return EXIT_SUCCESS;
+ 	/* If first arg is a number: reset all specified signals */
+ 	sig = bb_strtou(*argv, NULL, 10);
+ 	if (errno == 0) {
+ 		int ret;
+  process_sig_list:
+ 		ret = EXIT_SUCCESS;
+ 		while (*argv) {
+ 			sig = get_signum(*argv++);
+ 			if (sig < 0 || sig >= NSIG) {
+ 				ret = EXIT_FAILURE;
+ 				/* Mimic bash message exactly */
+ 				bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
+ 				continue;
+ 			}
+ 			free(G.traps[sig]);
+ 			G.traps[sig] = xstrdup(new_cmd);
+ 			debug_printf("trap: setting SIG%s (%i) to '%s'\n",
+ 				get_signame(sig), sig, G.traps[sig]);
+ 			/* There is no signal for 0 (EXIT) */
+ 			if (sig == 0)
+ 				continue;
+ 			if (new_cmd) {
+ 				sigaddset(&G.blocked_set, sig);
+ 			} else {
+ 				/* There was a trap handler, we are removing it
+ 				 * (if sig has non-DFL handling,
+ 				 * we don't need to do anything) */
+ 				if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
+ 					continue;
+ 				sigdelset(&G.blocked_set, sig);
+ 			}
+ 		}
+ 		sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+ 		return ret;
+ 	}
+ 	if (!argv[1]) { /* no second arg */
+ 		bb_error_msg("trap: invalid arguments");
+ 		return EXIT_FAILURE;
+ 	}
+ 	/* First arg is "-": reset all specified to default */
+ 	/* First arg is "--": skip it, the rest is "handler SIGs..." */
+ 	/* Everything else: set arg as signal handler
+ 	 * (includes "" case, which ignores signal) */
+ 	if (argv[0][0] == '-') {
+ 		if (argv[0][1] == '\0') { /* "-" */
+ 			/* new_cmd remains NULL: "reset these sigs" */
+ 			goto reset_traps;
+ 		}
+ 		if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
+ 			argv++;
+ 		}
+ 		/* else: "-something", no special meaning */
+ 	}
+ 	new_cmd = *argv;
+  reset_traps:
+ 	argv++;
+ 	goto process_sig_list;
+ }
+ /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
+ static int FAST_FUNC builtin_type(char **argv)
+ {
+ 	int ret = EXIT_SUCCESS;
+ 	while (*++argv) {
+ 		const char *type;
+ 		char *path = NULL;
+ 		if (0) {} /* make conditional compile easier below */
+ 		/*else if (find_alias(*argv))
+ 			type = "an alias";*/
+ #if ENABLE_HUSH_FUNCTIONS
+ 		else if (find_function(*argv))
+ 			type = "a function";
+ #endif
+ 		else if (find_builtin(*argv))
+ 			type = "a shell builtin";
+ 		else if ((path = find_in_path(*argv)) != NULL)
+ 			type = path;
+ 		else {
+ 			bb_error_msg("type: %s: not found", *argv);
+ 			ret = EXIT_FAILURE;
+ 			continue;
+ 		}
+ 		printf("%s is %s\n", *argv, type);
+ 		free(path);
+ 	}
+ 	return ret;
  }
  #if ENABLE_HUSH_JOB
  /* built-in 'fg' and 'bg' handler */
- static int builtin_fg_bg(char **argv)
+ static int FAST_FUNC builtin_fg_bg(char **argv)
  {
  	int i, jobnum;
  	struct pipe *pi;
- 	if (!G.interactive_fd)
+ 	if (!G_interactive_fd)
  		return EXIT_FAILURE;
  	/* If they gave us no args, assume they want the last backgrounded task */
  	if (!argv[1]) {
  		for (pi = G.job_list; pi; pi = pi->next) {
-Line 4571 
 static int builtin_fg_bg(char **argv)
+Line 7616 
 static int builtin_fg_bg(char **argv)
  	bb_error_msg("%s: %d: no such job", argv[0], jobnum);
  	return EXIT_FAILURE;
   found:
- 	// TODO: bash prints a string representation
+ 	/* TODO: bash prints a string representation
- 	// of job being foregrounded (like "sleep 1 | cat")
+ 	 * of job being foregrounded (like "sleep 1 | cat") */
- 	if (*argv[0] == 'f') {
+ 	if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
  		/* Put the job into the foreground.  */
- 		tcsetpgrp(G.interactive_fd, pi->pgrp);
+ 		tcsetpgrp(G_interactive_fd, pi->pgrp);
  	}
  	/* Restart the processes in the job */
-Line 4591 
 static int builtin_fg_bg(char **argv)
+Line 7636 
 static int builtin_fg_bg(char **argv)
  		if (errno == ESRCH) {
  			delete_finished_bg_job(pi);
  			return EXIT_SUCCESS;
- 		} else {
- 			bb_perror_msg("kill (SIGCONT)");
  		}
+ 		bb_perror_msg("kill (SIGCONT)");
  	}
- 	if (*argv[0] == 'f') {
+ 	if (argv[0][0] == 'f') {
  		remove_bg_job(pi);
  		return checkjobs_and_fg_shell(pi);
  	}
-Line 4605 
 static int builtin_fg_bg(char **argv)
+Line 7649 
 static int builtin_fg_bg(char **argv)
  #endif
  #if ENABLE_HUSH_HELP
- static int builtin_help(char **argv UNUSED_PARAM)
+ static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
  {
  	const struct built_in_command *x;
- 	printf("\nBuilt-in commands:\n");
+ 	printf(
- 	printf("-------------------\n");
+ 		"Built-in commands:\n"
- 	for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
+ 		"------------------\n");
- 		printf("%s\t%s\n", x->cmd, x->descr);
+ 	for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
+ 		if (x->descr)
+ 			printf("%s\t%s\n", x->cmd, x->descr);
  	}
- 	printf("\n\n");
+ 	bb_putchar('\n');
  	return EXIT_SUCCESS;
  }
  #endif
  #if ENABLE_HUSH_JOB
- static int builtin_jobs(char **argv UNUSED_PARAM)
+ static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
  {
  	struct pipe *job;
  	const char *status_string;
-Line 4637 
 static int builtin_jobs(char **argv UNUS
+Line 7683 
 static int builtin_jobs(char **argv UNUS
  }
  #endif
- static int builtin_pwd(char **argv UNUSED_PARAM)
+ #if HUSH_DEBUG
+ static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
+ {
+ 	void *p;
+ 	unsigned long l;
+ # ifdef M_TRIM_THRESHOLD
+ 	/* Optional. Reduces probability of false positives */
+ 	malloc_trim(0);
+ # endif
+ 	/* Crude attempt to find where "free memory" starts,
+ 	 * sans fragmentation. */
+ 	p = malloc(240);
+ 	l = (unsigned long)p;
+ 	free(p);
+ 	p = malloc(3400);
+ 	if (l < (unsigned long)p) l = (unsigned long)p;
+ 	free(p);
+ 	if (!G.memleak_value)
+ 		G.memleak_value = l;
+ 	l -= G.memleak_value;
+ 	if ((long)l < 0)
+ 		l = 0;
+ 	l /= 1024;
+ 	if (l > 127)
+ 		l = 127;
+ 	/* Exitcode is "how many kilobytes we leaked since 1st call" */
+ 	return l;
+ }
+ #endif
+ static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
  {
- 	puts(set_cwd());
+ 	puts(get_cwd(0));
  	return EXIT_SUCCESS;
  }
- static int builtin_read(char **argv)
+ static int FAST_FUNC builtin_read(char **argv)
  {
- 	char *string;
+ 	const char *r;
- 	const char *name = argv[1] ? argv[1] : "REPLY";
+ 	char *opt_n = NULL;
+ 	char *opt_p = NULL;
+ 	char *opt_t = NULL;
+ 	char *opt_u = NULL;
+ 	int read_flags;
+ 	/* "!": do not abort on errors.
+ 	 * Option string must start with "sr" to match BUILTIN_READ_xxx
+ 	 */
+ 	read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
+ 	if (read_flags == (uint32_t)-1)
+ 		return EXIT_FAILURE;
+ 	argv += optind;
- 	string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
+ 	r = shell_builtin_read(set_local_var_from_halves,
- 	return set_local_var(string, 0);
+ 		argv,
+ 		get_local_var_value("IFS"), /* can be NULL */
+ 		read_flags,
+ 		opt_n,
+ 		opt_p,
+ 		opt_t,
+ 		opt_u
+ 	);
+ 	if ((uintptr_t)r > 1) {
+ 		bb_error_msg("%s", r);
+ 		r = (char*)(uintptr_t)1;
+ 	}
+ 	return (uintptr_t)r;
  }
- /* built-in 'set' handler
+ /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
+  * built-in 'set' handler
   * SUSv3 says:
-  * set [-abCefmnuvx] [-h] [-o option] [argument...]
+  * set [-abCefhmnuvx] [-o option] [argument...]
-  * set [+abCefmnuvx] [+h] [+o option] [argument...]
+  * set [+abCefhmnuvx] [+o option] [argument...]
   * set -- [argument...]
   * set -o
   * set +o
-Line 4670 
 static int builtin_read(char **argv)
+Line 7777 
 static int builtin_read(char **argv)
   * Set the positional parameters to the expansion of x, even if x expands
   * with a leading '-' or '+': set -- $x
   *
-  * So far, we only support "set -- [argument...]" by ignoring all options
+  * So far, we only support "set -- [argument...]" and some of the short names.
-  * (also, "-o option" will be mishandled by taking "option" as parameter #1).
   */
- static int builtin_set(char **argv)
+ static int FAST_FUNC builtin_set(char **argv)
  {
- 	struct variable *e;
+ 	int n;
- 	char **pp;
+ 	char **pp, **g_argv;
  	char *arg = *++argv;
  	if (arg == NULL) {
+ 		struct variable *e;
  		for (e = G.top_var; e; e = e->next)
  			puts(e->varstr);
- 	} else {
+ 		return EXIT_SUCCESS;
- 		/* NB: G.global_argv[0] ($0) is never freed/changed */
+ 	}
- 		if (G.global_args_malloced) {
+ 	do {
- 			pp = G.global_argv;
+ 		if (!strcmp(arg, "--")) {
- 			while (*++pp)
+ 			++argv;
- 				free(*pp);
+ 			goto set_argv;
- 			G.global_argv[1] = NULL;
- 		} else {
- 			G.global_args_malloced = 1;
- 			pp = xzalloc(sizeof(pp[0]) * 2);
- 			pp[0] = G.global_argv[0]; /* retain $0 */
- 			G.global_argv = pp;
  		}
- 		do  {
+ 		if (arg[0] != '+' && arg[0] != '-')
- 			if (arg[0] == '+')
+ 			break;
- 				continue;
+ 		for (n = 1; arg[n]; ++n)
- 			if (arg[0] != '-')
+ 			if (set_mode(arg[0], arg[n]))
- 				break;
+ 				goto error;
- 			if (arg[1] == '-' && arg[2] == '\0') {
+ 	} while ((arg = *++argv) != NULL);
- 				argv++;
+ 	/* Now argv[0] is 1st argument */
- 				break;
- 			}
+ 	if (arg == NULL)
- 		} while ((arg = *++argv) != NULL);
+ 		return EXIT_SUCCESS;
- 		/* Now argv[0] is 1st argument */
+  set_argv:
- 		/* This realloc's G.global_argv */
+ 	/* NB: G.global_argv[0] ($0) is never freed/changed */
- 		G.global_argv = pp = add_strings_to_strings(G.global_argv, argv, /*dup:*/ 1);
+ 	g_argv = G.global_argv;
- 		G.global_argc = 1;
+ 	if (G.global_args_malloced) {
+ 		pp = g_argv;
  		while (*++pp)
- 			G.global_argc++;
+ 			free(*pp);
- 	}
+ 		g_argv[1] = NULL;
+ 	} else {
+ 		G.global_args_malloced = 1;
+ 		pp = xzalloc(sizeof(pp[0]) * 2);
+ 		pp[0] = g_argv[0]; /* retain $0 */
+ 		g_argv = pp;
+ 	}
+ 	/* This realloc's G.global_argv */
+ 	G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
+ 	n = 1;
+ 	while (*++pp)
+ 		n++;
+ 	G.global_argc = n;
  	return EXIT_SUCCESS;
+ 	/* Nothing known, so abort */
+  error:
+ 	bb_error_msg("set: %s: invalid option", arg);
+ 	return EXIT_FAILURE;
  }
- static int builtin_shift(char **argv)
+ static int FAST_FUNC builtin_shift(char **argv)
  {
  	int n = 1;
  	if (argv[1]) {
-Line 4738 
 static int builtin_shift(char **argv)
+Line 7858 
 static int builtin_shift(char **argv)
  	return EXIT_FAILURE;
  }
- static int builtin_source(char **argv)
+ static int FAST_FUNC builtin_source(char **argv)
  {
+ 	char *arg_path;
  	FILE *input;
- 	int status;
+ 	save_arg_t sv;
+ #if ENABLE_HUSH_FUNCTIONS
+ 	smallint sv_flg;
+ #endif
- 	if (argv[1] == NULL)
+ 	if (*++argv == NULL)
  		return EXIT_FAILURE;
- 	/* XXX search through $PATH is missing */
+ 	if (strchr(*argv, '/') == NULL && (arg_path = find_in_path(*argv)) != NULL) {
- 	input = fopen_for_read(argv[1]);
+ 		input = fopen_for_read(arg_path);
+ 		free(arg_path);
+ 	} else
+ 		input = fopen_or_warn(*argv, "r");
  	if (!input) {
- 		bb_error_msg("can't open '%s'", argv[1]);
+ 		/* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
  		return EXIT_FAILURE;
  	}
  	close_on_exec_on(fileno(input));
- 	/* Now run the file */
+ #if ENABLE_HUSH_FUNCTIONS
- 	/* XXX argv and argc are broken; need to save old G.global_argv
+ 	sv_flg = G.flag_return_in_progress;
- 	 * (pointer only is OK!) on this stack frame,
+ 	/* "we are inside sourced file, ok to use return" */
- 	 * set G.global_argv=argv+1, recurse, and restore. */
+ 	G.flag_return_in_progress = -1;
- 	status = parse_and_run_file(input);
+ #endif
+ 	save_and_replace_G_args(&sv, argv);
+ 	parse_and_run_file(input);
  	fclose(input);
- 	return status;
+ 	restore_G_args(&sv, argv);
+ #if ENABLE_HUSH_FUNCTIONS
+ 	G.flag_return_in_progress = sv_flg;
+ #endif
+ 	return G.last_exitcode;
  }
- static int builtin_umask(char **argv)
+ static int FAST_FUNC builtin_umask(char **argv)
  {
- 	mode_t new_umask;
+ 	int rc;
- 	const char *arg = argv[1];
+ 	mode_t mask;
- 	char *end;
- 	if (arg) {
+ 	mask = umask(0);
- 		new_umask = strtoul(arg, &end, 8);
+ 	if (argv[1]) {
- 		if (*end != '\0' || end == arg) {
+ 		mode_t old_mask = mask;
- 			return EXIT_FAILURE;
+ 		mask ^= 0777;
+ 		rc = bb_parse_mode(argv[1], &mask);
+ 		mask ^= 0777;
+ 		if (rc == 0) {
+ 			mask = old_mask;
+ 			/* bash messages:
+ 			 * bash: umask: 'q': invalid symbolic mode operator
+ 			 * bash: umask: 999: octal number out of range
+ 			 */
+ 			bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
  		}
  	} else {
- 		new_umask = umask(0);
+ 		rc = 1;
- 		printf("%.3o\n", (unsigned) new_umask);
+ 		/* Mimic bash */
+ 		printf("%04o\n", (unsigned) mask);
+ 		/* fall through and restore mask which we set to 0 */
  	}
- 	umask(new_umask);
+ 	umask(mask);
- 	return EXIT_SUCCESS;
+ 	return !rc; /* rc != 0 - success */
  }
- static int builtin_unset(char **argv)
+ /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
+ static int FAST_FUNC builtin_unset(char **argv)
  {
- 	/* bash always returns true */
+ 	int ret;
- 	unset_local_var(argv[1]);
+ 	unsigned opts;
- 	return EXIT_SUCCESS;
+ 	/* "!": do not abort on errors */
+ 	/* "+": stop at 1st non-option */
+ 	opts = getopt32(argv, "!+vf");
+ 	if (opts == (unsigned)-1)
+ 		return EXIT_FAILURE;
+ 	if (opts == 3) {
+ 		bb_error_msg("unset: -v and -f are exclusive");
+ 		return EXIT_FAILURE;
+ 	}
+ 	argv += optind;
+ 	ret = EXIT_SUCCESS;
+ 	while (*argv) {
+ 		if (!(opts & 2)) { /* not -f */
+ 			if (unset_local_var(*argv)) {
+ 				/* unset <nonexistent_var> doesn't fail.
+ 				 * Error is when one tries to unset RO var.
+ 				 * Message was printed by unset_local_var. */
+ 				ret = EXIT_FAILURE;
+ 			}
+ 		}
+ #if ENABLE_HUSH_FUNCTIONS
+ 		else {
+ 			unset_func(*argv);
+ 		}
+ #endif
+ 		argv++;
+ 	}
+ 	return ret;
+ }
+ /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
+ static int FAST_FUNC builtin_wait(char **argv)
+ {
+ 	int ret = EXIT_SUCCESS;
+ 	int status, sig;
+ 	if (*++argv == NULL) {
+ 		/* Don't care about wait results */
+ 		/* Note 1: must wait until there are no more children */
+ 		/* Note 2: must be interruptible */
+ 		/* Examples:
+ 		 * $ sleep 3 & sleep 6 & wait
+ 		 * [1] 30934 sleep 3
+ 		 * [2] 30935 sleep 6
+ 		 * [1] Done                   sleep 3
+ 		 * [2] Done                   sleep 6
+ 		 * $ sleep 3 & sleep 6 & wait
+ 		 * [1] 30936 sleep 3
+ 		 * [2] 30937 sleep 6
+ 		 * [1] Done                   sleep 3
+ 		 * ^C <-- after ~4 sec from keyboard
+ 		 * $
+ 		 */
+ 		sigaddset(&G.blocked_set, SIGCHLD);
+ 		sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+ 		while (1) {
+ 			checkjobs(NULL);
+ 			if (errno == ECHILD)
+ 				break;
+ 			/* Wait for SIGCHLD or any other signal of interest */
+ 			/* sigtimedwait with infinite timeout: */
+ 			sig = sigwaitinfo(&G.blocked_set, NULL);
+ 			if (sig > 0) {
+ 				sig = check_and_run_traps(sig);
+ 				if (sig && sig != SIGCHLD) { /* see note 2 */
+ 					ret = 128 + sig;
+ 					break;
+ 				}
+ 			}
+ 		}
+ 		sigdelset(&G.blocked_set, SIGCHLD);
+ 		sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+ 		return ret;
+ 	}
+ 	/* This is probably buggy wrt interruptible-ness */
+ 	while (*argv) {
+ 		pid_t pid = bb_strtou(*argv, NULL, 10);
+ 		if (errno) {
+ 			/* mimic bash message */
+ 			bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
+ 			return EXIT_FAILURE;
+ 		}
+ 		if (waitpid(pid, &status, 0) == pid) {
+ 			if (WIFSIGNALED(status))
+ 				ret = 128 + WTERMSIG(status);
+ 			else if (WIFEXITED(status))
+ 				ret = WEXITSTATUS(status);
+ 			else /* wtf? */
+ 				ret = EXIT_FAILURE;
+ 		} else {
+ 			bb_perror_msg("wait %s", *argv);
+ 			ret = 127;
+ 		}
+ 		argv++;
+ 	}
+ 	return ret;
  }
+ #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
+ static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
+ {
+ 	if (argv[1]) {
+ 		def = bb_strtou(argv[1], NULL, 10);
+ 		if (errno || def < def_min || argv[2]) {
+ 			bb_error_msg("%s: bad arguments", argv[0]);
+ 			def = UINT_MAX;
+ 		}
+ 	}
+ 	return def;
+ }
+ #endif
  #if ENABLE_HUSH_LOOPS
- static int builtin_break(char **argv)
+ static int FAST_FUNC builtin_break(char **argv)
  {
+ 	unsigned depth;
  	if (G.depth_of_loop == 0) {
  		bb_error_msg("%s: only meaningful in a loop", argv[0]);
  		return EXIT_SUCCESS; /* bash compat */
  	}
  	G.flag_break_continue++; /* BC_BREAK = 1 */
- 	G.depth_break_continue = 1;
- 	if (argv[1]) {
+ 	G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
- 		G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
+ 	if (depth == UINT_MAX)
- 		if (errno || !G.depth_break_continue || argv[2]) {
+ 		G.flag_break_continue = BC_BREAK;
- 			bb_error_msg("%s: bad arguments", argv[0]);
+ 	if (G.depth_of_loop < depth)
- 			G.flag_break_continue = BC_BREAK;
- 			G.depth_break_continue = UINT_MAX;
- 		}
- 	}
- 	if (G.depth_of_loop < G.depth_break_continue)
  		G.depth_break_continue = G.depth_of_loop;
  	return EXIT_SUCCESS;
  }
- static int builtin_continue(char **argv)
+ static int FAST_FUNC builtin_continue(char **argv)
  {
  	G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
  	return builtin_break(argv);
  }
  #endif
+ #if ENABLE_HUSH_FUNCTIONS
+ static int FAST_FUNC builtin_return(char **argv)
+ {
+ 	int rc;
+ 	if (G.flag_return_in_progress != -1) {
+ 		bb_error_msg("%s: not in a function or sourced script", argv[0]);
+ 		return EXIT_FAILURE; /* bash compat */
+ 	}
+ 	G.flag_return_in_progress = 1;
+ 	/* bash:
+ 	 * out of range: wraps around at 256, does not error out
+ 	 * non-numeric param:
+ 	 * f() { false; return qwe; }; f; echo $?
+ 	 * bash: return: qwe: numeric argument required  <== we do this
+ 	 * 255  <== we also do this
+ 	 */
+ 	rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
+ 	return rc;
+ }
+ #endif

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