busybox/libbb/getopt32.c

/* vi: set sw=4 ts=4: */
/*
 * universal getopt32 implementation for busybox
 *
 * Copyright (C) 2003-2005  Vladimir Oleynik  <dzo@simtreas.ru>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include <getopt.h>
#include "libbb.h"

/*      Documentation

uint32_t
getopt32(char **argv, const char *applet_opts, ...)

        The command line options must be declared in const char
        *applet_opts as a string of chars, for example:

        flags = getopt32(argv, "rnug");

        If one of the given options is found, a flag value is added to
        the return value (an unsigned long).

        The flag value is determined by the position of the char in
        applet_opts string.  For example, in the above case:

        flags = getopt32(argv, "rnug");

        "r" will add 1    (bit 0)
        "n" will add 2    (bit 1)
        "u" will add 4    (bit 2)
        "g" will add 8    (bit 3)

        and so on.  You can also look at the return value as a bit
        field and each option sets one bit.

        On exit, global variable optind is set so that if you
        will do argc -= optind; argv += optind; then
        argc will be equal to number of remaining non-option
        arguments, first one would be in argv[0], next in argv[1] and so on
        (options and their parameters will be moved into argv[]
        positions prior to argv[optind]).

 ":"    If one of the options requires an argument, then add a ":"
        after the char in applet_opts and provide a pointer to store
        the argument.  For example:

        char *pointer_to_arg_for_a;
        char *pointer_to_arg_for_b;
        char *pointer_to_arg_for_c;
        char *pointer_to_arg_for_d;

        flags = getopt32(argv, "a:b:c:d:",
                        &pointer_to_arg_for_a, &pointer_to_arg_for_b,
                        &pointer_to_arg_for_c, &pointer_to_arg_for_d);

        The type of the pointer (char* or llist_t*) may be controlled
        by the "::" special separator that is set in the external string
        opt_complementary (see below for more info).

 "::"   If option can have an *optional* argument, then add a "::"
        after its char in applet_opts and provide a pointer to store
        the argument.  Note that optional arguments _must_
        immediately follow the option: -oparam, not -o param.

 "+"    If the first character in the applet_opts string is a plus,
        then option processing will stop as soon as a non-option is
        encountered in the argv array.  Useful for applets like env
        which should not process arguments to subprograms:
        env -i ls -d /
        Here we want env to process just the '-i', not the '-d'.

const char *applet_long_options

        This struct allows you to define long options:

        static const char applet_longopts[] ALIGN1 =
		//"name\0" has_arg val
		"verbose\0" No_argument "v"
		;
        applet_long_options = applet_longopts;

        The last member of struct option (val) typically is set to
        matching short option from applet_opts. If there is no matching
        char in applet_opts, then:
        - return bit have next position after short options
        - if has_arg is not "No_argument", use ptr for arg also
        - opt_complementary affects it too

        Note: a good applet will make long options configurable via the
        config process and not a required feature.  The current standard
        is to name the config option CONFIG_FEATURE_<applet>_LONG_OPTIONS.

const char *opt_complementary

 ":"    The colon (":") is used to separate groups of two or more chars
        and/or groups of chars and special characters (stating some
        conditions to be checked).

 "abc"  If groups of two or more chars are specified, the first char
        is the main option and the other chars are secondary options.
        Their flags will be turned on if the main option is found even
        if they are not specifed on the command line.  For example:

        opt_complementary = "abc";
        flags = getopt32(argv, "abcd")

        If getopt() finds "-a" on the command line, then
        getopt32's return value will be as if "-a -b -c" were
        found.

 "ww"   Adjacent double options have a counter associated which indicates
        the number of occurences of the option.
        For example the ps applet needs:
        if w is given once, GNU ps sets the width to 132,
        if w is given more than once, it is "unlimited"

        int w_counter = 0; // must be initialized!
        opt_complementary = "ww";
        getopt32(argv, "w", &w_counter);
        if (w_counter)
                width = (w_counter == 1) ? 132 : INT_MAX;
        else
                get_terminal_width(...&width...);

        w_counter is a pointer to an integer. It has to be passed to
        getopt32() after all other option argument sinks.

        For example: accept multiple -v to indicate the level of verbosity
        and for each -b optarg, add optarg to my_b. Finally, if b is given,
        turn off c and vice versa:

        llist_t *my_b = NULL;
        int verbose_level = 0;
        opt_complementary = "vv:b::b-c:c-b";
        f = getopt32(argv, "vb:c", &my_b, &verbose_level);
        if (f & 2)       // -c after -b unsets -b flag
                while (my_b) dosomething_with(llist_pop(&my_b));
        if (my_b)        // but llist is stored if -b is specified
                free_llist(my_b);
        if (verbose_level) printf("verbose level is %d\n", verbose_level);

Special characters:

 "-"    A dash as the first char in a opt_complementary group forces
        all arguments to be treated as options, even if they have
        no leading dashes. Next char in this case can't be a digit (0-9),
        use ':' or end of line. For example:

        opt_complementary = "-:w-x:x-w";
        getopt32(argv, "wx");

        Allows any arguments to be given without a dash (./program w x)
        as well as with a dash (./program -x).

	NB: getopt32() will leak a small amount of memory if you use
	this option! Do not use it if there is a possibility of recursive
	getopt32() calls.

 "--"   A double dash at the beginning of opt_complementary means the
        argv[1] string should always be treated as options, even if it isn't
        prefixed with a "-".  This is useful for special syntax in applets
        such as "ar" and "tar":
        tar xvf foo.tar

	NB: getopt32() will leak a small amount of memory if you use
	this option! Do not use it if there is a possibility of recursive
	getopt32() calls.

 "-N"   A dash as the first char in a opt_complementary group followed
        by a single digit (0-9) means that at least N non-option
        arguments must be present on the command line

 "=N"   An equal sign as the first char in a opt_complementary group followed
        by a single digit (0-9) means that exactly N non-option
        arguments must be present on the command line

 "?N"   A "?" as the first char in a opt_complementary group followed
        by a single digit (0-9) means that at most N arguments must be present
        on the command line.

 "V-"   An option with dash before colon or end-of-line results in
        bb_show_usage() being called if this option is encountered.
        This is typically used to implement "print verbose usage message
        and exit" option.

 "a-b"  A dash between two options causes the second of the two
        to be unset (and ignored) if it is given on the command line.

        [FIXME: what if they are the same? like "x-x"? Is it ever useful?]

        For example:
        The du applet has the options "-s" and "-d depth".  If
        getopt32 finds -s, then -d is unset or if it finds -d
        then -s is unset.  (Note:  busybox implements the GNU
        "--max-depth" option as "-d".)  To obtain this behavior, you
        set opt_complementary = "s-d:d-s".  Only one flag value is
        added to getopt32's return value depending on the
        position of the options on the command line.  If one of the
        two options requires an argument pointer (":" in applet_opts
        as in "d:") optarg is set accordingly.

        char *smax_print_depth;

        opt_complementary = "s-d:d-s:x-x";
        opt = getopt32(argv, "sd:x", &smax_print_depth);

        if (opt & 2)
                max_print_depth = atoi(smax_print_depth);
        if (opt & 4)
                printf("Detected odd -x usage\n");

 "a--b" A double dash between two options, or between an option and a group
        of options, means that they are mutually exclusive.  Unlike
        the "-" case above, an error will be forced if the options
        are used together.

        For example:
        The cut applet must have only one type of list specified, so
        -b, -c and -f are mutually exclusive and should raise an error
        if specified together.  In this case you must set
        opt_complementary = "b--cf:c--bf:f--bc".  If two of the
        mutually exclusive options are found, getopt32 will call
	bb_show_usage() and die.

 "x--x" Variation of the above, it means that -x option should occur
        at most once.

 "a+"   A plus after a char in opt_complementary means that the parameter
        for this option is a nonnegative integer. It will be processed
        with xatoi_u() - allowed range is 0..INT_MAX.

        int param;  // "unsigned param;" will also work
        opt_complementary = "p+";
        getopt32(argv, "p:", &param);

 "a::"  A double colon after a char in opt_complementary means that the
        option can occur multiple times. Each occurrence will be saved as
        a llist_t element instead of char*.

        For example:
        The grep applet can have one or more "-e pattern" arguments.
        In this case you should use getopt32() as follows:

        llist_t *patterns = NULL;

        (this pointer must be initializated to NULL if the list is empty
        as required by llist_add_to_end(llist_t **old_head, char *new_item).)

        opt_complementary = "e::";

        getopt32(argv, "e:", &patterns);
        $ grep -e user -e root /etc/passwd
        root:x:0:0:root:/root:/bin/bash
        user:x:500:500::/home/user:/bin/bash

 "a?b"  A "?" between an option and a group of options means that
        at least one of them is required to occur if the first option
        occurs in preceding command line arguments.

        For example from "id" applet:

        // Don't allow -n -r -rn -ug -rug -nug -rnug
        opt_complementary = "r?ug:n?ug:u--g:g--u";
        flags = getopt32(argv, "rnug");

        This example allowed only:
        $ id; id -u; id -g; id -ru; id -nu; id -rg; id -ng; id -rnu; id -rng

 "X"    A opt_complementary group with just a single letter means
        that this option is required. If more than one such group exists,
        at least one option is required to occur (not all of them).
        For example from "start-stop-daemon" applet:

        // Don't allow -KS -SK, but -S or -K is required
        opt_complementary = "K:S:K--S:S--K";
        flags = getopt32(argv, "KS...);


        Don't forget to use ':'. For example, "?322-22-23X-x-a"
        is interpreted as "?3:22:-2:2-2:2-3Xa:2--x" -
        max 3 args; count uses of '-2'; min 2 args; if there is
        a '-2' option then unset '-3', '-X' and '-a'; if there is
        a '-2' and after it a '-x' then error out.
        But it's far too obfuscated. Use ':' to separate groups.
*/

/* Code here assumes that 'unsigned' is at least 32 bits wide */

const char *const bb_argv_dash[] = { "-", NULL };

const char *opt_complementary;

enum {
	PARAM_STRING,
	PARAM_LIST,
	PARAM_INT,
};

typedef struct {
	unsigned char opt_char;
	smallint param_type;
	unsigned switch_on;
	unsigned switch_off;
	unsigned incongruously;
	unsigned requires;
	void **optarg;  /* char**, llist_t** or int *. */
	int *counter;
} t_complementary;

/* You can set applet_long_options for parse called long options */
#if ENABLE_GETOPT_LONG
static const struct option bb_null_long_options[1] = {
	{ 0, 0, 0, 0 }
};
const char *applet_long_options;
#endif

uint32_t option_mask32;

uint32_t FAST_FUNC
getopt32(char **argv, const char *applet_opts, ...)
{
	int argc;
	unsigned flags = 0;
	unsigned requires = 0;
	t_complementary complementary[33]; /* last stays zero-filled */
	int c;
	const unsigned char *s;
	t_complementary *on_off;
	va_list p;
#if ENABLE_GETOPT_LONG
	const struct option *l_o;
	struct option *long_options = (struct option *) &bb_null_long_options;
#endif
	unsigned trigger;
	char **pargv;
	int min_arg = 0;
	int max_arg = -1;

#define SHOW_USAGE_IF_ERROR     1
#define ALL_ARGV_IS_OPTS        2
#define FIRST_ARGV_IS_OPT       4

	int spec_flgs = 0;

	/* skip 0: some applets cheat: they do not actually HAVE argv[0] */
	argc = 1;
	while (argv[argc])
		argc++;

	va_start(p, applet_opts);

	c = 0;
	on_off = complementary;
	memset(on_off, 0, sizeof(complementary));

	/* skip GNU extension */
	s = (const unsigned char *)applet_opts;
	if (*s == '+' || *s == '-')
		s++;
	while (*s) {
		if (c >= 32)
			break;
		on_off->opt_char = *s;
		on_off->switch_on = (1 << c);
		if (*++s == ':') {
			on_off->optarg = va_arg(p, void **);
			while (*++s == ':')
				continue;
		}
		on_off++;
		c++;
	}

#if ENABLE_GETOPT_LONG
	if (applet_long_options) {
		const char *optstr;
		unsigned i, count;

		count = 1;
		optstr = applet_long_options;
		while (optstr[0]) {
			optstr += strlen(optstr) + 3; /* skip NUL, has_arg, val */
			count++;
		}
		/* count == no. of longopts + 1 */
		long_options = alloca(count * sizeof(*long_options));
		memset(long_options, 0, count * sizeof(*long_options));
		i = 0;
		optstr = applet_long_options;
		while (--count) {
			long_options[i].name = optstr;
			optstr += strlen(optstr) + 1;
			long_options[i].has_arg = (unsigned char)(*optstr++);
			/* long_options[i].flag = NULL; */
			long_options[i].val = (unsigned char)(*optstr++);
			i++;
		}
		for (l_o = long_options; l_o->name; l_o++) {
			if (l_o->flag)
				continue;
			for (on_off = complementary; on_off->opt_char; on_off++)
				if (on_off->opt_char == l_o->val)
					goto next_long;
			if (c >= 32)
				break;
			on_off->opt_char = l_o->val;
			on_off->switch_on = (1 << c);
			if (l_o->has_arg != no_argument)
				on_off->optarg = va_arg(p, void **);
			c++;
 next_long: ;
		}
	}
#endif /* ENABLE_GETOPT_LONG */
	for (s = (const unsigned char *)opt_complementary; s && *s; s++) {
		t_complementary *pair;
		unsigned *pair_switch;

		if (*s == ':')
			continue;
		c = s[1];
		if (*s == '?') {
			if (c < '0' || c > '9') {
				spec_flgs |= SHOW_USAGE_IF_ERROR;
			} else {
				max_arg = c - '0';
				s++;
			}
			continue;
		}
		if (*s == '-') {
			if (c < '0' || c > '9') {
				if (c == '-') {
					spec_flgs |= FIRST_ARGV_IS_OPT;
					s++;
				} else
					spec_flgs |= ALL_ARGV_IS_OPTS;
			} else {
				min_arg = c - '0';
				s++;
			}
			continue;
		}
		if (*s == '=') {
			min_arg = max_arg = c - '0';
			s++;
			continue;
		}
		for (on_off = complementary; on_off->opt_char; on_off++)
			if (on_off->opt_char == *s)
				break;
		if (c == ':' && s[2] == ':') {
			on_off->param_type = PARAM_LIST;
			continue;
		}
		if (c == '+' && (s[2] == ':' || s[2] == '\0')) {
			on_off->param_type = PARAM_INT;
			continue;
		}
		if (c == ':' || c == '\0') {
			requires |= on_off->switch_on;
			continue;
		}
		if (c == '-' && (s[2] == ':' || s[2] == '\0')) {
			flags |= on_off->switch_on;
			on_off->incongruously |= on_off->switch_on;
			s++;
			continue;
		}
		if (c == *s) {
			on_off->counter = va_arg(p, int *);
			s++;
		}
		pair = on_off;
		pair_switch = &(pair->switch_on);
		for (s++; *s && *s != ':'; s++) {
			if (*s == '?') {
				pair_switch = &(pair->requires);
			} else if (*s == '-') {
				if (pair_switch == &(pair->switch_off))
					pair_switch = &(pair->incongruously);
				else
					pair_switch = &(pair->switch_off);
			} else {
				for (on_off = complementary; on_off->opt_char; on_off++)
					if (on_off->opt_char == *s) {
						*pair_switch |= on_off->switch_on;
						break;
					}
			}
		}
		s--;
	}
	va_end(p);

	if (spec_flgs & (FIRST_ARGV_IS_OPT | ALL_ARGV_IS_OPTS)) {
		pargv = argv + 1;
		while (*pargv) {
			if (pargv[0][0] != '-' && pargv[0][0] != '\0') {
				/* Can't use alloca: opts with params will
				 * return pointers to stack!
				 * NB: we leak these allocations... */
				char *pp = xmalloc(strlen(*pargv) + 2);
				*pp = '-';
				strcpy(pp + 1, *pargv);
				*pargv = pp;
			}
			if (!(spec_flgs & ALL_ARGV_IS_OPTS))
				break;
			pargv++;
		}
	}

	/* In case getopt32 was already called:
	 * reset the libc getopt() function, which keeps internal state.
	 * run_nofork_applet_prime() does this, but we might end up here
	 * also via gunzip_main() -> gzip_main(). Play safe.
	 */
#ifdef __GLIBC__
	optind = 0;
#else /* BSD style */
	optind = 1;
	/* optreset = 1; */
#endif
	/* optarg = NULL; opterr = 0; optopt = 0; - do we need this?? */

	pargv = NULL;

	/* Note: just "getopt() <= 0" will not work well for
	 * "fake" short options, like this one:
	 * wget $'-\203' "Test: test" http://kernel.org/
	 * (supposed to act as --header, but doesn't) */
#if ENABLE_GETOPT_LONG
	while ((c = getopt_long(argc, argv, applet_opts,
			long_options, NULL)) != -1) {
#else
	while ((c = getopt(argc, argv, applet_opts)) != -1) {
#endif
		/* getopt prints "option requires an argument -- X"
		 * and returns '?' if an option has no arg, but one is reqd */
		c &= 0xff; /* fight libc's sign extension */
		for (on_off = complementary; on_off->opt_char != c; on_off++) {
			/* c can be NUL if long opt has non-NULL ->flag,
			 * but we construct long opts so that flag
			 * is always NULL (see above) */
			if (on_off->opt_char == '\0' /* && c != '\0' */) {
				/* c is probably '?' - "bad option" */
				bb_show_usage();
			}
		}
		if (flags & on_off->incongruously)
			bb_show_usage();
		trigger = on_off->switch_on & on_off->switch_off;
		flags &= ~(on_off->switch_off ^ trigger);
		flags |= on_off->switch_on ^ trigger;
		flags ^= trigger;
		if (on_off->counter)
			(*(on_off->counter))++;
		if (on_off->param_type == PARAM_LIST) {
			if (optarg)
				llist_add_to_end((llist_t **)(on_off->optarg), optarg);
		} else if (on_off->param_type == PARAM_INT) {
			if (optarg)
//TODO: xatoi_u indirectly pulls in printf machinery
				*(unsigned*)(on_off->optarg) = xatoi_u(optarg);
		} else if (on_off->optarg) {
			if (optarg)
				*(char **)(on_off->optarg) = optarg;
		}
		if (pargv != NULL)
			break;
	}

	/* check depending requires for given options */
	for (on_off = complementary; on_off->opt_char; on_off++) {
		if (on_off->requires && (flags & on_off->switch_on) &&
					(flags & on_off->requires) == 0)
			bb_show_usage();
	}
	if (requires && (flags & requires) == 0)
		bb_show_usage();
	argc -= optind;
	if (argc < min_arg || (max_arg >= 0 && argc > max_arg))
		bb_show_usage();

	option_mask32 = flags;
	return flags;
}
1	niro	532	/* vi: set sw=4 ts=4: */
2			/*
3			* universal getopt32 implementation for busybox
4			*
5			* Copyright (C) 2003-2005 Vladimir Oleynik <dzo@simtreas.ru>
6			*
7			* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8			*/
9
10	niro	816	#include <getopt.h>
11	niro	532	#include "libbb.h"
12
13			/* Documentation
14
15			uint32_t
16	niro	816	getopt32(char *argv, const char applet_opts, ...)
17	niro	532
18			The command line options must be declared in const char
19			*applet_opts as a string of chars, for example:
20
21	niro	816	flags = getopt32(argv, "rnug");
22	niro	532
23			If one of the given options is found, a flag value is added to
24			the return value (an unsigned long).
25
26			The flag value is determined by the position of the char in
27			applet_opts string. For example, in the above case:
28
29	niro	816	flags = getopt32(argv, "rnug");
30	niro	532
31			"r" will add 1 (bit 0)
32			"n" will add 2 (bit 1)
33	niro	816	"u" will add 4 (bit 2)
34	niro	532	"g" will add 8 (bit 3)
35
36			and so on. You can also look at the return value as a bit
37			field and each option sets one bit.
38
39			On exit, global variable optind is set so that if you
40			will do argc -= optind; argv += optind; then
41			argc will be equal to number of remaining non-option
42			arguments, first one would be in argv[0], next in argv[1] and so on
43			(options and their parameters will be moved into argv[]
44			positions prior to argv[optind]).
45
46			":" If one of the options requires an argument, then add a ":"
47			after the char in applet_opts and provide a pointer to store
48			the argument. For example:
49
50			char *pointer_to_arg_for_a;
51			char *pointer_to_arg_for_b;
52			char *pointer_to_arg_for_c;
53			char *pointer_to_arg_for_d;
54
55	niro	816	flags = getopt32(argv, "a:b:c:d:",
56			&pointer_to_arg_for_a, &pointer_to_arg_for_b,
57			&pointer_to_arg_for_c, &pointer_to_arg_for_d);
58	niro	532
59			The type of the pointer (char* or llist_t*) may be controlled
60			by the "::" special separator that is set in the external string
61			opt_complementary (see below for more info).
62
63			"::" If option can have an optional argument, then add a "::"
64			after its char in applet_opts and provide a pointer to store
65			the argument. Note that optional arguments _must_
66			immediately follow the option: -oparam, not -o param.
67
68			"+" If the first character in the applet_opts string is a plus,
69			then option processing will stop as soon as a non-option is
70			encountered in the argv array. Useful for applets like env
71			which should not process arguments to subprograms:
72			env -i ls -d /
73			Here we want env to process just the '-i', not the '-d'.
74
75	niro	816	const char *applet_long_options
76	niro	532
77	niro	816	This struct allows you to define long options:
78	niro	532
79	niro	816	static const char applet_longopts[] ALIGN1 =
80			//"name\0" has_arg val
81			"verbose\0" No_argument "v"
82			;
83			applet_long_options = applet_longopts;
84	niro	532
85			The last member of struct option (val) typically is set to
86			matching short option from applet_opts. If there is no matching
87			char in applet_opts, then:
88			- return bit have next position after short options
89	niro	816	- if has_arg is not "No_argument", use ptr for arg also
90	niro	532	- opt_complementary affects it too
91
92			Note: a good applet will make long options configurable via the
93			config process and not a required feature. The current standard
94			is to name the config option CONFIG_FEATURE_<applet>_LONG_OPTIONS.
95
96			const char *opt_complementary
97
98			":" The colon (":") is used to separate groups of two or more chars
99			and/or groups of chars and special characters (stating some
100			conditions to be checked).
101
102			"abc" If groups of two or more chars are specified, the first char
103			is the main option and the other chars are secondary options.
104			Their flags will be turned on if the main option is found even
105			if they are not specifed on the command line. For example:
106
107			opt_complementary = "abc";
108	niro	816	flags = getopt32(argv, "abcd")
109	niro	532
110			If getopt() finds "-a" on the command line, then
111			getopt32's return value will be as if "-a -b -c" were
112			found.
113
114			"ww" Adjacent double options have a counter associated which indicates
115			the number of occurences of the option.
116			For example the ps applet needs:
117			if w is given once, GNU ps sets the width to 132,
118			if w is given more than once, it is "unlimited"
119
120	niro	816	int w_counter = 0; // must be initialized!
121	niro	532	opt_complementary = "ww";
122	niro	816	getopt32(argv, "w", &w_counter);
123	niro	532	if (w_counter)
124	niro	816	width = (w_counter == 1) ? 132 : INT_MAX;
125	niro	532	else
126	niro	816	get_terminal_width(...&width...);
127	niro	532
128			w_counter is a pointer to an integer. It has to be passed to
129			getopt32() after all other option argument sinks.
130
131			For example: accept multiple -v to indicate the level of verbosity
132			and for each -b optarg, add optarg to my_b. Finally, if b is given,
133			turn off c and vice versa:
134
135			llist_t *my_b = NULL;
136			int verbose_level = 0;
137			opt_complementary = "vv:b::b-c:c-b";
138	niro	816	f = getopt32(argv, "vb:c", &my_b, &verbose_level);
139	niro	532	if (f & 2) // -c after -b unsets -b flag
140	niro	816	while (my_b) dosomething_with(llist_pop(&my_b));
141	niro	532	if (my_b) // but llist is stored if -b is specified
142	niro	816	free_llist(my_b);
143	niro	532	if (verbose_level) printf("verbose level is %d\n", verbose_level);
144
145			Special characters:
146
147			"-" A dash as the first char in a opt_complementary group forces
148			all arguments to be treated as options, even if they have
149			no leading dashes. Next char in this case can't be a digit (0-9),
150			use ':' or end of line. For example:
151
152			opt_complementary = "-:w-x:x-w";
153	niro	816	getopt32(argv, "wx");
154	niro	532
155			Allows any arguments to be given without a dash (./program w x)
156			as well as with a dash (./program -x).
157
158	niro	816	NB: getopt32() will leak a small amount of memory if you use
159			this option! Do not use it if there is a possibility of recursive
160			getopt32() calls.
161
162	niro	532	"--" A double dash at the beginning of opt_complementary means the
163			argv[1] string should always be treated as options, even if it isn't
164			prefixed with a "-". This is useful for special syntax in applets
165			such as "ar" and "tar":
166			tar xvf foo.tar
167
168	niro	816	NB: getopt32() will leak a small amount of memory if you use
169			this option! Do not use it if there is a possibility of recursive
170			getopt32() calls.
171
172	niro	532	"-N" A dash as the first char in a opt_complementary group followed
173			by a single digit (0-9) means that at least N non-option
174			arguments must be present on the command line
175
176			"=N" An equal sign as the first char in a opt_complementary group followed
177			by a single digit (0-9) means that exactly N non-option
178			arguments must be present on the command line
179
180			"?N" A "?" as the first char in a opt_complementary group followed
181			by a single digit (0-9) means that at most N arguments must be present
182			on the command line.
183
184			"V-" An option with dash before colon or end-of-line results in
185	niro	816	bb_show_usage() being called if this option is encountered.
186	niro	532	This is typically used to implement "print verbose usage message
187			and exit" option.
188
189	niro	816	"a-b" A dash between two options causes the second of the two
190	niro	532	to be unset (and ignored) if it is given on the command line.
191
192			[FIXME: what if they are the same? like "x-x"? Is it ever useful?]
193
194			For example:
195			The du applet has the options "-s" and "-d depth". If
196			getopt32 finds -s, then -d is unset or if it finds -d
197			then -s is unset. (Note: busybox implements the GNU
198			"--max-depth" option as "-d".) To obtain this behavior, you
199			set opt_complementary = "s-d:d-s". Only one flag value is
200			added to getopt32's return value depending on the
201			position of the options on the command line. If one of the
202			two options requires an argument pointer (":" in applet_opts
203			as in "d:") optarg is set accordingly.
204
205			char *smax_print_depth;
206
207			opt_complementary = "s-d:d-s:x-x";
208	niro	816	opt = getopt32(argv, "sd:x", &smax_print_depth);
209	niro	532
210			if (opt & 2)
211	niro	816	max_print_depth = atoi(smax_print_depth);
212	niro	532	if (opt & 4)
213	niro	816	printf("Detected odd -x usage\n");
214	niro	532
215	niro	816	"a--b" A double dash between two options, or between an option and a group
216	niro	532	of options, means that they are mutually exclusive. Unlike
217			the "-" case above, an error will be forced if the options
218			are used together.
219
220			For example:
221			The cut applet must have only one type of list specified, so
222	niro	816	-b, -c and -f are mutually exclusive and should raise an error
223	niro	532	if specified together. In this case you must set
224			opt_complementary = "b--cf:c--bf:f--bc". If two of the
225	niro	816	mutually exclusive options are found, getopt32 will call
226			bb_show_usage() and die.
227	niro	532
228			"x--x" Variation of the above, it means that -x option should occur
229			at most once.
230
231	niro	816	"a+" A plus after a char in opt_complementary means that the parameter
232			for this option is a nonnegative integer. It will be processed
233			with xatoi_u() - allowed range is 0..INT_MAX.
234	niro	532
235	niro	816	int param; // "unsigned param;" will also work
236			opt_complementary = "p+";
237			getopt32(argv, "p:", &param);
238
239			"a::" A double colon after a char in opt_complementary means that the
240	niro	532	option can occur multiple times. Each occurrence will be saved as
241			a llist_t element instead of char*.
242
243			For example:
244			The grep applet can have one or more "-e pattern" arguments.
245			In this case you should use getopt32() as follows:
246
247			llist_t *patterns = NULL;
248
249			(this pointer must be initializated to NULL if the list is empty
250	niro	816	as required by llist_add_to_end(llist_t *old_head, char new_item).)
251	niro	532
252			opt_complementary = "e::";
253
254	niro	816	getopt32(argv, "e:", &patterns);
255	niro	532	$ grep -e user -e root /etc/passwd
256			root:x:0:0:root:/root:/bin/bash
257			user:x:500:500::/home/user:/bin/bash
258
259	niro	816	"a?b" A "?" between an option and a group of options means that
260	niro	532	at least one of them is required to occur if the first option
261			occurs in preceding command line arguments.
262
263			For example from "id" applet:
264
265			// Don't allow -n -r -rn -ug -rug -nug -rnug
266	niro	816	opt_complementary = "r?ug:n?ug:u--g:g--u";
267			flags = getopt32(argv, "rnug");
268	niro	532
269			This example allowed only:
270			$ id; id -u; id -g; id -ru; id -nu; id -rg; id -ng; id -rnu; id -rng
271
272			"X" A opt_complementary group with just a single letter means
273			that this option is required. If more than one such group exists,
274			at least one option is required to occur (not all of them).
275			For example from "start-stop-daemon" applet:
276
277			// Don't allow -KS -SK, but -S or -K is required
278	niro	816	opt_complementary = "K:S:K--S:S--K";
279			flags = getopt32(argv, "KS...);
280	niro	532
281
282			Don't forget to use ':'. For example, "?322-22-23X-x-a"
283			is interpreted as "?3:22:-2:2-2:2-3Xa:2--x" -
284			max 3 args; count uses of '-2'; min 2 args; if there is
285			a '-2' option then unset '-3', '-X' and '-a'; if there is
286			a '-2' and after it a '-x' then error out.
287	niro	816	But it's far too obfuscated. Use ':' to separate groups.
288	niro	532	*/
289
290			/* Code here assumes that 'unsigned' is at least 32 bits wide */
291
292	niro	816	const char *const bb_argv_dash[] = { "-", NULL };
293
294	niro	532	const char *opt_complementary;
295
296	niro	816	enum {
297			PARAM_STRING,
298			PARAM_LIST,
299			PARAM_INT,
300			};
301
302	niro	532	typedef struct {
303	niro	816	unsigned char opt_char;
304			smallint param_type;
305	niro	532	unsigned switch_on;
306			unsigned switch_off;
307			unsigned incongruously;
308			unsigned requires;
309	niro	816	void *optarg; / char, llist_t or int . /
310	niro	532	int *counter;
311			} t_complementary;
312
313			/* You can set applet_long_options for parse called long options */
314			#if ENABLE_GETOPT_LONG
315	niro	816	static const struct option bb_null_long_options[1] = {
316	niro	532	{ 0, 0, 0, 0 }
317			};
318	niro	816	const char *applet_long_options;
319	niro	532	#endif
320
321			uint32_t option_mask32;
322
323	niro	816	uint32_t FAST_FUNC
324			getopt32(char *argv, const char applet_opts, ...)
325	niro	532	{
326	niro	816	int argc;
327	niro	532	unsigned flags = 0;
328			unsigned requires = 0;
329	niro	816	t_complementary complementary[33]; /* last stays zero-filled */
330	niro	532	int c;
331			const unsigned char *s;
332			t_complementary *on_off;
333			va_list p;
334			#if ENABLE_GETOPT_LONG
335			const struct option *l_o;
336	niro	816	struct option long_options = (struct option ) &bb_null_long_options;
337	niro	532	#endif
338			unsigned trigger;
339	niro	816	char **pargv;
340	niro	532	int min_arg = 0;
341			int max_arg = -1;
342
343			#define SHOW_USAGE_IF_ERROR 1
344			#define ALL_ARGV_IS_OPTS 2
345			#define FIRST_ARGV_IS_OPT 4
346	niro	816
347	niro	532	int spec_flgs = 0;
348
349	niro	816	/* skip 0: some applets cheat: they do not actually HAVE argv[0] */
350			argc = 1;
351			while (argv[argc])
352			argc++;
353
354	niro	532	va_start(p, applet_opts);
355
356			c = 0;
357			on_off = complementary;
358			memset(on_off, 0, sizeof(complementary));
359
360			/* skip GNU extension */
361			s = (const unsigned char *)applet_opts;
362			if (s == '+' \|\| s == '-')
363			s++;
364			while (*s) {
365	niro	816	if (c >= 32)
366			break;
367			on_off->opt_char = *s;
368	niro	532	on_off->switch_on = (1 << c);
369			if (*++s == ':') {
370			on_off->optarg = va_arg(p, void **);
371	niro	816	while (*++s == ':')
372			continue;
373	niro	532	}
374			on_off++;
375			c++;
376			}
377
378			#if ENABLE_GETOPT_LONG
379	niro	816	if (applet_long_options) {
380			const char *optstr;
381			unsigned i, count;
382
383			count = 1;
384			optstr = applet_long_options;
385			while (optstr[0]) {
386			optstr += strlen(optstr) + 3; /* skip NUL, has_arg, val */
387			count++;
388			}
389			/* count == no. of longopts + 1 */
390			long_options = alloca(count * sizeof(*long_options));
391			memset(long_options, 0, count * sizeof(*long_options));
392			i = 0;
393			optstr = applet_long_options;
394			while (--count) {
395			long_options[i].name = optstr;
396			optstr += strlen(optstr) + 1;
397			long_options[i].has_arg = (unsigned char)(*optstr++);
398			/* long_options[i].flag = NULL; */
399			long_options[i].val = (unsigned char)(*optstr++);
400			i++;
401			}
402			for (l_o = long_options; l_o->name; l_o++) {
403			if (l_o->flag)
404			continue;
405			for (on_off = complementary; on_off->opt_char; on_off++)
406			if (on_off->opt_char == l_o->val)
407			goto next_long;
408			if (c >= 32)
409			break;
410			on_off->opt_char = l_o->val;
411			on_off->switch_on = (1 << c);
412			if (l_o->has_arg != no_argument)
413			on_off->optarg = va_arg(p, void **);
414			c++;
415	niro	532	next_long: ;
416	niro	816	}
417	niro	532	}
418			#endif /* ENABLE_GETOPT_LONG */
419			for (s = (const unsigned char )opt_complementary; s && s; s++) {
420			t_complementary *pair;
421			unsigned *pair_switch;
422
423			if (*s == ':')
424			continue;
425			c = s[1];
426			if (*s == '?') {
427			if (c < '0' \|\| c > '9') {
428			spec_flgs \|= SHOW_USAGE_IF_ERROR;
429			} else {
430			max_arg = c - '0';
431			s++;
432			}
433			continue;
434			}
435			if (*s == '-') {
436			if (c < '0' \|\| c > '9') {
437			if (c == '-') {
438			spec_flgs \|= FIRST_ARGV_IS_OPT;
439			s++;
440			} else
441			spec_flgs \|= ALL_ARGV_IS_OPTS;
442			} else {
443			min_arg = c - '0';
444			s++;
445			}
446			continue;
447			}
448			if (*s == '=') {
449			min_arg = max_arg = c - '0';
450			s++;
451			continue;
452			}
453	niro	816	for (on_off = complementary; on_off->opt_char; on_off++)
454			if (on_off->opt_char == *s)
455	niro	532	break;
456			if (c == ':' && s[2] == ':') {
457	niro	816	on_off->param_type = PARAM_LIST;
458	niro	532	continue;
459			}
460	niro	816	if (c == '+' && (s[2] == ':' \|\| s[2] == '\0')) {
461			on_off->param_type = PARAM_INT;
462			continue;
463			}
464	niro	532	if (c == ':' \|\| c == '\0') {
465			requires \|= on_off->switch_on;
466			continue;
467			}
468			if (c == '-' && (s[2] == ':' \|\| s[2] == '\0')) {
469			flags \|= on_off->switch_on;
470			on_off->incongruously \|= on_off->switch_on;
471			s++;
472			continue;
473			}
474			if (c == *s) {
475			on_off->counter = va_arg(p, int *);
476			s++;
477			}
478			pair = on_off;
479			pair_switch = &(pair->switch_on);
480			for (s++; s && s != ':'; s++) {
481			if (*s == '?') {
482			pair_switch = &(pair->requires);
483			} else if (*s == '-') {
484			if (pair_switch == &(pair->switch_off))
485			pair_switch = &(pair->incongruously);
486			else
487			pair_switch = &(pair->switch_off);
488			} else {
489	niro	816	for (on_off = complementary; on_off->opt_char; on_off++)
490			if (on_off->opt_char == *s) {
491	niro	532	*pair_switch \|= on_off->switch_on;
492			break;
493			}
494			}
495			}
496			s--;
497			}
498	niro	816	va_end(p);
499	niro	532
500	niro	816	if (spec_flgs & (FIRST_ARGV_IS_OPT \| ALL_ARGV_IS_OPTS)) {
501			pargv = argv + 1;
502			while (*pargv) {
503			if (pargv[0][0] != '-' && pargv[0][0] != '\0') {
504			/* Can't use alloca: opts with params will
505			* return pointers to stack!
506			* NB: we leak these allocations... */
507			char pp = xmalloc(strlen(pargv) + 2);
508			*pp = '-';
509			strcpy(pp + 1, *pargv);
510			*pargv = pp;
511			}
512			if (!(spec_flgs & ALL_ARGV_IS_OPTS))
513			break;
514			pargv++;
515	niro	532	}
516			}
517	niro	816
518			/* In case getopt32 was already called:
519			* reset the libc getopt() function, which keeps internal state.
520			* run_nofork_applet_prime() does this, but we might end up here
521			* also via gunzip_main() -> gzip_main(). Play safe.
522			*/
523			#ifdef __GLIBC__
524			optind = 0;
525			#else /* BSD style */
526			optind = 1;
527			/* optreset = 1; */
528			#endif
529			/* optarg = NULL; opterr = 0; optopt = 0; - do we need this?? */
530
531			pargv = NULL;
532
533			/* Note: just "getopt() <= 0" will not work well for
534	niro	532	* "fake" short options, like this one:
535			* wget $'-\203' "Test: test" http://kernel.org/
536			* (supposed to act as --header, but doesn't) */
537			#if ENABLE_GETOPT_LONG
538			while ((c = getopt_long(argc, argv, applet_opts,
539	niro	816	long_options, NULL)) != -1) {
540	niro	532	#else
541			while ((c = getopt(argc, argv, applet_opts)) != -1) {
542	niro	816	#endif
543			/* getopt prints "option requires an argument -- X"
544			* and returns '?' if an option has no arg, but one is reqd */
545			c &= 0xff; /* fight libc's sign extension */
546			for (on_off = complementary; on_off->opt_char != c; on_off++) {
547			/* c can be NUL if long opt has non-NULL ->flag,
548			* but we construct long opts so that flag
549			* is always NULL (see above) */
550			if (on_off->opt_char == '\0' /* && c != '\0' */) {
551			/* c is probably '?' - "bad option" */
552	niro	532	bb_show_usage();
553	niro	816	}
554	niro	532	}
555	niro	816	if (flags & on_off->incongruously)
556			bb_show_usage();
557	niro	532	trigger = on_off->switch_on & on_off->switch_off;
558			flags &= ~(on_off->switch_off ^ trigger);
559			flags \|= on_off->switch_on ^ trigger;
560			flags ^= trigger;
561			if (on_off->counter)
562			(*(on_off->counter))++;
563	niro	816	if (on_off->param_type == PARAM_LIST) {
564			if (optarg)
565			llist_add_to_end((llist_t **)(on_off->optarg), optarg);
566			} else if (on_off->param_type == PARAM_INT) {
567			if (optarg)
568			//TODO: xatoi_u indirectly pulls in printf machinery
569			(unsigned)(on_off->optarg) = xatoi_u(optarg);
570	niro	532	} else if (on_off->optarg) {
571	niro	816	if (optarg)
572			(char *)(on_off->optarg) = optarg;
573	niro	532	}
574			if (pargv != NULL)
575			break;
576			}
577
578			/* check depending requires for given options */
579	niro	816	for (on_off = complementary; on_off->opt_char; on_off++) {
580	niro	532	if (on_off->requires && (flags & on_off->switch_on) &&
581			(flags & on_off->requires) == 0)
582			bb_show_usage();
583			}
584			if (requires && (flags & requires) == 0)
585			bb_show_usage();
586			argc -= optind;
587			if (argc < min_arg \|\| (max_arg >= 0 && argc > max_arg))
588			bb_show_usage();
589
590			option_mask32 = flags;
591			return flags;
592			}