busybox/findutils/xargs.c

/* vi: set sw=4 ts=4: */
/*
 * Mini xargs implementation for busybox
 * Options are supported: "-prtx -n max_arg -s max_chars -e[ouf_str]"
 *
 * (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>
 *
 * Special thanks
 * - Mark Whitley and Glenn McGrath for stimulus to rewrite :)
 * - Mike Rendell <michael@cs.mun.ca>
 * and David MacKenzie <djm@gnu.ai.mit.edu>.
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 *
 * xargs is described in the Single Unix Specification v3 at
 * http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html
 *
 */

#include "busybox.h"

/* COMPAT:  SYSV version defaults size (and has a max value of) to 470.
   We try to make it as large as possible. */
#if !defined(ARG_MAX) && defined(_SC_ARG_MAX)
#define ARG_MAX sysconf (_SC_ARG_MAX)
#endif
#ifndef ARG_MAX
#define ARG_MAX 470
#endif


#ifdef TEST
# ifndef CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION
#  define CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION
# endif
# ifndef CONFIG_FEATURE_XARGS_SUPPORT_QUOTES
#  define CONFIG_FEATURE_XARGS_SUPPORT_QUOTES
# endif
# ifndef CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT
#  define CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT
# endif
# ifndef CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM
#  define CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM
# endif
#endif

/*
   This function has special algorithm.
   Don't use fork and include to main!
*/
static int xargs_exec(char *const *args)
{
	pid_t p;
	volatile int exec_errno = 0;    /* shared vfork stack */
	int status;

	p = vfork();
	if (p < 0)
		bb_perror_msg_and_die("vfork");

	if (p == 0) {
		/* vfork -- child */
		execvp(args[0], args);
		exec_errno = errno;     /* set error to shared stack */
		_exit(1);
	}

	/* vfork -- parent */
	while (wait(&status) == (pid_t) -1)
		if (errno != EINTR)
			break;
	if (exec_errno) {
		errno = exec_errno;
		bb_perror_msg("%s", args[0]);
		return exec_errno == ENOENT ? 127 : 126;
	}
	if (WEXITSTATUS(status) == 255) {
		bb_error_msg("%s: exited with status 255; aborting", args[0]);
		return 124;
	}
	if (WIFSTOPPED(status)) {
		bb_error_msg("%s: stopped by signal %d",
			args[0], WSTOPSIG(status));
		return 125;
	}
	if (WIFSIGNALED(status)) {
		bb_error_msg("%s: terminated by signal %d",
			args[0], WTERMSIG(status));
		return 125;
	}
	if (WEXITSTATUS(status))
		return 123;
	return 0;
}


typedef struct xlist_s {
	char *data;
	size_t lenght;
	struct xlist_s *link;
} xlist_t;

static int eof_stdin_detected;

#define ISBLANK(c) ((c) == ' ' || (c) == '\t')
#define ISSPACE(c) (ISBLANK(c) || (c) == '\n' || (c) == '\r' \
		    || (c) == '\f' || (c) == '\v')

#ifdef CONFIG_FEATURE_XARGS_SUPPORT_QUOTES
static xlist_t *process_stdin(xlist_t * list_arg,
	const char *eof_str, size_t mc, char *buf)
{
#define NORM      0
#define QUOTE     1
#define BACKSLASH 2
#define SPACE     4

	char *s = NULL;         /* start word */
	char *p = NULL;         /* pointer to end word */
	char q = 0;             /* quote char */
	char state = NORM;
	char eof_str_detected = 0;
	size_t line_l = 0;      /* size loaded args line */
	int c;                  /* current char */
	xlist_t *cur;
	xlist_t *prev;

	for (prev = cur = list_arg; cur; cur = cur->link) {
		line_l += cur->lenght;  /* previous allocated */
		if (prev != cur)
			prev = prev->link;
	}

	while (!eof_stdin_detected) {
		c = getchar();
		if (c == EOF) {
			eof_stdin_detected++;
			if (s)
				goto unexpected_eof;
			break;
		}
		if (eof_str_detected)
			continue;
		if (state == BACKSLASH) {
			state = NORM;
			goto set;
		} else if (state == QUOTE) {
			if (c == q) {
				q = 0;
				state = NORM;
			} else {
				goto set;
			}
		} else { /* if(state == NORM) */

			if (ISSPACE(c)) {
				if (s) {
unexpected_eof:
					state = SPACE;
					c = 0;
					goto set;
				}
			} else {
				if (s == NULL)
					s = p = buf;
				if (c == '\\') {
					state = BACKSLASH;
				} else if (c == '\'' || c == '"') {
					q = c;
					state = QUOTE;
				} else {
set:
					if ((size_t)(p - buf) >= mc)
						bb_error_msg_and_die("argument line too long");
					*p++ = c;
				}
			}
		}
		if (state == SPACE) {   /* word's delimiter or EOF detected */
			if (q) {
				bb_error_msg_and_die("unmatched %s quote",
					q == '\'' ? "single" : "double");
			}
			/* word loaded */
			if (eof_str) {
				eof_str_detected = strcmp(s, eof_str) == 0;
			}
			if (!eof_str_detected) {
				size_t lenght = (p - buf);

				cur = xmalloc(sizeof(xlist_t) + lenght);
				cur->data = memcpy(cur + 1, s, lenght);
				cur->lenght = lenght;
				cur->link = NULL;
				if (prev == NULL) {
					list_arg = cur;
				} else {
					prev->link = cur;
				}
				prev = cur;
				line_l += lenght;
				if (line_l > mc) {
					/* stop memory usage :-) */
					break;
				}
			}
			s = NULL;
			state = NORM;
		}
	}
	return list_arg;
}
#else
/* The variant does not support single quotes, double quotes or backslash */
static xlist_t *process_stdin(xlist_t * list_arg,
	const char *eof_str, size_t mc, char *buf)
{

	int c;                  /* current char */
	int eof_str_detected = 0;
	char *s = NULL;         /* start word */
	char *p = NULL;         /* pointer to end word */
	size_t line_l = 0;      /* size loaded args line */
	xlist_t *cur;
	xlist_t *prev;

	for (prev = cur = list_arg; cur; cur = cur->link) {
		line_l += cur->lenght;  /* previous allocated */
		if (prev != cur)
			prev = prev->link;
	}

	while (!eof_stdin_detected) {
		c = getchar();
		if (c == EOF) {
			eof_stdin_detected++;
		}
		if (eof_str_detected)
			continue;
		if (c == EOF || ISSPACE(c)) {
			if (s == NULL)
				continue;
			c = EOF;
		}
		if (s == NULL)
			s = p = buf;
		if ((p - buf) >= mc)
			bb_error_msg_and_die("argument line too long");
		*p++ = c == EOF ? 0 : c;
		if (c == EOF) { /* word's delimiter or EOF detected */
			/* word loaded */
			if (eof_str) {
				eof_str_detected = strcmp(s, eof_str) == 0;
			}
			if (!eof_str_detected) {
				size_t lenght = (p - buf);

				cur = xmalloc(sizeof(xlist_t) + lenght);
				cur->data = memcpy(cur + 1, s, lenght);
				cur->lenght = lenght;
				cur->link = NULL;
				if (prev == NULL) {
					list_arg = cur;
				} else {
					prev->link = cur;
				}
				prev = cur;
				line_l += lenght;
				if (line_l > mc) {
					/* stop memory usage :-) */
					break;
				}
				s = NULL;
			}
		}
	}
	return list_arg;
}
#endif /* CONFIG_FEATURE_XARGS_SUPPORT_QUOTES */


#ifdef CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION
/* Prompt the user for a response, and
   if the user responds affirmatively, return true;
   otherwise, return false. Used "/dev/tty", not stdin. */
static int xargs_ask_confirmation(void)
{
	static FILE *tty_stream;
	int c, savec;

	if (!tty_stream) {
		tty_stream = xfopen(CURRENT_TTY, "r");
		/* pranoidal security by vodz */
		fcntl(fileno(tty_stream), F_SETFD, FD_CLOEXEC);
	}
	fputs(" ?...", stderr);
	fflush(stderr);
	c = savec = getc(tty_stream);
	while (c != EOF && c != '\n')
		c = getc(tty_stream);
	if (savec == 'y' || savec == 'Y')
		return 1;
	return 0;
}
#else
# define xargs_ask_confirmation() 1
#endif /* CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION */

#ifdef CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM
static xlist_t *process0_stdin(xlist_t * list_arg, const char *eof_str ATTRIBUTE_UNUSED,
							   size_t mc, char *buf)
{
	int c;                  /* current char */
	char *s = NULL;         /* start word */
	char *p = NULL;         /* pointer to end word */
	size_t line_l = 0;      /* size loaded args line */
	xlist_t *cur;
	xlist_t *prev;

	for (prev = cur = list_arg; cur; cur = cur->link) {
		line_l += cur->lenght;  /* previous allocated */
		if (prev != cur)
			prev = prev->link;
	}

	while (!eof_stdin_detected) {
		c = getchar();
		if (c == EOF) {
			eof_stdin_detected++;
			if (s == NULL)
				break;
			c = 0;
		}
		if (s == NULL)
			s = p = buf;
		if ((size_t)(p - buf) >= mc)
			bb_error_msg_and_die("argument line too long");
		*p++ = c;
		if (c == 0) {   /* word's delimiter or EOF detected */
			/* word loaded */
			size_t lenght = (p - buf);

			cur = xmalloc(sizeof(xlist_t) + lenght);
			cur->data = memcpy(cur + 1, s, lenght);
			cur->lenght = lenght;
			cur->link = NULL;
			if (prev == NULL) {
				list_arg = cur;
			} else {
				prev->link = cur;
			}
			prev = cur;
			line_l += lenght;
			if (line_l > mc) {
				/* stop memory usage :-) */
				break;
			}
			s = NULL;
		}
	}
	return list_arg;
}
#endif /* CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM */

/* Correct regardless of combination of CONFIG_xxx */
enum {
	OPTBIT_VERBOSE = 0,
	OPTBIT_NO_EMPTY,
	OPTBIT_UPTO_NUMBER,
	OPTBIT_UPTO_SIZE,
	OPTBIT_EOF_STRING,
	USE_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
	USE_FEATURE_XARGS_SUPPORT_TERMOPT(     OPTBIT_TERMINATE  ,)
	USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   OPTBIT_ZEROTERM   ,)

	OPT_VERBOSE     = 1<<OPTBIT_VERBOSE    ,
	OPT_NO_EMPTY    = 1<<OPTBIT_NO_EMPTY   ,
	OPT_UPTO_NUMBER = 1<<OPTBIT_UPTO_NUMBER,
	OPT_UPTO_SIZE   = 1<<OPTBIT_UPTO_SIZE  ,
	OPT_EOF_STRING  = 1<<OPTBIT_EOF_STRING ,
	OPT_INTERACTIVE = USE_FEATURE_XARGS_SUPPORT_CONFIRMATION((1<<OPTBIT_INTERACTIVE)) + 0,
	OPT_TERMINATE   = USE_FEATURE_XARGS_SUPPORT_TERMOPT(     (1<<OPTBIT_TERMINATE  )) + 0,
	OPT_ZEROTERM    = USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   (1<<OPTBIT_ZEROTERM   )) + 0,
};
#define OPTION_STR "+trn:s:e::" \
	USE_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
	USE_FEATURE_XARGS_SUPPORT_TERMOPT(     "x") \
	USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   "0")

int xargs_main(int argc, char **argv)
{
	char **args;
	int i, n;
	xlist_t *list = NULL;
	xlist_t *cur;
	int child_error = 0;
	char *max_args, *max_chars;
	int n_max_arg;
	size_t n_chars = 0;
	long orig_arg_max;
	const char *eof_str = "_";
	unsigned opt;
	size_t n_max_chars;
#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
	xlist_t* (*read_args)(xlist_t*, const char*, size_t, char*) = process_stdin;
#else
#define read_args process_stdin
#endif

	opt = getopt32(argc, argv, OPTION_STR, &max_args, &max_chars, &eof_str);

	if (opt & OPT_ZEROTERM)
		USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);

	argc -= optind;
	argv += optind;
	if (!argc) {
		/* default behavior is to echo all the filenames */
		*argv = "echo";
		argc++;
	}

	orig_arg_max = ARG_MAX;
	if (orig_arg_max == -1)
		orig_arg_max = LONG_MAX;
	orig_arg_max -= 2048;   /* POSIX.2 requires subtracting 2048 */

	if (opt & OPT_UPTO_SIZE) {
		n_max_chars = xatoul_range(max_chars, 1, orig_arg_max);
		for (i = 0; i < argc; i++) {
			n_chars += strlen(*argv) + 1;
		}
		if (n_max_chars < n_chars) {
			bb_error_msg_and_die("cannot fit single argument within argument list size limit");
		}
		n_max_chars -= n_chars;
	} else {
		/* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which
		   have it at 1 meg).  Things will work fine with a large ARG_MAX but it
		   will probably hurt the system more than it needs to; an array of this
		   size is allocated.  */
		if (orig_arg_max > 20 * 1024)
			orig_arg_max = 20 * 1024;
		n_max_chars = orig_arg_max;
	}
	max_chars = xmalloc(n_max_chars);

	if (opt & OPT_UPTO_NUMBER) {
		n_max_arg = xatoul_range(max_args, 1, INT_MAX);
	} else {
		n_max_arg = n_max_chars;
	}

	while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL ||
		!(opt & OPT_NO_EMPTY))
	{
		opt |= OPT_NO_EMPTY;
		n = 0;
		n_chars = 0;
#ifdef CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT
		for (cur = list; cur;) {
			n_chars += cur->lenght;
			n++;
			cur = cur->link;
			if (n_chars > n_max_chars || (n == n_max_arg && cur)) {
				if (opt & OPT_TERMINATE)
					bb_error_msg_and_die("argument list too long");
				break;
			}
		}
#else
		for (cur = list; cur; cur = cur->link) {
			n_chars += cur->lenght;
			n++;
			if (n_chars > n_max_chars || n == n_max_arg) {
				break;
			}
		}
#endif /* CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT */

		/* allocate pointers for execvp:
		   argc*arg, n*arg from stdin, NULL */
		args = xzalloc((n + argc + 1) * sizeof(char *));

		/* store the command to be executed
		   (taken from the command line) */
		for (i = 0; i < argc; i++)
			args[i] = argv[i];
		/* (taken from stdin) */
		for (cur = list; n; cur = cur->link) {
			args[i++] = cur->data;
			n--;
		}

		if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) {
			for (i = 0; args[i]; i++) {
				if (i)
					fputc(' ', stderr);
				fputs(args[i], stderr);
			}
			if (!(opt & OPT_INTERACTIVE))
				fputc('\n', stderr);
		}
		if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) {
			child_error = xargs_exec(args);
		}

		/* clean up */
		for (i = argc; args[i]; i++) {
			cur = list;
			list = list->link;
			free(cur);
		}
		free(args);
		if (child_error > 0 && child_error != 123) {
			break;
		}
	}
	if (ENABLE_FEATURE_CLEAN_UP) free(max_chars);
	return child_error;
}


#ifdef TEST

const char *applet_name = "debug stuff usage";

void bb_show_usage(void)
{
	fprintf(stderr, "Usage: %s [-p] [-r] [-t] -[x] [-n max_arg] [-s max_chars]\n",
		applet_name);
	exit(1);
}

int main(int argc, char **argv)
{
	return xargs_main(argc, argv);
}
#endif /* TEST */
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Mini xargs implementation for busybox
4	* Options are supported: "-prtx -n max_arg -s max_chars -e[ouf_str]"
5	*
6	* (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>
7	*
8	* Special thanks
9	* - Mark Whitley and Glenn McGrath for stimulus to rewrite :)
10	* - Mike Rendell <michael@cs.mun.ca>
11	* and David MacKenzie <djm@gnu.ai.mit.edu>.
12	*
13	* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
14	*
15	* xargs is described in the Single Unix Specification v3 at
16	* http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html
17	*
18	*/
19
20	#include "busybox.h"
21
22	/* COMPAT: SYSV version defaults size (and has a max value of) to 470.
23	We try to make it as large as possible. */
24	#if !defined(ARG_MAX) && defined(_SC_ARG_MAX)
25	#define ARG_MAX sysconf (_SC_ARG_MAX)
26	#endif
27	#ifndef ARG_MAX
28	#define ARG_MAX 470
29	#endif
30
31
32	#ifdef TEST
33	# ifndef CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION
34	# define CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION
35	# endif
36	# ifndef CONFIG_FEATURE_XARGS_SUPPORT_QUOTES
37	# define CONFIG_FEATURE_XARGS_SUPPORT_QUOTES
38	# endif
39	# ifndef CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT
40	# define CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT
41	# endif
42	# ifndef CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM
43	# define CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM
44	# endif
45	#endif
46
47	/*
48	This function has special algorithm.
49	Don't use fork and include to main!
50	*/
51	static int xargs_exec(char const args)
52	{
53	pid_t p;
54	volatile int exec_errno = 0; /* shared vfork stack */
55	int status;
56
57	p = vfork();
58	if (p < 0)
59	bb_perror_msg_and_die("vfork");
60
61	if (p == 0) {
62	/* vfork -- child */
63	execvp(args[0], args);
64	exec_errno = errno; /* set error to shared stack */
65	_exit(1);
66	}
67
68	/* vfork -- parent */
69	while (wait(&status) == (pid_t) -1)
70	if (errno != EINTR)
71	break;
72	if (exec_errno) {
73	errno = exec_errno;
74	bb_perror_msg("%s", args[0]);
75	return exec_errno == ENOENT ? 127 : 126;
76	}
77	if (WEXITSTATUS(status) == 255) {
78	bb_error_msg("%s: exited with status 255; aborting", args[0]);
79	return 124;
80	}
81	if (WIFSTOPPED(status)) {
82	bb_error_msg("%s: stopped by signal %d",
83	args[0], WSTOPSIG(status));
84	return 125;
85	}
86	if (WIFSIGNALED(status)) {
87	bb_error_msg("%s: terminated by signal %d",
88	args[0], WTERMSIG(status));
89	return 125;
90	}
91	if (WEXITSTATUS(status))
92	return 123;
93	return 0;
94	}
95
96
97	typedef struct xlist_s {
98	char *data;
99	size_t lenght;
100	struct xlist_s *link;
101	} xlist_t;
102
103	static int eof_stdin_detected;
104
105	#define ISBLANK(c) ((c) == ' ' \|\| (c) == '\t')
106	#define ISSPACE(c) (ISBLANK(c) \|\| (c) == '\n' \|\| (c) == '\r' \
107	\|\| (c) == '\f' \|\| (c) == '\v')
108
109	#ifdef CONFIG_FEATURE_XARGS_SUPPORT_QUOTES
110	static xlist_t process_stdin(xlist_t list_arg,
111	const char eof_str, size_t mc, char buf)
112	{
113	#define NORM 0
114	#define QUOTE 1
115	#define BACKSLASH 2
116	#define SPACE 4
117
118	char s = NULL; / start word */
119	char p = NULL; / pointer to end word */
120	char q = 0; /* quote char */
121	char state = NORM;
122	char eof_str_detected = 0;
123	size_t line_l = 0; /* size loaded args line */
124	int c; /* current char */
125	xlist_t *cur;
126	xlist_t *prev;
127
128	for (prev = cur = list_arg; cur; cur = cur->link) {
129	line_l += cur->lenght; /* previous allocated */
130	if (prev != cur)
131	prev = prev->link;
132	}
133
134	while (!eof_stdin_detected) {
135	c = getchar();
136	if (c == EOF) {
137	eof_stdin_detected++;
138	if (s)
139	goto unexpected_eof;
140	break;
141	}
142	if (eof_str_detected)
143	continue;
144	if (state == BACKSLASH) {
145	state = NORM;
146	goto set;
147	} else if (state == QUOTE) {
148	if (c == q) {
149	q = 0;
150	state = NORM;
151	} else {
152	goto set;
153	}
154	} else { /* if(state == NORM) */
155
156	if (ISSPACE(c)) {
157	if (s) {
158	unexpected_eof:
159	state = SPACE;
160	c = 0;
161	goto set;
162	}
163	} else {
164	if (s == NULL)
165	s = p = buf;
166	if (c == '\\') {
167	state = BACKSLASH;
168	} else if (c == '\'' \|\| c == '"') {
169	q = c;
170	state = QUOTE;
171	} else {
172	set:
173	if ((size_t)(p - buf) >= mc)
174	bb_error_msg_and_die("argument line too long");
175	*p++ = c;
176	}
177	}
178	}
179	if (state == SPACE) { /* word's delimiter or EOF detected */
180	if (q) {
181	bb_error_msg_and_die("unmatched %s quote",
182	q == '\'' ? "single" : "double");
183	}
184	/* word loaded */
185	if (eof_str) {
186	eof_str_detected = strcmp(s, eof_str) == 0;
187	}
188	if (!eof_str_detected) {
189	size_t lenght = (p - buf);
190
191	cur = xmalloc(sizeof(xlist_t) + lenght);
192	cur->data = memcpy(cur + 1, s, lenght);
193	cur->lenght = lenght;
194	cur->link = NULL;
195	if (prev == NULL) {
196	list_arg = cur;
197	} else {
198	prev->link = cur;
199	}
200	prev = cur;
201	line_l += lenght;
202	if (line_l > mc) {
203	/* stop memory usage :-) */
204	break;
205	}
206	}
207	s = NULL;
208	state = NORM;
209	}
210	}
211	return list_arg;
212	}
213	#else
214	/* The variant does not support single quotes, double quotes or backslash */
215	static xlist_t process_stdin(xlist_t list_arg,
216	const char eof_str, size_t mc, char buf)
217	{
218
219	int c; /* current char */
220	int eof_str_detected = 0;
221	char s = NULL; / start word */
222	char p = NULL; / pointer to end word */
223	size_t line_l = 0; /* size loaded args line */
224	xlist_t *cur;
225	xlist_t *prev;
226
227	for (prev = cur = list_arg; cur; cur = cur->link) {
228	line_l += cur->lenght; /* previous allocated */
229	if (prev != cur)
230	prev = prev->link;
231	}
232
233	while (!eof_stdin_detected) {
234	c = getchar();
235	if (c == EOF) {
236	eof_stdin_detected++;
237	}
238	if (eof_str_detected)
239	continue;
240	if (c == EOF \|\| ISSPACE(c)) {
241	if (s == NULL)
242	continue;
243	c = EOF;
244	}
245	if (s == NULL)
246	s = p = buf;
247	if ((p - buf) >= mc)
248	bb_error_msg_and_die("argument line too long");
249	*p++ = c == EOF ? 0 : c;
250	if (c == EOF) { /* word's delimiter or EOF detected */
251	/* word loaded */
252	if (eof_str) {
253	eof_str_detected = strcmp(s, eof_str) == 0;
254	}
255	if (!eof_str_detected) {
256	size_t lenght = (p - buf);
257
258	cur = xmalloc(sizeof(xlist_t) + lenght);
259	cur->data = memcpy(cur + 1, s, lenght);
260	cur->lenght = lenght;
261	cur->link = NULL;
262	if (prev == NULL) {
263	list_arg = cur;
264	} else {
265	prev->link = cur;
266	}
267	prev = cur;
268	line_l += lenght;
269	if (line_l > mc) {
270	/* stop memory usage :-) */
271	break;
272	}
273	s = NULL;
274	}
275	}
276	}
277	return list_arg;
278	}
279	#endif /* CONFIG_FEATURE_XARGS_SUPPORT_QUOTES */
280
281
282	#ifdef CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION
283	/* Prompt the user for a response, and
284	if the user responds affirmatively, return true;
285	otherwise, return false. Used "/dev/tty", not stdin. */
286	static int xargs_ask_confirmation(void)
287	{
288	static FILE *tty_stream;
289	int c, savec;
290
291	if (!tty_stream) {
292	tty_stream = xfopen(CURRENT_TTY, "r");
293	/* pranoidal security by vodz */
294	fcntl(fileno(tty_stream), F_SETFD, FD_CLOEXEC);
295	}
296	fputs(" ?...", stderr);
297	fflush(stderr);
298	c = savec = getc(tty_stream);
299	while (c != EOF && c != '\n')
300	c = getc(tty_stream);
301	if (savec == 'y' \|\| savec == 'Y')
302	return 1;
303	return 0;
304	}
305	#else
306	# define xargs_ask_confirmation() 1
307	#endif /* CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION */
308
309	#ifdef CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM
310	static xlist_t process0_stdin(xlist_t list_arg, const char *eof_str ATTRIBUTE_UNUSED,
311	size_t mc, char *buf)
312	{
313	int c; /* current char */
314	char s = NULL; / start word */
315	char p = NULL; / pointer to end word */
316	size_t line_l = 0; /* size loaded args line */
317	xlist_t *cur;
318	xlist_t *prev;
319
320	for (prev = cur = list_arg; cur; cur = cur->link) {
321	line_l += cur->lenght; /* previous allocated */
322	if (prev != cur)
323	prev = prev->link;
324	}
325
326	while (!eof_stdin_detected) {
327	c = getchar();
328	if (c == EOF) {
329	eof_stdin_detected++;
330	if (s == NULL)
331	break;
332	c = 0;
333	}
334	if (s == NULL)
335	s = p = buf;
336	if ((size_t)(p - buf) >= mc)
337	bb_error_msg_and_die("argument line too long");
338	*p++ = c;
339	if (c == 0) { /* word's delimiter or EOF detected */
340	/* word loaded */
341	size_t lenght = (p - buf);
342
343	cur = xmalloc(sizeof(xlist_t) + lenght);
344	cur->data = memcpy(cur + 1, s, lenght);
345	cur->lenght = lenght;
346	cur->link = NULL;
347	if (prev == NULL) {
348	list_arg = cur;
349	} else {
350	prev->link = cur;
351	}
352	prev = cur;
353	line_l += lenght;
354	if (line_l > mc) {
355	/* stop memory usage :-) */
356	break;
357	}
358	s = NULL;
359	}
360	}
361	return list_arg;
362	}
363	#endif /* CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM */
364
365	/* Correct regardless of combination of CONFIG_xxx */
366	enum {
367	OPTBIT_VERBOSE = 0,
368	OPTBIT_NO_EMPTY,
369	OPTBIT_UPTO_NUMBER,
370	OPTBIT_UPTO_SIZE,
371	OPTBIT_EOF_STRING,
372	USE_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
373	USE_FEATURE_XARGS_SUPPORT_TERMOPT( OPTBIT_TERMINATE ,)
374	USE_FEATURE_XARGS_SUPPORT_ZERO_TERM( OPTBIT_ZEROTERM ,)
375
376	OPT_VERBOSE = 1<<OPTBIT_VERBOSE ,
377	OPT_NO_EMPTY = 1<<OPTBIT_NO_EMPTY ,
378	OPT_UPTO_NUMBER = 1<<OPTBIT_UPTO_NUMBER,
379	OPT_UPTO_SIZE = 1<<OPTBIT_UPTO_SIZE ,
380	OPT_EOF_STRING = 1<<OPTBIT_EOF_STRING ,
381	OPT_INTERACTIVE = USE_FEATURE_XARGS_SUPPORT_CONFIRMATION((1<<OPTBIT_INTERACTIVE)) + 0,
382	OPT_TERMINATE = USE_FEATURE_XARGS_SUPPORT_TERMOPT( (1<<OPTBIT_TERMINATE )) + 0,
383	OPT_ZEROTERM = USE_FEATURE_XARGS_SUPPORT_ZERO_TERM( (1<<OPTBIT_ZEROTERM )) + 0,
384	};
385	#define OPTION_STR "+trn:s:e::" \
386	USE_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
387	USE_FEATURE_XARGS_SUPPORT_TERMOPT( "x") \
388	USE_FEATURE_XARGS_SUPPORT_ZERO_TERM( "0")
389
390	int xargs_main(int argc, char **argv)
391	{
392	char **args;
393	int i, n;
394	xlist_t *list = NULL;
395	xlist_t *cur;
396	int child_error = 0;
397	char max_args, max_chars;
398	int n_max_arg;
399	size_t n_chars = 0;
400	long orig_arg_max;
401	const char *eof_str = "_";
402	unsigned opt;
403	size_t n_max_chars;
404	#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
405	xlist_t* (read_args)(xlist_t, const char, size_t, char) = process_stdin;
406	#else
407	#define read_args process_stdin
408	#endif
409
410	opt = getopt32(argc, argv, OPTION_STR, &max_args, &max_chars, &eof_str);
411
412	if (opt & OPT_ZEROTERM)
413	USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
414
415	argc -= optind;
416	argv += optind;
417	if (!argc) {
418	/* default behavior is to echo all the filenames */
419	*argv = "echo";
420	argc++;
421	}
422
423	orig_arg_max = ARG_MAX;
424	if (orig_arg_max == -1)
425	orig_arg_max = LONG_MAX;
426	orig_arg_max -= 2048; /* POSIX.2 requires subtracting 2048 */
427
428	if (opt & OPT_UPTO_SIZE) {
429	n_max_chars = xatoul_range(max_chars, 1, orig_arg_max);
430	for (i = 0; i < argc; i++) {
431	n_chars += strlen(*argv) + 1;
432	}
433	if (n_max_chars < n_chars) {
434	bb_error_msg_and_die("cannot fit single argument within argument list size limit");
435	}
436	n_max_chars -= n_chars;
437	} else {
438	/* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which
439	have it at 1 meg). Things will work fine with a large ARG_MAX but it
440	will probably hurt the system more than it needs to; an array of this
441	size is allocated. */
442	if (orig_arg_max > 20 * 1024)
443	orig_arg_max = 20 * 1024;
444	n_max_chars = orig_arg_max;
445	}
446	max_chars = xmalloc(n_max_chars);
447
448	if (opt & OPT_UPTO_NUMBER) {
449	n_max_arg = xatoul_range(max_args, 1, INT_MAX);
450	} else {
451	n_max_arg = n_max_chars;
452	}
453
454	while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL \|\|
455	!(opt & OPT_NO_EMPTY))
456	{
457	opt \|= OPT_NO_EMPTY;
458	n = 0;
459	n_chars = 0;
460	#ifdef CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT
461	for (cur = list; cur;) {
462	n_chars += cur->lenght;
463	n++;
464	cur = cur->link;
465	if (n_chars > n_max_chars \|\| (n == n_max_arg && cur)) {
466	if (opt & OPT_TERMINATE)
467	bb_error_msg_and_die("argument list too long");
468	break;
469	}
470	}
471	#else
472	for (cur = list; cur; cur = cur->link) {
473	n_chars += cur->lenght;
474	n++;
475	if (n_chars > n_max_chars \|\| n == n_max_arg) {
476	break;
477	}
478	}
479	#endif /* CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT */
480
481	/* allocate pointers for execvp:
482	argcarg, narg from stdin, NULL */
483	args = xzalloc((n + argc + 1) * sizeof(char *));
484
485	/* store the command to be executed
486	(taken from the command line) */
487	for (i = 0; i < argc; i++)
488	args[i] = argv[i];
489	/* (taken from stdin) */
490	for (cur = list; n; cur = cur->link) {
491	args[i++] = cur->data;
492	n--;
493	}
494
495	if (opt & (OPT_INTERACTIVE \| OPT_VERBOSE)) {
496	for (i = 0; args[i]; i++) {
497	if (i)
498	fputc(' ', stderr);
499	fputs(args[i], stderr);
500	}
501	if (!(opt & OPT_INTERACTIVE))
502	fputc('\n', stderr);
503	}
504	if (!(opt & OPT_INTERACTIVE) \|\| xargs_ask_confirmation()) {
505	child_error = xargs_exec(args);
506	}
507
508	/* clean up */
509	for (i = argc; args[i]; i++) {
510	cur = list;
511	list = list->link;
512	free(cur);
513	}
514	free(args);
515	if (child_error > 0 && child_error != 123) {
516	break;
517	}
518	}
519	if (ENABLE_FEATURE_CLEAN_UP) free(max_chars);
520	return child_error;
521	}
522
523
524	#ifdef TEST
525
526	const char *applet_name = "debug stuff usage";
527
528	void bb_show_usage(void)
529	{
530	fprintf(stderr, "Usage: %s [-p] [-r] [-t] -[x] [-n max_arg] [-s max_chars]\n",
531	applet_name);
532	exit(1);
533	}
534
535	int main(int argc, char **argv)
536	{
537	return xargs_main(argc, argv);
538	}
539	#endif /* TEST */