1 /* args.c - Command line argument parsing.
3 * Copyright 2006 Rob Landley <rob@landley.net>
6 // NOTE: If option parsing segfaults, switch on TOYBOX_DEBUG in menuconfig.
8 // Enabling TOYBOX_DEBUG in .config adds syntax checks to option string parsing
9 // which aren't needed in the final code (your option string is hardwired and
10 // should be correct when you ship), but are useful for development.
15 // Don't use getopt() out of libc.
16 // Don't permute original arguments (screwing up ps/top output).
17 // Integrated --long options "(noshort)a(along)b(blong1)(blong2)"
19 /* This uses a getopt-like option string, but not getopt() itself. We call
20 * it the get_opt string.
22 * Each option in the get_opt string corresponds to a bit position in the
23 * return value. The rightmost argument is (1<<0), the next to last is (1<<1)
24 * and so on. If the option isn't seen in argv[], its bit remains 0.
26 * Options which have an argument fill in the corresponding slot in the global
27 * union "this" (see generated/globals.h), which it treats as an array of longs
28 * (note that sizeof(long)==sizeof(pointer) is guaranteed by LP64).
30 * You don't have to free the option strings, which point into the environment
31 * space. List objects should be freed by main() when command_main() returns.
34 * Calling get_optflags() when toys.which->options="ab:c:d" and
35 * argv = ["command", "-b", "fruit", "-d", "walrus"] results in:
37 * Changes to struct toys:
38 * toys.optflags = 5 (I.E. 0101 so -b = 4 | -d = 1)
39 * toys.optargs[0] = "walrus" (leftover argument)
40 * toys.optargs[1] = NULL (end of list)
41 * toys.optc = 1 (there was 1 leftover argument)
43 * Changes to union this:
44 * this[0]=NULL (because -c didn't get an argument this time)
45 * this[1]="fruit" (argument to -b)
48 // What you can put in a get_opt string:
49 // Any otherwise unused character (all letters, unprefixed numbers) specify
50 // an option that sets a flag. The bit value is the same as the binary digit
51 // if you string the option characters together in order.
52 // So in "abcdefgh" a = 128, h = 1
54 // Suffixes specify that this option takes an argument (stored in GLOBALS):
55 // Note that pointer and long are always the same size, even on 64 bit.
56 // : plus a string argument, keep most recent if more than one
57 // * plus a string argument, appended to a list
58 // # plus a signed long argument
59 // <LOW - die if less than LOW
60 // >HIGH - die if greater than HIGH
61 // =DEFAULT - value if not specified
62 // - plus a signed long argument defaulting to negative (say + for positive)
63 // . plus a double precision floating point argument (with CFG_TOYBOX_FLOAT)
64 // Chop this option out with USE_TOYBOX_FLOAT() in option string
65 // Same <LOW>HIGH=DEFAULT as #
66 // @ plus an occurrence counter (which is a long)
68 // | this is required. If more than one marked, only one required.
69 // ; long option's argument is optional (can only be supplied with --opt=)
70 // ^ Stop parsing after encountering this argument
71 // " " (space char) the "plus an argument" must be separate
72 // I.E. "-j 3" not "-j3". So "kill -stop" != "kill -s top"
74 // At the beginning of the get_opt string (before any options):
75 // ^ stop at first nonoption argument
76 // <0 die if less than # leftover arguments (default 0)
77 // >9 die if > # leftover arguments (default MAX_INT)
78 // ? Allow unknown arguments (pass them through to command).
79 // & first argument has imaginary dash (ala tar/ps)
80 // If given twice, all arguments have imaginary dash
82 // At the end: [groups] of previously seen options
83 // - Only one in group (switch off) [-abc] means -ab=-b, -ba=-a, -abc=-c
84 // + Synonyms (switch on all) [+abc] means -ab=-abc, -c=-abc
85 // ! More than one in group is error [!abc] means -ab calls error_exit()
86 // primarily useful if you can switch things back off again.
88 // Notes from getopt man page
89 // - and -- cannot be arguments.
90 // -- force end of arguments
91 // - is a synonym for stdin in file arguments
92 // -abcd means -a -b -c -d (but if -b takes an argument, then it's -a -b cd)
94 // Linked list of all known options (option string parsed into this).
95 // Hangs off getoptflagstate, freed at end of option parsing.
98 long *arg; // Pointer into union "this" to store arguments at.
99 int c; // Argument character to match
100 int flags; // |=1, ^=2, " "=4, ;=8
101 unsigned long long dex[3]; // bits to disable/enable/exclude in toys.optflags
102 char type; // Type of arguments to store union "this"
106 } val[3]; // low, high, default - range of allowed values
109 // linked list of long options. (Hangs off getoptflagstate, free at end of
110 // option parsing, details about flag to set and global slot to fill out
111 // stored in related short option struct, but if opt->c = -1 the long option
112 // is "bare" (has no corresponding short option).
114 struct longopts *next;
120 // State during argument parsing.
121 struct getoptflagstate
123 int argc, minargs, maxargs, nodash;
126 struct longopts *longopts;
127 int noerror, nodash_now, stopearly;
128 unsigned excludes, requires;
131 // Use getoptflagstate to parse parse one command line option from argv
132 static int gotflag(struct getoptflagstate *gof, struct opts *opt)
136 // Did we recognize this option?
138 if (gof->noerror) return 1;
139 help_exit("Unknown option %s", gof->arg);
142 // Might enabling this switch off something else?
143 if (toys.optflags & opt->dex[0]) {
145 unsigned long long i = 1;
147 // Forget saved argument for flag we switch back off
148 for (clr=gof->opts, i=1; clr; clr = clr->next, i<<=1)
149 if (clr->arg && (i & toys.optflags & opt->dex[0])) *clr->arg = 0;
150 toys.optflags &= ~opt->dex[0];
154 toys.optflags |= opt->dex[1];
155 gof->excludes |= opt->dex[2];
156 if (opt->flags&2) gof->stopearly=2;
158 if (toys.optflags & gof->excludes) {
162 for (bad=gof->opts, i=1; ;bad = bad->next, i<<=1) {
163 if (opt == bad || !(i & toys.optflags)) continue;
164 if (toys.optflags & bad->dex[2]) break;
166 help_exit("No '%c' with '%c'", opt->c, bad->c);
169 // Does this option take an argument?
171 if (opt->flags & 8) return 0;
176 if (type == '@') ++*(opt->arg);
178 char *arg = gof->arg;
180 // Handle "-xblah" and "-x blah", but also a third case: "abxc blah"
181 // to make "tar xCjfv blah1 blah2 thingy" work like
182 // "tar -x -C blah1 -j -f blah2 -v thingy"
184 if (gof->nodash_now || (!arg[0] && !(opt->flags & 8)))
185 arg = toys.argv[++gof->argc];
187 char *s = "Missing argument to ";
190 if (opt->c != -1) help_exit("%s-%c", s, opt->c);
192 for (lo = gof->longopts; lo->opt != opt; lo = lo->next);
193 help_exit("%s--%.*s", s, lo->len, lo->str);
196 if (type == ':') *(opt->arg) = (long)arg;
197 else if (type == '*') {
198 struct arg_list **list;
200 list = (struct arg_list **)opt->arg;
201 while (*list) list=&((*list)->next);
202 *list = xzalloc(sizeof(struct arg_list));
204 } else if (type == '#' || type == '-') {
206 if (type == '-' && !ispunct(*arg)) l*=-1;
207 if (l < opt->val[0].l) help_exit("-%c < %ld", opt->c, opt->val[0].l);
208 if (l > opt->val[1].l) help_exit("-%c > %ld", opt->c, opt->val[1].l);
211 } else if (CFG_TOYBOX_FLOAT && type == '.') {
212 FLOAT *f = (FLOAT *)(opt->arg);
214 *f = strtod(arg, &arg);
215 if (opt->val[0].l != LONG_MIN && *f < opt->val[0].f)
216 help_exit("-%c < %lf", opt->c, (double)opt->val[0].f);
217 if (opt->val[1].l != LONG_MAX && *f > opt->val[1].f)
218 help_exit("-%c > %lf", opt->c, (double)opt->val[1].f);
221 if (!gof->nodash_now) gof->arg = "";
227 // Parse this command's options string into struct getoptflagstate, which
228 // includes a struct opts linked list in reverse order (I.E. right-to-left)
229 void parse_optflaglist(struct getoptflagstate *gof)
231 char *options = toys.which->options;
232 long *nextarg = (long *)&this;
233 struct opts *new = 0;
236 // Parse option format string
237 memset(gof, 0, sizeof(struct getoptflagstate));
238 gof->maxargs = INT_MAX;
239 if (!options) return;
241 // Parse leading special behavior indicators
243 if (*options == '^') gof->stopearly++;
244 else if (*options == '<') gof->minargs=*(++options)-'0';
245 else if (*options == '>') gof->maxargs=*(++options)-'0';
246 else if (*options == '?') gof->noerror++;
247 else if (*options == '&') gof->nodash++;
252 // Parse option string into a linked list of options with attributes.
254 if (!*options) gof->stopearly++;
258 // Option groups come after all options are defined
259 if (*options == '[') break;
261 // Allocate a new list entry when necessary
263 new = xzalloc(sizeof(struct opts));
264 new->next = gof->opts;
266 new->val[0].l = LONG_MIN;
267 new->val[1].l = LONG_MAX;
269 // Each option must start with "(" or an option character. (Bare
270 // longopts only come at the start of the string.)
271 if (*options == '(' && new->c != -1) {
275 // Find the end of the longopt
276 for (end = ++options; *end && *end != ')'; end++);
277 if (CFG_TOYBOX_DEBUG && !*end) error_exit("(longopt) didn't end");
279 // init a new struct longopts
280 lo = xmalloc(sizeof(struct longopts));
281 lo->next = gof->longopts;
284 lo->len = end-options;
288 // Mark this struct opt as used, even when no short opt.
289 if (!new->c) new->c = -1;
293 // If this is the start of a new option that wasn't a longopt,
295 } else if (strchr(":*#@.-", *options)) {
296 if (CFG_TOYBOX_DEBUG && new->type)
297 error_exit("multiple types %c:%c%c", new->c, new->type, *options);
298 new->type = *options;
299 } else if (-1 != (idx = stridx("|^ ;", *options))) new->flags |= 1<<idx;
301 else if (-1 != (idx = stridx("<>=", *options))) {
302 if (new->type == '#') {
303 long l = strtol(++options, &temp, 10);
304 if (temp != options) new->val[idx].l = l;
305 } else if (CFG_TOYBOX_FLOAT && new->type == '.') {
306 FLOAT f = strtod(++options, &temp);
307 if (temp != options) new->val[idx].f = f;
308 } else if (CFG_TOYBOX_DEBUG) error_exit("<>= only after .#");
311 // At this point, we've hit the end of the previous option. The
312 // current character is the start of a new option. If we've already
313 // assigned an option to this struct, loop to allocate a new one.
314 // (It'll get back here afterwards and fall through to next else.)
319 // Claim this option, loop to see what's after it.
320 } else new->c = *options;
325 // Initialize enable/disable/exclude masks and pointers to store arguments.
326 // (This goes right to left so we need the whole list before we can start.)
328 for (new = gof->opts; new; new = new->next) {
329 unsigned long long u = 1L<<idx++;
331 if (new->c == 1) new->c = 0;
333 if (new->flags & 1) gof->requires |= u;
335 new->arg = (void *)nextarg;
336 *(nextarg++) = new->val[2].l;
340 // Parse trailing group indicators
344 if (CFG_TOYBOX_DEBUG && *options != '[') error_exit("trailing %s", options);
346 idx = stridx("-+!", *++options);
347 if (CFG_TOYBOX_DEBUG && idx == -1) error_exit("[ needs +-!");
348 if (CFG_TOYBOX_DEBUG && (options[1] == ']' || !options[1]))
349 error_exit("empty []");
351 // Don't advance past ] but do process it once in loop.
352 while (*options++ != ']') {
356 if (CFG_TOYBOX_DEBUG && !*options) error_exit("[ without ]");
357 // Find this option flag (in previously parsed struct opt)
358 for (i=0, opt = gof->opts; ; i++, opt = opt->next) {
359 if (*options == ']') {
361 if (bits&(1<<i)) opt->dex[idx] |= bits&~(1<<i);
363 if (*options==1) break;
364 if (CFG_TOYBOX_DEBUG && !opt)
365 error_exit("[] unknown target %c", *options);
366 if (opt->c == *options) {
376 // Fill out toys.optflags, toys.optargs, and this[] from toys.argv
378 void get_optflags(void)
380 struct getoptflagstate gof;
382 unsigned long long saveflags;
383 char *letters[]={"s",""};
385 // Option parsing is a two stage process: parse the option string into
386 // a struct opts list, then use that list to process argv[];
388 // Allocate memory for optargs
390 while (toys.argv[saveflags++]);
391 toys.optargs = xzalloc(sizeof(char *)*saveflags);
393 parse_optflaglist(&gof);
395 // Iterate through command line arguments, skipping argv[0]
396 for (gof.argc=1; toys.argv[gof.argc]; gof.argc++) {
397 gof.arg = toys.argv[gof.argc];
400 // Parse this argument
401 if (gof.stopearly>1) goto notflag;
405 // Various things with dashes
406 if (*gof.arg == '-') {
409 if (!gof.arg[1]) goto notflag;
421 // do we match a known --longopt?
422 for (lo = gof.longopts; lo; lo = lo->next) {
423 if (!strncmp(gof.arg, lo->str, lo->len)) {
424 if (!gof.arg[lo->len]) gof.arg = 0;
425 else if (gof.arg[lo->len] == '=' && lo->opt->type)
434 // Should we handle this --longopt as a non-option argument?
435 if (!lo && gof.noerror) {
440 // Long option parsed, handle option.
441 gotflag(&gof, catch);
445 // Handle things that don't start with a dash.
447 if (gof.nodash && (gof.nodash>1 || gof.argc == 1)) gof.nodash_now = 1;
451 // At this point, we have the args part of -args. Loop through
452 // each entry (could be -abc meaning -a -b -c)
453 saveflags = toys.optflags;
456 // Identify next option char.
457 for (catch = gof.opts; catch; catch = catch->next)
458 if (*gof.arg == catch->c)
459 if (!((catch->flags&4) && gof.arg[1])) break;
461 // Handle option char (advancing past what was used)
462 if (gotflag(&gof, catch) ) {
463 toys.optflags = saveflags;
464 gof.arg = toys.argv[gof.argc];
470 // Not a flag, save value in toys.optargs[]
472 if (gof.stopearly) gof.stopearly++;
473 toys.optargs[toys.optc++] = toys.argv[gof.argc];
477 if (toys.optc<gof.minargs)
478 help_exit("Need%s %d argument%s", letters[!!(gof.minargs-1)],
479 gof.minargs, letters[!(gof.minargs-1)]);
480 if (toys.optc>gof.maxargs)
481 help_exit("Max %d argument%s", gof.maxargs, letters[!(gof.maxargs-1)]);
482 if (gof.requires && !(gof.requires & toys.optflags)) {
484 char needs[32], *s = needs;
486 for (req = gof.opts; req; req = req->next)
487 if (req->flags & 1) *(s++) = req->c;
490 help_exit("Needs %s-%s", s[1] ? "one of " : "", needs);
493 if (CFG_TOYBOX_FREE) {
494 llist_traverse(gof.opts, free);
495 llist_traverse(gof.longopts, free);