path: root/libbb/getopt32.c (plain)
blob: 15b6efc096ba0ef04f409bcd27f37a6bfece232c

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 source tree.
8	*/
9
10	#if ENABLE_LONG_OPTS || ENABLE_FEATURE_GETOPT_LONG
11	# include <getopt.h>
12	#endif
13	#include "libbb.h"
14
15	/* Documentation
16
17	uint32_t
18	getopt32(char **argv, const char *applet_opts, ...)
19
20	The command line options are passed as the applet_opts string.
21
22	If one of the given options is found, a flag value is added to
23	the return value.
24
25	The flag value is determined by the position of the char in
26	applet_opts string. For example:
27
28	flags = getopt32(argv, "rnug");
29
30	"r" will set 1 (bit 0)
31	"n" will set 2 (bit 1)
32	"u" will set 4 (bit 2)
33	"g" will set 8 (bit 3)
34
35	and so on. You can also look at the return value as a bit
36	field and each option sets one bit.
37
38	On exit, global variable optind is set so that if you
39	will do argc -= optind; argv += optind; then
40	argc will be equal to number of remaining non-option
41	arguments, first one would be in argv[0], next in argv[1] and so on
42	(options and their parameters will be moved into argv[]
43	positions prior to argv[optind]).
44
45	"o:" If one of the options requires an argument, then add a ":"
46	after the char in applet_opts and provide a pointer to store
47	the argument. For example:
48
49	char *pointer_to_arg_for_a;
50	char *pointer_to_arg_for_b;
51	char *pointer_to_arg_for_c;
52	char *pointer_to_arg_for_d;
53
54	flags = getopt32(argv, "a:b:c:d:",
55	&pointer_to_arg_for_a, &pointer_to_arg_for_b,
56	&pointer_to_arg_for_c, &pointer_to_arg_for_d);
57
58	The type of the pointer may be controlled by "o::" or "o+" in
59	the external string opt_complementary (see below for more info).
60
61	"o::" If option can have an *optional* argument, then add a "::"
62	after its char in applet_opts and provide a pointer to store
63	the argument. Note that optional arguments _must_
64	immediately follow the option: -oparam, not -o param.
65
66	"o:+" This means that the parameter for this option is a nonnegative integer.
67	It will be processed with xatoi_positive() - allowed range
68	is 0..INT_MAX.
69
70	int param; // "unsigned param;" will also work
71	getopt32(argv, "p:+", &param);
72
73	"o:*" This means that the option can occur multiple times. Each occurrence
74	will be saved as a llist_t element instead of char*.
75
76	For example:
77	The grep applet can have one or more "-e pattern" arguments.
78	In this case you should use getopt32() as follows:
79
80	llist_t *patterns = NULL;
81
82	(this pointer must be initializated to NULL if the list is empty
83	as required by llist_add_to_end(llist_t **old_head, char *new_item).)
84
85	getopt32(argv, "e:*", &patterns);
86
87	$ grep -e user -e root /etc/passwd
88	root:x:0:0:root:/root:/bin/bash
89	user:x:500:500::/home/user:/bin/bash
90
91	"+" If the first character in the applet_opts string is a plus,
92	then option processing will stop as soon as a non-option is
93	encountered in the argv array. Useful for applets like env
94	which should not process arguments to subprograms:
95	env -i ls -d /
96	Here we want env to process just the '-i', not the '-d'.
97
98	"!" Report bad option, missing required options,
99	inconsistent options with all-ones return value (instead of abort).
100
101	const char *applet_long_options
102
103	This struct allows you to define long options:
104
105	static const char applet_longopts[] ALIGN1 =
106	//"name\0" has_arg val
107	"verbose\0" No_argument "v"
108	;
109	applet_long_options = applet_longopts;
110
111	The last member of struct option (val) typically is set to
112	matching short option from applet_opts. If there is no matching
113	char in applet_opts, then:
114	- return bit has next position after short options
115	- if has_arg is not "No_argument", use ptr for arg also
116	- opt_complementary affects it too
117
118	Note: a good applet will make long options configurable via the
119	config process and not a required feature. The current standard
120	is to name the config option CONFIG_FEATURE_<applet>_LONG_OPTIONS.
121
122	const char *opt_complementary
123
124	":" The colon (":") is used to separate groups of two or more chars
125	and/or groups of chars and special characters (stating some
126	conditions to be checked).
127
128	"abc" If groups of two or more chars are specified, the first char
129	is the main option and the other chars are secondary options.
130	Their flags will be turned on if the main option is found even
131	if they are not specifed on the command line. For example:
132
133	opt_complementary = "abc";
134	flags = getopt32(argv, "abcd")
135
136	If getopt() finds "-a" on the command line, then
137	getopt32's return value will be as if "-a -b -c" were
138	found.
139
140	"ww" Adjacent double options have a counter associated which indicates
141	the number of occurrences of the option.
142	For example the ps applet needs:
143	if w is given once, GNU ps sets the width to 132,
144	if w is given more than once, it is "unlimited"
145
146	int w_counter = 0; // must be initialized!
147	opt_complementary = "ww";
148	getopt32(argv, "w", &w_counter);
149	if (w_counter)
150	width = (w_counter == 1) ? 132 : INT_MAX;
151	else
152	get_terminal_width(...&width...);
153
154	w_counter is a pointer to an integer. It has to be passed to
155	getopt32() after all other option argument sinks.
156
157	For example: accept multiple -v to indicate the level of verbosity
158	and for each -b optarg, add optarg to my_b. Finally, if b is given,
159	turn off c and vice versa:
160
161	llist_t *my_b = NULL;
162	int verbose_level = 0;
163	opt_complementary = "vv:b-c:c-b";
164	f = getopt32(argv, "vb:*c", &my_b, &verbose_level);
165	if (f & 2) // -c after -b unsets -b flag
166	while (my_b) dosomething_with(llist_pop(&my_b));
167	if (my_b) // but llist is stored if -b is specified
168	free_llist(my_b);
169	if (verbose_level) printf("verbose level is %d\n", verbose_level);
170
171	Special characters:
172
173	"-" A group consisting of just a dash forces all arguments
174	to be treated as options, even if they have no leading dashes.
175	Next char in this case can't be a digit (0-9), use ':' or end of line.
176	Example:
177
178	opt_complementary = "-:w-x:x-w"; // "-w-x:x-w" would also work,
179	getopt32(argv, "wx"); // but is less readable
180
181	This makes it possible to use options without a dash (./program w x)
182	as well as with a dash (./program -x).
183
184	NB: getopt32() will leak a small amount of memory if you use
185	this option! Do not use it if there is a possibility of recursive
186	getopt32() calls.
187
188	"--" A double dash at the beginning of opt_complementary means the
189	argv[1] string should always be treated as options, even if it isn't
190	prefixed with a "-". This is useful for special syntax in applets
191	such as "ar" and "tar":
192	tar xvf foo.tar
193
194	NB: getopt32() will leak a small amount of memory if you use
195	this option! Do not use it if there is a possibility of recursive
196	getopt32() calls.
197
198	"-N" A dash as the first char in a opt_complementary group followed
199	by a single digit (0-9) means that at least N non-option
200	arguments must be present on the command line
201
202	"=N" An equal sign as the first char in a opt_complementary group followed
203	by a single digit (0-9) means that exactly N non-option
204	arguments must be present on the command line
205
206	"?N" A "?" as the first char in a opt_complementary group followed
207	by a single digit (0-9) means that at most N arguments must be present
208	on the command line.
209
210	"V-" An option with dash before colon or end-of-line results in
211	bb_show_usage() being called if this option is encountered.
212	This is typically used to implement "print verbose usage message
213	and exit" option.
214
215	"a-b" A dash between two options causes the second of the two
216	to be unset (and ignored) if it is given on the command line.
217
218	[FIXME: what if they are the same? like "x-x"? Is it ever useful?]
219
220	For example:
221	The du applet has the options "-s" and "-d depth". If
222	getopt32 finds -s, then -d is unset or if it finds -d
223	then -s is unset. (Note: busybox implements the GNU
224	"--max-depth" option as "-d".) To obtain this behavior, you
225	set opt_complementary = "s-d:d-s". Only one flag value is
226	added to getopt32's return value depending on the
227	position of the options on the command line. If one of the
228	two options requires an argument pointer (":" in applet_opts
229	as in "d:") optarg is set accordingly.
230
231	char *smax_print_depth;
232
233	opt_complementary = "s-d:d-s:x-x";
234	opt = getopt32(argv, "sd:x", &smax_print_depth);
235
236	if (opt & 2)
237	max_print_depth = atoi(smax_print_depth);
238	if (opt & 4)
239	printf("Detected odd -x usage\n");
240
241	"a--b" A double dash between two options, or between an option and a group
242	of options, means that they are mutually exclusive. Unlike
243	the "-" case above, an error will be forced if the options
244	are used together.
245
246	For example:
247	The cut applet must have only one type of list specified, so
248	-b, -c and -f are mutually exclusive and should raise an error
249	if specified together. In this case you must set
250	opt_complementary = "b--cf:c--bf:f--bc". If two of the
251	mutually exclusive options are found, getopt32 will call
252	bb_show_usage() and die.
253
254	"x--x" Variation of the above, it means that -x option should occur
255	at most once.
256
257	"o+" A plus after a char in opt_complementary means that the parameter
258	for this option is a nonnegative integer. It will be processed
259	with xatoi_positive() - allowed range is 0..INT_MAX.
260
261	int param; // "unsigned param;" will also work
262	opt_complementary = "p+";
263	getopt32(argv, "p:", &param);
264
265	"o::" A double colon after a char in opt_complementary means that the
266	option can occur multiple times. Each occurrence will be saved as
267	a llist_t element instead of char*.
268
269	For example:
270	The grep applet can have one or more "-e pattern" arguments.
271	In this case you should use getopt32() as follows:
272
273	llist_t *patterns = NULL;
274
275	(this pointer must be initializated to NULL if the list is empty
276	as required by llist_add_to_end(llist_t **old_head, char *new_item).)
277
278	opt_complementary = "e::";
279	getopt32(argv, "e:", &patterns);
280
281	$ grep -e user -e root /etc/passwd
282	root:x:0:0:root:/root:/bin/bash
283	user:x:500:500::/home/user:/bin/bash
284
285	"o+" and "o::" can be handled by "o:+" and "o:*" specifiers
286	in option string (and it is preferred), but this does not work
287	for "long options only" cases, such as tar --exclude=PATTERN,
288	wget --header=HDR cases.
289
290	"a?b" A "?" between an option and a group of options means that
291	at least one of them is required to occur if the first option
292	occurs in preceding command line arguments.
293
294	For example from "id" applet:
295
296	// Don't allow -n -r -rn -ug -rug -nug -rnug
297	opt_complementary = "r?ug:n?ug:u--g:g--u";
298	flags = getopt32(argv, "rnug");
299
300	This example allowed only:
301	$ id; id -u; id -g; id -ru; id -nu; id -rg; id -ng; id -rnu; id -rng
302
303	"X" A opt_complementary group with just a single letter means
304	that this option is required. If more than one such group exists,
305	at least one option is required to occur (not all of them).
306	For example from "start-stop-daemon" applet:
307
308	// Don't allow -KS -SK, but -S or -K is required
309	opt_complementary = "K:S:K--S:S--K";
310	flags = getopt32(argv, "KS...);
311
312
313	Don't forget to use ':'. For example, "?322-22-23X-x-a"
314	is interpreted as "?3:22:-2:2-2:2-3Xa:2--x" -
315	max 3 args; count uses of '-2'; min 2 args; if there is
316	a '-2' option then unset '-3', '-X' and '-a'; if there is
317	a '-2' and after it a '-x' then error out.
318	But it's far too obfuscated. Use ':' to separate groups.
319	*/
320
321	/* Code here assumes that 'unsigned' is at least 32 bits wide */
322
323	const char *const bb_argv_dash[] = { "-", NULL };
324
325	const char *opt_complementary;
326
327	enum {
328	PARAM_STRING,
329	PARAM_LIST,
330	PARAM_INT,
331	};
332
333	typedef struct {
334	unsigned char opt_char;
335	smallint param_type;
336	unsigned switch_on;
337	unsigned switch_off;
338	unsigned incongruously;
339	unsigned requires;
340	void **optarg; /* char**, llist_t** or int *. */
341	int *counter;
342	} t_complementary;
343
344	/* You can set applet_long_options for parse called long options */
345	#if ENABLE_LONG_OPTS || ENABLE_FEATURE_GETOPT_LONG
346	static const struct option bb_null_long_options[1] = {
347	{ 0, 0, 0, 0 }
348	};
349	const char *applet_long_options;
350	#endif
351
352	uint32_t option_mask32;
353
354	uint32_t FAST_FUNC
355	getopt32(char **argv, const char *applet_opts, ...)
356	{
357	int argc;
358	unsigned flags = 0;
359	unsigned requires = 0;
360	t_complementary complementary[33]; /* last stays zero-filled */
361	char first_char;
362	int c;
363	const unsigned char *s;
364	t_complementary *on_off;
365	va_list p;
366	#if ENABLE_LONG_OPTS || ENABLE_FEATURE_GETOPT_LONG
367	const struct option *l_o;
368	struct option *long_options = (struct option *) &bb_null_long_options;
369	#endif
370	unsigned trigger;
371	char **pargv;
372	int min_arg = 0;
373	int max_arg = -1;
374
375	#define SHOW_USAGE_IF_ERROR 1
376	#define ALL_ARGV_IS_OPTS 2
377	#define FIRST_ARGV_IS_OPT 4
378
379	int spec_flgs = 0;
380
381	/* skip 0: some applets cheat: they do not actually HAVE argv[0] */
382	argc = 1;
383	while (argv[argc])
384	argc++;
385
386	va_start(p, applet_opts);
387
388	on_off = complementary;
389	memset(on_off, 0, sizeof(complementary));
390
391	applet_opts = strcpy(alloca(strlen(applet_opts) + 1), applet_opts);
392
393	/* skip bbox extension */
394	first_char = applet_opts[0];
395	if (first_char == '!')
396	applet_opts++;
397
398	/* skip GNU extension */
399	s = (const unsigned char *)applet_opts;
400	if (*s == '+' || *s == '-')
401	s++;
402	c = 0;
403	while (*s) {
404	if (c >= 32)
405	break;
406	on_off->opt_char = *s;
407	on_off->switch_on = (1 << c);
408	if (*++s == ':') {
409	on_off->optarg = va_arg(p, void **);
410	if (s[1] == '+' || s[1] == '*') {
411	/* 'o:+' or 'o:*' */
412	on_off->param_type = (s[1] == '+') ?
413	PARAM_INT : PARAM_LIST;
414	overlapping_strcpy((char*)s + 1, (char*)s + 2);
415	}
416	/* skip possible 'o::' (or 'o:+:' !) */
417	while (*++s == ':')
418	continue;
419	}
420	on_off++;
421	c++;
422	}
423
424	#if ENABLE_LONG_OPTS || ENABLE_FEATURE_GETOPT_LONG
425	if (applet_long_options) {
426	const char *optstr;
427	unsigned i, count;
428
429	count = 1;
430	optstr = applet_long_options;
431	while (optstr[0]) {
432	optstr += strlen(optstr) + 3; /* skip NUL, has_arg, val */
433	count++;
434	}
435	/* count == no. of longopts + 1 */
436	long_options = alloca(count * sizeof(*long_options));
437	memset(long_options, 0, count * sizeof(*long_options));
438	i = 0;
439	optstr = applet_long_options;
440	while (--count) {
441	long_options[i].name = optstr;
442	optstr += strlen(optstr) + 1;
443	long_options[i].has_arg = (unsigned char)(*optstr++);
444	/* long_options[i].flag = NULL; */
445	long_options[i].val = (unsigned char)(*optstr++);
446	i++;
447	}
448	for (l_o = long_options; l_o->name; l_o++) {
449	if (l_o->flag)
450	continue;
451	for (on_off = complementary; on_off->opt_char; on_off++)
452	if (on_off->opt_char == l_o->val)
453	goto next_long;
454	if (c >= 32)
455	break;
456	on_off->opt_char = l_o->val;
457	on_off->switch_on = (1 << c);
458	if (l_o->has_arg != no_argument)
459	on_off->optarg = va_arg(p, void **);
460	c++;
461	next_long: ;
462	}
463	/* Make it unnecessary to clear applet_long_options
464	* by hand after each call to getopt32
465	*/
466	applet_long_options = NULL;
467	}
468	#endif /* ENABLE_LONG_OPTS || ENABLE_FEATURE_GETOPT_LONG */
469
470	for (s = (const unsigned char *)opt_complementary; s && *s; s++) {
471	t_complementary *pair;
472	unsigned *pair_switch;
473
474	if (*s == ':')
475	continue;
476	c = s[1];
477	if (*s == '?') {
478	if (c < '0' || c > '9') {
479	spec_flgs |= SHOW_USAGE_IF_ERROR;
480	} else {
481	max_arg = c - '0';
482	s++;
483	}
484	continue;
485	}
486	if (*s == '-') {
487	if (c < '0' || c > '9') {
488	if (c == '-') {
489	spec_flgs |= FIRST_ARGV_IS_OPT;
490	s++;
491	} else
492	spec_flgs |= ALL_ARGV_IS_OPTS;
493	} else {
494	min_arg = c - '0';
495	s++;
496	}
497	continue;
498	}
499	if (*s == '=') {
500	min_arg = max_arg = c - '0';
501	s++;
502	continue;
503	}
504	for (on_off = complementary; on_off->opt_char; on_off++)
505	if (on_off->opt_char == *s)
506	goto found_opt;
507	/* Without this, diagnostic of such bugs is not easy */
508	bb_error_msg_and_die("NO OPT %c!", *s);
509	found_opt:
510	if (c == ':' && s[2] == ':') {
511	on_off->param_type = PARAM_LIST;
512	continue;
513	}
514	if (c == '+' && (s[2] == ':' || s[2] == '\0')) {
515	on_off->param_type = PARAM_INT;
516	s++;
517	continue;
518	}
519	if (c == ':' || c == '\0') {
520	requires |= on_off->switch_on;
521	continue;
522	}
523	if (c == '-' && (s[2] == ':' || s[2] == '\0')) {
524	flags |= on_off->switch_on;
525	on_off->incongruously |= on_off->switch_on;
526	s++;
527	continue;
528	}
529	if (c == *s) {
530	on_off->counter = va_arg(p, int *);
531	s++;
532	}
533	pair = on_off;
534	pair_switch = &pair->switch_on;
535	for (s++; *s && *s != ':'; s++) {
536	if (*s == '?') {
537	pair_switch = &pair->requires;
538	} else if (*s == '-') {
539	if (pair_switch == &pair->switch_off)
540	pair_switch = &pair->incongruously;
541	else
542	pair_switch = &pair->switch_off;
543	} else {
544	for (on_off = complementary; on_off->opt_char; on_off++)
545	if (on_off->opt_char == *s) {
546	*pair_switch |= on_off->switch_on;
547	break;
548	}
549	}
550	}
551	s--;
552	}
553	opt_complementary = NULL;
554	va_end(p);
555
556	if (spec_flgs & (FIRST_ARGV_IS_OPT | ALL_ARGV_IS_OPTS)) {
557	pargv = argv + 1;
558	while (*pargv) {
559	if (pargv[0][0] != '-' && pargv[0][0] != '\0') {
560	/* Can't use alloca: opts with params will
561	* return pointers to stack!
562	* NB: we leak these allocations... */
563	char *pp = xmalloc(strlen(*pargv) + 2);
564	*pp = '-';
565	strcpy(pp + 1, *pargv);
566	*pargv = pp;
567	}
568	if (!(spec_flgs & ALL_ARGV_IS_OPTS))
569	break;
570	pargv++;
571	}
572	}
573
574	/* In case getopt32 was already called:
575	* reset the libc getopt() function, which keeps internal state.
576	* run_nofork_applet() does this, but we might end up here
577	* also via gunzip_main() -> gzip_main(). Play safe.
578	*/
579	#ifdef __GLIBC__
580	optind = 0;
581	#else /* BSD style */
582	optind = 1;
583	/* optreset = 1; */
584	#endif
585	/* optarg = NULL; opterr = 0; optopt = 0; - do we need this?? */
586
587	/* Note: just "getopt() <= 0" will not work well for
588	* "fake" short options, like this one:
589	* wget $'-\203' "Test: test" http://kernel.org/
590	* (supposed to act as --header, but doesn't) */
591	#if ENABLE_LONG_OPTS || ENABLE_FEATURE_GETOPT_LONG
592	while ((c = getopt_long(argc, argv, applet_opts,
593	long_options, NULL)) != -1) {
594	#else
595	while ((c = getopt(argc, argv, applet_opts)) != -1) {
596	#endif
597	/* getopt prints "option requires an argument -- X"
598	* and returns '?' if an option has no arg, but one is reqd */
599	c &= 0xff; /* fight libc's sign extension */
600	for (on_off = complementary; on_off->opt_char != c; on_off++) {
601	/* c can be NUL if long opt has non-NULL ->flag,
602	* but we construct long opts so that flag
603	* is always NULL (see above) */
604	if (on_off->opt_char == '\0' /* && c != '\0' */) {
605	/* c is probably '?' - "bad option" */
606	goto error;
607	}
608	}
609	if (flags & on_off->incongruously)
610	goto error;
611	trigger = on_off->switch_on & on_off->switch_off;
612	flags &= ~(on_off->switch_off ^ trigger);
613	flags |= on_off->switch_on ^ trigger;
614	flags ^= trigger;
615	if (on_off->counter)
616	(*(on_off->counter))++;
617	if (optarg) {
618	if (on_off->param_type == PARAM_LIST) {
619	llist_add_to_end((llist_t **)(on_off->optarg), optarg);
620	} else if (on_off->param_type == PARAM_INT) {
621	//TODO: xatoi_positive indirectly pulls in printf machinery
622	*(unsigned*)(on_off->optarg) = xatoi_positive(optarg);
623	} else if (on_off->optarg) {
624	*(char **)(on_off->optarg) = optarg;
625	}
626	}
627	}
628
629	/* check depending requires for given options */
630	for (on_off = complementary; on_off->opt_char; on_off++) {
631	if (on_off->requires
632	&& (flags & on_off->switch_on)
633	&& (flags & on_off->requires) == 0
634	) {
635	goto error;
636	}
637	}
638	if (requires && (flags & requires) == 0)
639	goto error;
640	argc -= optind;
641	if (argc < min_arg || (max_arg >= 0 && argc > max_arg))
642	goto error;
643
644	option_mask32 = flags;
645	return flags;
646
647	error:
648	if (first_char != '!')
649	bb_show_usage();
650	return (int32_t)-1;
651	}
652