1 /* args.c - Command line argument parsing. 2 * 3 * Copyright 2006 Rob Landley <rob (at) landley.net> 4 */ 5 6 // NOTE: If option parsing segfaults, switch on TOYBOX_DEBUG in menuconfig. 7 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. 11 12 #include "toys.h" 13 14 // Design goals: 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)" 18 19 /* This uses a getopt-like option string, but not getopt() itself. We call 20 * it the get_opt string. 21 * 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. 25 * 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). 29 * 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. 32 * 33 * Example: 34 * Calling get_optflags() when toys.which->options="ab:c:d" and 35 * argv = ["command", "-b", "fruit", "-d", "walrus"] results in: 36 * 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) 42 * 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) 46 */ 47 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 53 // 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) 67 // (longopt) 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" 73 // 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 81 // 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. 87 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) 93 94 // Linked list of all known options (option string parsed into this). 95 // Hangs off getoptflagstate, freed at end of option parsing. 96 struct opts { 97 struct opts *next; 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" 103 union { 104 long l; 105 FLOAT f; 106 } val[3]; // low, high, default - range of allowed values 107 }; 108 109 // 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). 113 struct longopts { 114 struct longopts *next; 115 struct opts *opt; 116 char *str; 117 int len; 118 }; 119 120 // State during argument parsing. 121 struct getoptflagstate 122 { 123 int argc, minargs, maxargs, nodash; 124 char *arg; 125 struct opts *opts; 126 struct longopts *longopts; 127 int noerror, nodash_now, stopearly; 128 unsigned excludes, requires; 129 }; 130 131 // Use getoptflagstate to parse parse one command line option from argv 132 static int gotflag(struct getoptflagstate *gof, struct opts *opt) 133 { 134 int type; 135 136 // Did we recognize this option? 137 if (!opt) { 138 if (gof->noerror) return 1; 139 help_exit("Unknown option %s", gof->arg); 140 } 141 142 // Might enabling this switch off something else? 143 if (toys.optflags & opt->dex[0]) { 144 struct opts *clr; 145 unsigned long long i = 1; 146 147 // 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]; 151 } 152 153 // Set flags 154 toys.optflags |= opt->dex[1]; 155 gof->excludes |= opt->dex[2]; 156 if (opt->flags&2) gof->stopearly=2; 157 158 if (toys.optflags & gof->excludes) { 159 struct opts *bad; 160 unsigned i = 1; 161 162 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; 165 } 166 help_exit("No '%c' with '%c'", opt->c, bad->c); 167 } 168 169 // Does this option take an argument? 170 if (!gof->arg) { 171 if (opt->flags & 8) return 0; 172 gof->arg = ""; 173 } else gof->arg++; 174 type = opt->type; 175 176 if (type == '@') ++*(opt->arg); 177 else if (type) { 178 char *arg = gof->arg; 179 180 // 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" 183 184 if (gof->nodash_now || (!arg[0] && !(opt->flags & 8))) 185 arg = toys.argv[++gof->argc]; 186 if (!arg) { 187 char *s = "Missing argument to "; 188 struct longopts *lo; 189 190 if (opt->c != -1) help_exit("%s-%c", s, opt->c); 191 192 for (lo = gof->longopts; lo->opt != opt; lo = lo->next); 193 help_exit("%s--%.*s", s, lo->len, lo->str); 194 } 195 196 if (type == ':') *(opt->arg) = (long)arg; 197 else if (type == '*') { 198 struct arg_list **list; 199 200 list = (struct arg_list **)opt->arg; 201 while (*list) list=&((*list)->next); 202 *list = xzalloc(sizeof(struct arg_list)); 203 (*list)->arg = arg; 204 } else if (type == '#' || type == '-') { 205 long l = atolx(arg); 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); 209 210 *(opt->arg) = l; 211 } else if (CFG_TOYBOX_FLOAT && type == '.') { 212 FLOAT *f = (FLOAT *)(opt->arg); 213 214 *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); 219 } 220 221 if (!gof->nodash_now) gof->arg = ""; 222 } 223 224 return 0; 225 } 226 227 // 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) 230 { 231 char *options = toys.which->options; 232 long *nextarg = (long *)&this; 233 struct opts *new = 0; 234 int idx; 235 236 // Parse option format string 237 memset(gof, 0, sizeof(struct getoptflagstate)); 238 gof->maxargs = INT_MAX; 239 if (!options) return; 240 241 // Parse leading special behavior indicators 242 for (;;) { 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++; 248 else break; 249 options++; 250 } 251 252 // Parse option string into a linked list of options with attributes. 253 254 if (!*options) gof->stopearly++; 255 while (*options) { 256 char *temp; 257 258 // Option groups come after all options are defined 259 if (*options == '[') break; 260 261 // Allocate a new list entry when necessary 262 if (!new) { 263 new = xzalloc(sizeof(struct opts)); 264 new->next = gof->opts; 265 gof->opts = new; 266 new->val[0].l = LONG_MIN; 267 new->val[1].l = LONG_MAX; 268 } 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) { 272 char *end; 273 struct longopts *lo; 274 275 // 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"); 278 279 // init a new struct longopts 280 lo = xmalloc(sizeof(struct longopts)); 281 lo->next = gof->longopts; 282 lo->opt = new; 283 lo->str = options; 284 lo->len = end-options; 285 gof->longopts = lo; 286 options = ++end; 287 288 // Mark this struct opt as used, even when no short opt. 289 if (!new->c) new->c = -1; 290 291 continue; 292 293 // If this is the start of a new option that wasn't a longopt, 294 295 } 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; 300 // bounds checking 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 .#"); 309 options = --temp; 310 311 // 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.) 315 } else if (new->c) { 316 new = 0; 317 continue; 318 319 // Claim this option, loop to see what's after it. 320 } else new->c = *options; 321 322 options++; 323 } 324 325 // 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.) 327 idx = 0; 328 for (new = gof->opts; new; new = new->next) { 329 unsigned long long u = 1L<<idx++; 330 331 if (new->c == 1) new->c = 0; 332 new->dex[1] = u; 333 if (new->flags & 1) gof->requires |= u; 334 if (new->type) { 335 new->arg = (void *)nextarg; 336 *(nextarg++) = new->val[2].l; 337 } 338 } 339 340 // Parse trailing group indicators 341 while (*options) { 342 unsigned bits = 0; 343 344 if (CFG_TOYBOX_DEBUG && *options != '[') error_exit("trailing %s", options); 345 346 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 []"); 350 351 // Don't advance past ] but do process it once in loop. 352 while (*options++ != ']') { 353 struct opts *opt; 354 int i; 355 356 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 == ']') { 360 if (!opt) break; 361 if (bits&(1<<i)) opt->dex[idx] |= bits&~(1<<i); 362 } else { 363 if (CFG_TOYBOX_DEBUG && !opt) 364 error_exit("[] unknown target %c", *options); 365 if (opt->c == *options) { 366 bits |= 1<<i; 367 break; 368 } 369 } 370 } 371 } 372 } 373 } 374 375 // Fill out toys.optflags, toys.optargs, and this[] from toys.argv 376 377 void get_optflags(void) 378 { 379 struct getoptflagstate gof; 380 struct opts *catch; 381 unsigned long long saveflags; 382 char *letters[]={"s",""}; 383 384 // Option parsing is a two stage process: parse the option string into 385 // a struct opts list, then use that list to process argv[]; 386 387 // Allocate memory for optargs 388 saveflags = 0; 389 while (toys.argv[saveflags++]); 390 toys.optargs = xzalloc(sizeof(char *)*saveflags); 391 392 parse_optflaglist(&gof); 393 394 // Iterate through command line arguments, skipping argv[0] 395 for (gof.argc=1; toys.argv[gof.argc]; gof.argc++) { 396 gof.arg = toys.argv[gof.argc]; 397 catch = NULL; 398 399 // Parse this argument 400 if (gof.stopearly>1) goto notflag; 401 402 gof.nodash_now = 0; 403 404 // Various things with dashes 405 if (*gof.arg == '-') { 406 407 // Handle - 408 if (!gof.arg[1]) goto notflag; 409 gof.arg++; 410 if (*gof.arg=='-') { 411 struct longopts *lo; 412 413 gof.arg++; 414 // Handle -- 415 if (!*gof.arg) { 416 gof.stopearly += 2; 417 continue; 418 } 419 420 // do we match a known --longopt? 421 for (lo = gof.longopts; lo; lo = lo->next) { 422 if (!strncmp(gof.arg, lo->str, lo->len)) { 423 if (!gof.arg[lo->len]) gof.arg = 0; 424 else if (gof.arg[lo->len] == '=' && lo->opt->type) 425 gof.arg += lo->len; 426 else continue; 427 // It's a match. 428 catch = lo->opt; 429 break; 430 } 431 } 432 433 // Should we handle this --longopt as a non-option argument? 434 if (!lo && gof.noerror) { 435 gof.arg -= 2; 436 goto notflag; 437 } 438 439 // Long option parsed, handle option. 440 gotflag(&gof, catch); 441 continue; 442 } 443 444 // Handle things that don't start with a dash. 445 } else { 446 if (gof.nodash && (gof.nodash>1 || gof.argc == 1)) gof.nodash_now = 1; 447 else goto notflag; 448 } 449 450 // At this point, we have the args part of -args. Loop through 451 // each entry (could be -abc meaning -a -b -c) 452 saveflags = toys.optflags; 453 while (*gof.arg) { 454 455 // Identify next option char. 456 for (catch = gof.opts; catch; catch = catch->next) 457 if (*gof.arg == catch->c) 458 if (!((catch->flags&4) && gof.arg[1])) break; 459 460 // Handle option char (advancing past what was used) 461 if (gotflag(&gof, catch) ) { 462 toys.optflags = saveflags; 463 gof.arg = toys.argv[gof.argc]; 464 goto notflag; 465 } 466 } 467 continue; 468 469 // Not a flag, save value in toys.optargs[] 470 notflag: 471 if (gof.stopearly) gof.stopearly++; 472 toys.optargs[toys.optc++] = toys.argv[gof.argc]; 473 } 474 475 // Sanity check 476 if (toys.optc<gof.minargs) 477 help_exit("Need%s %d argument%s", letters[!!(gof.minargs-1)], 478 gof.minargs, letters[!(gof.minargs-1)]); 479 if (toys.optc>gof.maxargs) 480 help_exit("Max %d argument%s", gof.maxargs, letters[!(gof.maxargs-1)]); 481 if (gof.requires && !(gof.requires & toys.optflags)) { 482 struct opts *req; 483 char needs[32], *s = needs; 484 485 for (req = gof.opts; req; req = req->next) 486 if (req->flags & 1) *(s++) = req->c; 487 *s = 0; 488 489 help_exit("Needs %s-%s", s[1] ? "one of " : "", needs); 490 } 491 492 if (CFG_TOYBOX_FREE) { 493 llist_traverse(gof.opts, free); 494 llist_traverse(gof.longopts, free); 495 } 496 } 497