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

/*      Documentation

uint32_t
getopt32(int argc, 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(argc, 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(argc, 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(argc, 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 struct option *applet_long_options

        This struct allows you to define long options.  The syntax for
        declaring the array is just like that of getopt's longopts.
        (see getopt(3))

        static const struct option applet_long_options[] = {
        	//name,has_arg,flag,val
        	{ "verbose", 0, 0, 'v' },
        	{ 0, 0, 0, 0 }
        };
        applet_long_options = applet_long_options;

        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(argc, 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;
        opt_complementary = "ww";
        getopt32(argc, 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(argc, argv, "vb:c", &my_b, &verbose_level);
        if (f & 2)       // -c after -b unsets -b flag
        	while (my_b) { dosomething_with(my_b->data); my_b = my_b->link; }
        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(argc, argv, "wx");

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

 "--"   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

 "-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 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(argc, 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 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 mutally 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's
        return value will have the error flag set (BB_GETOPT_ERROR) so
        that we can check for it:

        if (flags & BB_GETOPT_ERROR)
        	bb_show_usage();

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

 "?"    A "?" as the first char in a opt_complementary group means:
        if BB_GETOPT_ERROR is detected, don't return, call bb_show_usage
        and exit instead. Next char after '?' can't be a digit.

 "::"   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(llist_t *old_head, char *new_item).)

        opt_complementary = "e::";

        getopt32(argc, 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

 "?"    An "?" 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(argc, 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(argc, 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.
*/

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

const char *opt_complementary;

typedef struct {
	int opt;
	int list_flg;
	unsigned switch_on;
	unsigned switch_off;
	unsigned incongruously;
	unsigned requires;
	void **optarg;               /* char **optarg or llist_t **optarg */
	int *counter;
} t_complementary;

/* You can set applet_long_options for parse called long options */
#if ENABLE_GETOPT_LONG
static const struct option bb_default_long_options[] = {
/*      { "help", 0, NULL, '?' }, */
	{ 0, 0, 0, 0 }
};

const struct option *applet_long_options = bb_default_long_options;
#endif

uint32_t option_mask32;

uint32_t
getopt32(int argc, char **argv, const char *applet_opts, ...)
{
	unsigned flags = 0;
	unsigned requires = 0;
	t_complementary complementary[33];
	int c;
	const unsigned char *s;
	t_complementary *on_off;
	va_list p;
#if ENABLE_GETOPT_LONG
	const struct option *l_o;
#endif
	unsigned trigger;
	char **pargv = NULL;
	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
#define FREE_FIRST_ARGV_IS_OPT  8
	int spec_flgs = 0;

	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 = *s;
		on_off->switch_on = (1 << c);
		if (*++s == ':') {
			on_off->optarg = va_arg(p, void **);
			while (*++s == ':') /* skip */;
		}
		on_off++;
		c++;
	}

#if ENABLE_GETOPT_LONG
	for (l_o = applet_long_options; l_o->name; l_o++) {
		if (l_o->flag)
			continue;
		for (on_off = complementary; on_off->opt != 0; on_off++)
			if (on_off->opt == l_o->val)
				goto next_long;
		if (c >= 32) break;
		on_off->opt = 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; on_off++)
			if (on_off->opt == *s)
				break;
		if (c == ':' && s[2] == ':') {
			on_off->list_flg++;
			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; on_off++)
					if (on_off->opt == *s) {
						*pair_switch |= on_off->switch_on;
						break;
					}
			}
		}
		s--;
	}
	va_end (p);

	if (spec_flgs & FIRST_ARGV_IS_OPT) {
		if (argv[1] && argv[1][0] != '-' && argv[1][0] != '\0') {
			argv[1] = xasprintf("-%s", argv[1]);
			if (ENABLE_FEATURE_CLEAN_UP)
				spec_flgs |= FREE_FIRST_ARGV_IS_OPT;
		}
	}
	/* Note: just "getopt() <= 0" will not work good 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,
				 applet_long_options, NULL)) != -1) {
#else
	while ((c = getopt(argc, argv, applet_opts)) != -1) {
#endif /* ENABLE_GETOPT_LONG */
		c &= 0xff; /* fight libc's sign extends */
loop_arg_is_opt:
		for (on_off = complementary; on_off->opt != c; on_off++) {
			/* c==0 if long opt have non NULL flag */
			if (on_off->opt == 0 && c != 0)
				bb_show_usage();
		}
		if (flags & on_off->incongruously) {
			if ((spec_flgs & SHOW_USAGE_IF_ERROR))
				bb_show_usage();
			flags |= BB_GETOPT_ERROR;
		}
		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->list_flg) {
			llist_add_to((llist_t **)(on_off->optarg), optarg);
		} else if (on_off->optarg) {
			*(char **)(on_off->optarg) = optarg;
		}
		if (pargv != NULL)
			break;
	}

	if (spec_flgs & ALL_ARGV_IS_OPTS) {
		/* process argv is option, for example "ps" applet */
		if (pargv == NULL)
			pargv = argv + optind;
		while (*pargv) {
			c = **pargv;
			if (c == '\0') {
				pargv++;
			} else {
				(*pargv)++;
				goto loop_arg_is_opt;
			}
		}
	}

#if (ENABLE_AR || ENABLE_TAR) && ENABLE_FEATURE_CLEAN_UP
	if (spec_flgs & FREE_FIRST_ARGV_IS_OPT)
		free(argv[1]);
#endif
	/* check depending requires for given options */
	for (on_off = complementary; on_off->opt; 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	/* 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	#include "libbb.h"
11	#include <getopt.h>
12
13	/* Documentation
14
15	uint32_t
16	getopt32(int argc, char *argv, const char applet_opts, ...)
17
18	The command line options must be declared in const char
19	*applet_opts as a string of chars, for example:
20
21	flags = getopt32(argc, argv, "rnug");
22
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	flags = getopt32(argc, argv, "rnug");
30
31	"r" will add 1 (bit 0)
32	"n" will add 2 (bit 1)
33	"u will add 4 (bit 2)
34	"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	flags = getopt32(argc, 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
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	const struct option *applet_long_options
76
77	This struct allows you to define long options. The syntax for
78	declaring the array is just like that of getopt's longopts.
79	(see getopt(3))
80
81	static const struct option applet_long_options[] = {
82	//name,has_arg,flag,val
83	{ "verbose", 0, 0, 'v' },
84	{ 0, 0, 0, 0 }
85	};
86	applet_long_options = applet_long_options;
87
88	The last member of struct option (val) typically is set to
89	matching short option from applet_opts. If there is no matching
90	char in applet_opts, then:
91	- return bit have next position after short options
92	- if has_arg is not "no_argument", use ptr for arg also
93	- opt_complementary affects it too
94
95	Note: a good applet will make long options configurable via the
96	config process and not a required feature. The current standard
97	is to name the config option CONFIG_FEATURE_<applet>_LONG_OPTIONS.
98
99	const char *opt_complementary
100
101	":" The colon (":") is used to separate groups of two or more chars
102	and/or groups of chars and special characters (stating some
103	conditions to be checked).
104
105	"abc" If groups of two or more chars are specified, the first char
106	is the main option and the other chars are secondary options.
107	Their flags will be turned on if the main option is found even
108	if they are not specifed on the command line. For example:
109
110	opt_complementary = "abc";
111	flags = getopt32(argc, argv, "abcd")
112
113	If getopt() finds "-a" on the command line, then
114	getopt32's return value will be as if "-a -b -c" were
115	found.
116
117	"ww" Adjacent double options have a counter associated which indicates
118	the number of occurences of the option.
119	For example the ps applet needs:
120	if w is given once, GNU ps sets the width to 132,
121	if w is given more than once, it is "unlimited"
122
123	int w_counter = 0;
124	opt_complementary = "ww";
125	getopt32(argc, argv, "w", &w_counter);
126	if (w_counter)
127	width = (w_counter == 1) ? 132 : INT_MAX;
128	else
129	get_terminal_width(...&width...);
130
131	w_counter is a pointer to an integer. It has to be passed to
132	getopt32() after all other option argument sinks.
133
134	For example: accept multiple -v to indicate the level of verbosity
135	and for each -b optarg, add optarg to my_b. Finally, if b is given,
136	turn off c and vice versa:
137
138	llist_t *my_b = NULL;
139	int verbose_level = 0;
140	opt_complementary = "vv:b::b-c:c-b";
141	f = getopt32(argc, argv, "vb:c", &my_b, &verbose_level);
142	if (f & 2) // -c after -b unsets -b flag
143	while (my_b) { dosomething_with(my_b->data); my_b = my_b->link; }
144	if (my_b) // but llist is stored if -b is specified
145	free_llist(my_b);
146	if (verbose_level) printf("verbose level is %d\n", verbose_level);
147
148	Special characters:
149
150	"-" A dash as the first char in a opt_complementary group forces
151	all arguments to be treated as options, even if they have
152	no leading dashes. Next char in this case can't be a digit (0-9),
153	use ':' or end of line. For example:
154
155	opt_complementary = "-:w-x:x-w";
156	getopt32(argc, argv, "wx");
157
158	Allows any arguments to be given without a dash (./program w x)
159	as well as with a dash (./program -x).
160
161	"--" A double dash at the beginning of opt_complementary means the
162	argv[1] string should always be treated as options, even if it isn't
163	prefixed with a "-". This is useful for special syntax in applets
164	such as "ar" and "tar":
165	tar xvf foo.tar
166
167	"-N" A dash as the first char in a opt_complementary group followed
168	by a single digit (0-9) means that at least N non-option
169	arguments must be present on the command line
170
171	"=N" An equal sign as the first char in a opt_complementary group followed
172	by a single digit (0-9) means that exactly N non-option
173	arguments must be present on the command line
174
175	"?N" A "?" as the first char in a opt_complementary group followed
176	by a single digit (0-9) means that at most N arguments must be present
177	on the command line.
178
179	"V-" An option with dash before colon or end-of-line results in
180	bb_show_usage being called if this option is encountered.
181	This is typically used to implement "print verbose usage message
182	and exit" option.
183
184	"-" A dash between two options causes the second of the two
185	to be unset (and ignored) if it is given on the command line.
186
187	[FIXME: what if they are the same? like "x-x"? Is it ever useful?]
188
189	For example:
190	The du applet has the options "-s" and "-d depth". If
191	getopt32 finds -s, then -d is unset or if it finds -d
192	then -s is unset. (Note: busybox implements the GNU
193	"--max-depth" option as "-d".) To obtain this behavior, you
194	set opt_complementary = "s-d:d-s". Only one flag value is
195	added to getopt32's return value depending on the
196	position of the options on the command line. If one of the
197	two options requires an argument pointer (":" in applet_opts
198	as in "d:") optarg is set accordingly.
199
200	char *smax_print_depth;
201
202	opt_complementary = "s-d:d-s:x-x";
203	opt = getopt32(argc, argv, "sd:x", &smax_print_depth);
204
205	if (opt & 2)
206	max_print_depth = atoi(smax_print_depth);
207	if (opt & 4)
208	printf("Detected odd -x usage\n");
209
210	"--" A double dash between two options, or between an option and a group
211	of options, means that they are mutually exclusive. Unlike
212	the "-" case above, an error will be forced if the options
213	are used together.
214
215	For example:
216	The cut applet must have only one type of list specified, so
217	-b, -c and -f are mutally exclusive and should raise an error
218	if specified together. In this case you must set
219	opt_complementary = "b--cf:c--bf:f--bc". If two of the
220	mutually exclusive options are found, getopt32's
221	return value will have the error flag set (BB_GETOPT_ERROR) so
222	that we can check for it:
223
224	if (flags & BB_GETOPT_ERROR)
225	bb_show_usage();
226
227	"x--x" Variation of the above, it means that -x option should occur
228	at most once.
229
230	"?" A "?" as the first char in a opt_complementary group means:
231	if BB_GETOPT_ERROR is detected, don't return, call bb_show_usage
232	and exit instead. Next char after '?' can't be a digit.
233
234	"::" A double colon after a char in opt_complementary means that the
235	option can occur multiple times. Each occurrence will be saved as
236	a llist_t element instead of char*.
237
238	For example:
239	The grep applet can have one or more "-e pattern" arguments.
240	In this case you should use getopt32() as follows:
241
242	llist_t *patterns = NULL;
243
244	(this pointer must be initializated to NULL if the list is empty
245	as required by llist_add_to(llist_t old_head, char *new_item).)
246
247	opt_complementary = "e::";
248
249	getopt32(argc, argv, "e:", &patterns);
250	$ grep -e user -e root /etc/passwd
251	root:x:0:0:root:/root:/bin/bash
252	user:x:500:500::/home/user:/bin/bash
253
254	"?" An "?" between an option and a group of options means that
255	at least one of them is required to occur if the first option
256	occurs in preceding command line arguments.
257
258	For example from "id" applet:
259
260	// Don't allow -n -r -rn -ug -rug -nug -rnug
261	opt_complementary = "r?ug:n?ug:?u--g:g--u";
262	flags = getopt32(argc, argv, "rnug");
263
264	This example allowed only:
265	$ id; id -u; id -g; id -ru; id -nu; id -rg; id -ng; id -rnu; id -rng
266
267	"X" A opt_complementary group with just a single letter means
268	that this option is required. If more than one such group exists,
269	at least one option is required to occur (not all of them).
270	For example from "start-stop-daemon" applet:
271
272	// Don't allow -KS -SK, but -S or -K is required
273	opt_complementary = "K:S:?K--S:S--K";
274	flags = getopt32(argc, argv, "KS...);
275
276
277	Don't forget to use ':'. For example, "?322-22-23X-x-a"
278	is interpreted as "?3:22:-2:2-2:2-3Xa:2--x" -
279	max 3 args; count uses of '-2'; min 2 args; if there is
280	a '-2' option then unset '-3', '-X' and '-a'; if there is
281	a '-2' and after it a '-x' then error out.
282	*/
283
284	/* Code here assumes that 'unsigned' is at least 32 bits wide */
285
286	const char *opt_complementary;
287
288	typedef struct {
289	int opt;
290	int list_flg;
291	unsigned switch_on;
292	unsigned switch_off;
293	unsigned incongruously;
294	unsigned requires;
295	void *optarg; / char optarg or llist_t optarg */
296	int *counter;
297	} t_complementary;
298
299	/* You can set applet_long_options for parse called long options */
300	#if ENABLE_GETOPT_LONG
301	static const struct option bb_default_long_options[] = {
302	/* { "help", 0, NULL, '?' }, */
303	{ 0, 0, 0, 0 }
304	};
305
306	const struct option *applet_long_options = bb_default_long_options;
307	#endif
308
309	uint32_t option_mask32;
310
311	uint32_t
312	getopt32(int argc, char *argv, const char applet_opts, ...)
313	{
314	unsigned flags = 0;
315	unsigned requires = 0;
316	t_complementary complementary[33];
317	int c;
318	const unsigned char *s;
319	t_complementary *on_off;
320	va_list p;
321	#if ENABLE_GETOPT_LONG
322	const struct option *l_o;
323	#endif
324	unsigned trigger;
325	char **pargv = NULL;
326	int min_arg = 0;
327	int max_arg = -1;
328
329	#define SHOW_USAGE_IF_ERROR 1
330	#define ALL_ARGV_IS_OPTS 2
331	#define FIRST_ARGV_IS_OPT 4
332	#define FREE_FIRST_ARGV_IS_OPT 8
333	int spec_flgs = 0;
334
335	va_start(p, applet_opts);
336
337	c = 0;
338	on_off = complementary;
339	memset(on_off, 0, sizeof(complementary));
340
341	/* skip GNU extension */
342	s = (const unsigned char *)applet_opts;
343	if (s == '+' \|\| s == '-')
344	s++;
345	while (*s) {
346	if (c >= 32) break;
347	on_off->opt = *s;
348	on_off->switch_on = (1 << c);
349	if (*++s == ':') {
350	on_off->optarg = va_arg(p, void **);
351	while (++s == ':') / skip */;
352	}
353	on_off++;
354	c++;
355	}
356
357	#if ENABLE_GETOPT_LONG
358	for (l_o = applet_long_options; l_o->name; l_o++) {
359	if (l_o->flag)
360	continue;
361	for (on_off = complementary; on_off->opt != 0; on_off++)
362	if (on_off->opt == l_o->val)
363	goto next_long;
364	if (c >= 32) break;
365	on_off->opt = l_o->val;
366	on_off->switch_on = (1 << c);
367	if (l_o->has_arg != no_argument)
368	on_off->optarg = va_arg(p, void **);
369	c++;
370	next_long: ;
371	}
372	#endif /* ENABLE_GETOPT_LONG */
373	for (s = (const unsigned char )opt_complementary; s && s; s++) {
374	t_complementary *pair;
375	unsigned *pair_switch;
376
377	if (*s == ':')
378	continue;
379	c = s[1];
380	if (*s == '?') {
381	if (c < '0' \|\| c > '9') {
382	spec_flgs \|= SHOW_USAGE_IF_ERROR;
383	} else {
384	max_arg = c - '0';
385	s++;
386	}
387	continue;
388	}
389	if (*s == '-') {
390	if (c < '0' \|\| c > '9') {
391	if (c == '-') {
392	spec_flgs \|= FIRST_ARGV_IS_OPT;
393	s++;
394	} else
395	spec_flgs \|= ALL_ARGV_IS_OPTS;
396	} else {
397	min_arg = c - '0';
398	s++;
399	}
400	continue;
401	}
402	if (*s == '=') {
403	min_arg = max_arg = c - '0';
404	s++;
405	continue;
406	}
407	for (on_off = complementary; on_off->opt; on_off++)
408	if (on_off->opt == *s)
409	break;
410	if (c == ':' && s[2] == ':') {
411	on_off->list_flg++;
412	continue;
413	}
414	if (c == ':' \|\| c == '\0') {
415	requires \|= on_off->switch_on;
416	continue;
417	}
418	if (c == '-' && (s[2] == ':' \|\| s[2] == '\0')) {
419	flags \|= on_off->switch_on;
420	on_off->incongruously \|= on_off->switch_on;
421	s++;
422	continue;
423	}
424	if (c == *s) {
425	on_off->counter = va_arg(p, int *);
426	s++;
427	}
428	pair = on_off;
429	pair_switch = &(pair->switch_on);
430	for (s++; s && s != ':'; s++) {
431	if (*s == '?') {
432	pair_switch = &(pair->requires);
433	} else if (*s == '-') {
434	if (pair_switch == &(pair->switch_off))
435	pair_switch = &(pair->incongruously);
436	else
437	pair_switch = &(pair->switch_off);
438	} else {
439	for (on_off = complementary; on_off->opt; on_off++)
440	if (on_off->opt == *s) {
441	*pair_switch \|= on_off->switch_on;
442	break;
443	}
444	}
445	}
446	s--;
447	}
448	va_end (p);
449
450	if (spec_flgs & FIRST_ARGV_IS_OPT) {
451	if (argv[1] && argv[1][0] != '-' && argv[1][0] != '\0') {
452	argv[1] = xasprintf("-%s", argv[1]);
453	if (ENABLE_FEATURE_CLEAN_UP)
454	spec_flgs \|= FREE_FIRST_ARGV_IS_OPT;
455	}
456	}
457	/* Note: just "getopt() <= 0" will not work good for
458	* "fake" short options, like this one:
459	* wget $'-\203' "Test: test" http://kernel.org/
460	* (supposed to act as --header, but doesn't) */
461	#if ENABLE_GETOPT_LONG
462	while ((c = getopt_long(argc, argv, applet_opts,
463	applet_long_options, NULL)) != -1) {
464	#else
465	while ((c = getopt(argc, argv, applet_opts)) != -1) {
466	#endif /* ENABLE_GETOPT_LONG */
467	c &= 0xff; /* fight libc's sign extends */
468	loop_arg_is_opt:
469	for (on_off = complementary; on_off->opt != c; on_off++) {
470	/* c==0 if long opt have non NULL flag */
471	if (on_off->opt == 0 && c != 0)
472	bb_show_usage();
473	}
474	if (flags & on_off->incongruously) {
475	if ((spec_flgs & SHOW_USAGE_IF_ERROR))
476	bb_show_usage();
477	flags \|= BB_GETOPT_ERROR;
478	}
479	trigger = on_off->switch_on & on_off->switch_off;
480	flags &= ~(on_off->switch_off ^ trigger);
481	flags \|= on_off->switch_on ^ trigger;
482	flags ^= trigger;
483	if (on_off->counter)
484	(*(on_off->counter))++;
485	if (on_off->list_flg) {
486	llist_add_to((llist_t **)(on_off->optarg), optarg);
487	} else if (on_off->optarg) {
488	(char *)(on_off->optarg) = optarg;
489	}
490	if (pargv != NULL)
491	break;
492	}
493
494	if (spec_flgs & ALL_ARGV_IS_OPTS) {
495	/* process argv is option, for example "ps" applet */
496	if (pargv == NULL)
497	pargv = argv + optind;
498	while (*pargv) {
499	c = **pargv;
500	if (c == '\0') {
501	pargv++;
502	} else {
503	(*pargv)++;
504	goto loop_arg_is_opt;
505	}
506	}
507	}
508
509	#if (ENABLE_AR \|\| ENABLE_TAR) && ENABLE_FEATURE_CLEAN_UP
510	if (spec_flgs & FREE_FIRST_ARGV_IS_OPT)
511	free(argv[1]);
512	#endif
513	/* check depending requires for given options */
514	for (on_off = complementary; on_off->opt; on_off++) {
515	if (on_off->requires && (flags & on_off->switch_on) &&
516	(flags & on_off->requires) == 0)
517	bb_show_usage();
518	}
519	if (requires && (flags & requires) == 0)
520	bb_show_usage();
521	argc -= optind;
522	if (argc < min_arg \|\| (max_arg >= 0 && argc > max_arg))
523	bb_show_usage();
524
525	option_mask32 = flags;
526	return flags;
527	}