1/* Create and destroy argument vectors (argv's) 2 Copyright (C) 1992-2022 Free Software Foundation, Inc. 3 Written by Fred Fish @ Cygnus Support 4 5This file is part of the libiberty library. 6Libiberty is free software; you can redistribute it and/or 7modify it under the terms of the GNU Library General Public 8License as published by the Free Software Foundation; either 9version 2 of the License, or (at your option) any later version. 10 11Libiberty is distributed in the hope that it will be useful, 12but WITHOUT ANY WARRANTY; without even the implied warranty of 13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14Library General Public License for more details. 15 16You should have received a copy of the GNU Library General Public 17License along with libiberty; see the file COPYING.LIB. If 18not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, 19Boston, MA 02110-1301, USA. */ 20 21 22/* Create and destroy argument vectors. An argument vector is simply an 23 array of string pointers, terminated by a NULL pointer. */ 24 25#ifdef HAVE_CONFIG_H 26#include "config.h" 27#endif 28#include "ansidecl.h" 29#include "libiberty.h" 30#include "safe-ctype.h" 31 32/* Routines imported from standard C runtime libraries. */ 33 34#include <stddef.h> 35#include <string.h> 36#include <stdlib.h> 37#include <stdio.h> 38#include <sys/types.h> 39#ifdef HAVE_UNISTD_H 40#include <unistd.h> 41#endif 42#if HAVE_SYS_STAT_H 43#include <sys/stat.h> 44#endif 45 46#ifndef NULL 47#define NULL 0 48#endif 49 50#ifndef EOS 51#define EOS '\0' 52#endif 53 54#define INITIAL_MAXARGC 8 /* Number of args + NULL in initial argv */ 55 56 57/* 58 59@deftypefn Extension char** dupargv (char * const *@var{vector}) 60 61Duplicate an argument vector. Simply scans through @var{vector}, 62duplicating each argument until the terminating @code{NULL} is found. 63Returns a pointer to the argument vector if successful. Returns 64@code{NULL} if there is insufficient memory to complete building the 65argument vector. 66 67@end deftypefn 68 69*/ 70 71char ** 72dupargv (char * const *argv) 73{ 74 int argc; 75 char **copy; 76 77 if (argv == NULL) 78 return NULL; 79 80 /* the vector */ 81 for (argc = 0; argv[argc] != NULL; argc++); 82 copy = (char **) xmalloc ((argc + 1) * sizeof (char *)); 83 84 /* the strings */ 85 for (argc = 0; argv[argc] != NULL; argc++) 86 copy[argc] = xstrdup (argv[argc]); 87 copy[argc] = NULL; 88 return copy; 89} 90 91/* 92 93@deftypefn Extension void freeargv (char **@var{vector}) 94 95Free an argument vector that was built using @code{buildargv}. Simply 96scans through @var{vector}, freeing the memory for each argument until 97the terminating @code{NULL} is found, and then frees @var{vector} 98itself. 99 100@end deftypefn 101 102*/ 103 104void freeargv (char **vector) 105{ 106 register char **scan; 107 108 if (vector != NULL) 109 { 110 for (scan = vector; *scan != NULL; scan++) 111 { 112 free (*scan); 113 } 114 free (vector); 115 } 116} 117 118static void 119consume_whitespace (const char **input) 120{ 121 while (ISSPACE (**input)) 122 { 123 (*input)++; 124 } 125} 126 127static int 128only_whitespace (const char* input) 129{ 130 while (*input != EOS && ISSPACE (*input)) 131 input++; 132 133 return (*input == EOS); 134} 135 136/* 137 138@deftypefn Extension char** buildargv (char *@var{sp}) 139 140Given a pointer to a string, parse the string extracting fields 141separated by whitespace and optionally enclosed within either single 142or double quotes (which are stripped off), and build a vector of 143pointers to copies of the string for each field. The input string 144remains unchanged. The last element of the vector is followed by a 145@code{NULL} element. 146 147All of the memory for the pointer array and copies of the string 148is obtained from @code{xmalloc}. All of the memory can be returned to the 149system with the single function call @code{freeargv}, which takes the 150returned result of @code{buildargv}, as it's argument. 151 152Returns a pointer to the argument vector if successful. Returns 153@code{NULL} if @var{sp} is @code{NULL} or if there is insufficient 154memory to complete building the argument vector. 155 156If the input is a null string (as opposed to a @code{NULL} pointer), 157then buildarg returns an argument vector that has one arg, a null 158string. 159 160@end deftypefn 161 162The memory for the argv array is dynamically expanded as necessary. 163 164In order to provide a working buffer for extracting arguments into, 165with appropriate stripping of quotes and translation of backslash 166sequences, we allocate a working buffer at least as long as the input 167string. This ensures that we always have enough space in which to 168work, since the extracted arg is never larger than the input string. 169 170The argument vector is always kept terminated with a @code{NULL} arg 171pointer, so it can be passed to @code{freeargv} at any time, or 172returned, as appropriate. 173 174*/ 175 176char **buildargv (const char *input) 177{ 178 char *arg; 179 char *copybuf; 180 int squote = 0; 181 int dquote = 0; 182 int bsquote = 0; 183 int argc = 0; 184 int maxargc = 0; 185 char **argv = NULL; 186 char **nargv; 187 188 if (input != NULL) 189 { 190 copybuf = (char *) xmalloc (strlen (input) + 1); 191 /* Is a do{}while to always execute the loop once. Always return an 192 argv, even for null strings. See NOTES above, test case below. */ 193 do 194 { 195 /* Pick off argv[argc] */ 196 consume_whitespace (&input); 197 198 if ((maxargc == 0) || (argc >= (maxargc - 1))) 199 { 200 /* argv needs initialization, or expansion */ 201 if (argv == NULL) 202 { 203 maxargc = INITIAL_MAXARGC; 204 nargv = (char **) xmalloc (maxargc * sizeof (char *)); 205 } 206 else 207 { 208 maxargc *= 2; 209 nargv = (char **) xrealloc (argv, maxargc * sizeof (char *)); 210 } 211 argv = nargv; 212 argv[argc] = NULL; 213 } 214 /* Begin scanning arg */ 215 arg = copybuf; 216 while (*input != EOS) 217 { 218 if (ISSPACE (*input) && !squote && !dquote && !bsquote) 219 { 220 break; 221 } 222 else 223 { 224 if (bsquote) 225 { 226 bsquote = 0; 227 *arg++ = *input; 228 } 229 else if (*input == '\\') 230 { 231 bsquote = 1; 232 } 233 else if (squote) 234 { 235 if (*input == '\'') 236 { 237 squote = 0; 238 } 239 else 240 { 241 *arg++ = *input; 242 } 243 } 244 else if (dquote) 245 { 246 if (*input == '"') 247 { 248 dquote = 0; 249 } 250 else 251 { 252 *arg++ = *input; 253 } 254 } 255 else 256 { 257 if (*input == '\'') 258 { 259 squote = 1; 260 } 261 else if (*input == '"') 262 { 263 dquote = 1; 264 } 265 else 266 { 267 *arg++ = *input; 268 } 269 } 270 input++; 271 } 272 } 273 *arg = EOS; 274 argv[argc] = xstrdup (copybuf); 275 argc++; 276 argv[argc] = NULL; 277 278 consume_whitespace (&input); 279 } 280 while (*input != EOS); 281 282 free (copybuf); 283 } 284 return (argv); 285} 286 287/* 288 289@deftypefn Extension int writeargv (char * const *@var{argv}, FILE *@var{file}) 290 291Write each member of ARGV, handling all necessary quoting, to the file 292named by FILE, separated by whitespace. Return 0 on success, non-zero 293if an error occurred while writing to FILE. 294 295@end deftypefn 296 297*/ 298 299int 300writeargv (char * const *argv, FILE *f) 301{ 302 int status = 0; 303 304 if (f == NULL) 305 return 1; 306 307 while (*argv != NULL) 308 { 309 const char *arg = *argv; 310 311 while (*arg != EOS) 312 { 313 char c = *arg; 314 315 if (ISSPACE(c) || c == '\\' || c == '\'' || c == '"') 316 if (EOF == fputc ('\\', f)) 317 { 318 status = 1; 319 goto done; 320 } 321 322 if (EOF == fputc (c, f)) 323 { 324 status = 1; 325 goto done; 326 } 327 arg++; 328 } 329 330 /* Write out a pair of quotes for an empty argument. */ 331 if (arg == *argv) 332 if (EOF == fputs ("\"\"", f)) 333 { 334 status = 1; 335 goto done; 336 } 337 338 if (EOF == fputc ('\n', f)) 339 { 340 status = 1; 341 goto done; 342 } 343 argv++; 344 } 345 346 done: 347 return status; 348} 349 350/* 351 352@deftypefn Extension void expandargv (int *@var{argcp}, char ***@var{argvp}) 353 354The @var{argcp} and @code{argvp} arguments are pointers to the usual 355@code{argc} and @code{argv} arguments to @code{main}. This function 356looks for arguments that begin with the character @samp{@@}. Any such 357arguments are interpreted as ``response files''. The contents of the 358response file are interpreted as additional command line options. In 359particular, the file is separated into whitespace-separated strings; 360each such string is taken as a command-line option. The new options 361are inserted in place of the option naming the response file, and 362@code{*argcp} and @code{*argvp} will be updated. If the value of 363@code{*argvp} is modified by this function, then the new value has 364been dynamically allocated and can be deallocated by the caller with 365@code{freeargv}. However, most callers will simply call 366@code{expandargv} near the beginning of @code{main} and allow the 367operating system to free the memory when the program exits. 368 369@end deftypefn 370 371*/ 372 373void 374expandargv (int *argcp, char ***argvp) 375{ 376 /* The argument we are currently processing. */ 377 int i = 0; 378 /* To check if ***argvp has been dynamically allocated. */ 379 char ** const original_argv = *argvp; 380 /* Limit the number of response files that we parse in order 381 to prevent infinite recursion. */ 382 unsigned int iteration_limit = 2000; 383 /* Loop over the arguments, handling response files. We always skip 384 ARGVP[0], as that is the name of the program being run. */ 385 while (++i < *argcp) 386 { 387 /* The name of the response file. */ 388 const char *filename; 389 /* The response file. */ 390 FILE *f; 391 /* An upper bound on the number of characters in the response 392 file. */ 393 long pos; 394 /* The number of characters in the response file, when actually 395 read. */ 396 size_t len; 397 /* A dynamically allocated buffer used to hold options read from a 398 response file. */ 399 char *buffer; 400 /* Dynamically allocated storage for the options read from the 401 response file. */ 402 char **file_argv; 403 /* The number of options read from the response file, if any. */ 404 size_t file_argc; 405#ifdef S_ISDIR 406 struct stat sb; 407#endif 408 /* We are only interested in options of the form "@file". */ 409 filename = (*argvp)[i]; 410 if (filename[0] != '@') 411 continue; 412 /* If we have iterated too many times then stop. */ 413 if (-- iteration_limit == 0) 414 { 415 fprintf (stderr, "%s: error: too many @-files encountered\n", (*argvp)[0]); 416 xexit (1); 417 } 418#ifdef S_ISDIR 419 if (stat (filename+1, &sb) < 0) 420 continue; 421 if (S_ISDIR(sb.st_mode)) 422 { 423 fprintf (stderr, "%s: error: @-file refers to a directory\n", (*argvp)[0]); 424 xexit (1); 425 } 426#endif 427 /* Read the contents of the file. */ 428 f = fopen (++filename, "r"); 429 if (!f) 430 continue; 431 if (fseek (f, 0L, SEEK_END) == -1) 432 goto error; 433 pos = ftell (f); 434 if (pos == -1) 435 goto error; 436 if (fseek (f, 0L, SEEK_SET) == -1) 437 goto error; 438 buffer = (char *) xmalloc (pos * sizeof (char) + 1); 439 len = fread (buffer, sizeof (char), pos, f); 440 if (len != (size_t) pos 441 /* On Windows, fread may return a value smaller than POS, 442 due to CR/LF->CR translation when reading text files. 443 That does not in-and-of itself indicate failure. */ 444 && ferror (f)) 445 { 446 free (buffer); 447 goto error; 448 } 449 /* Add a NUL terminator. */ 450 buffer[len] = '\0'; 451 /* If the file is empty or contains only whitespace, buildargv would 452 return a single empty argument. In this context we want no arguments, 453 instead. */ 454 if (only_whitespace (buffer)) 455 { 456 file_argv = (char **) xmalloc (sizeof (char *)); 457 file_argv[0] = NULL; 458 } 459 else 460 /* Parse the string. */ 461 file_argv = buildargv (buffer); 462 /* If *ARGVP is not already dynamically allocated, copy it. */ 463 if (*argvp == original_argv) 464 *argvp = dupargv (*argvp); 465 /* Count the number of arguments. */ 466 file_argc = 0; 467 while (file_argv[file_argc]) 468 ++file_argc; 469 /* Free the original option's memory. */ 470 free ((*argvp)[i]); 471 /* Now, insert FILE_ARGV into ARGV. The "+1" below handles the 472 NULL terminator at the end of ARGV. */ 473 *argvp = ((char **) 474 xrealloc (*argvp, 475 (*argcp + file_argc + 1) * sizeof (char *))); 476 memmove (*argvp + i + file_argc, *argvp + i + 1, 477 (*argcp - i) * sizeof (char *)); 478 memcpy (*argvp + i, file_argv, file_argc * sizeof (char *)); 479 /* The original option has been replaced by all the new 480 options. */ 481 *argcp += file_argc - 1; 482 /* Free up memory allocated to process the response file. We do 483 not use freeargv because the individual options in FILE_ARGV 484 are now in the main ARGV. */ 485 free (file_argv); 486 free (buffer); 487 /* Rescan all of the arguments just read to support response 488 files that include other response files. */ 489 --i; 490 error: 491 /* We're all done with the file now. */ 492 fclose (f); 493 } 494} 495 496/* 497 498@deftypefn Extension int countargv (char * const *@var{argv}) 499 500Return the number of elements in @var{argv}. 501Returns zero if @var{argv} is NULL. 502 503@end deftypefn 504 505*/ 506 507int 508countargv (char * const *argv) 509{ 510 int argc; 511 512 if (argv == NULL) 513 return 0; 514 for (argc = 0; argv[argc] != NULL; argc++) 515 continue; 516 return argc; 517} 518 519#ifdef MAIN 520 521/* Simple little test driver. */ 522 523static const char *const tests[] = 524{ 525 "a simple command line", 526 "arg 'foo' is single quoted", 527 "arg \"bar\" is double quoted", 528 "arg \"foo bar\" has embedded whitespace", 529 "arg 'Jack said \\'hi\\'' has single quotes", 530 "arg 'Jack said \\\"hi\\\"' has double quotes", 531 "a b c d e f g h i j k l m n o p q r s t u v w x y z 1 2 3 4 5 6 7 8 9", 532 533 /* This should be expanded into only one argument. */ 534 "trailing-whitespace ", 535 536 "", 537 NULL 538}; 539 540int 541main (void) 542{ 543 char **argv; 544 const char *const *test; 545 char **targs; 546 547 for (test = tests; *test != NULL; test++) 548 { 549 printf ("buildargv(\"%s\")\n", *test); 550 if ((argv = buildargv (*test)) == NULL) 551 { 552 printf ("failed!\n\n"); 553 } 554 else 555 { 556 for (targs = argv; *targs != NULL; targs++) 557 { 558 printf ("\t\"%s\"\n", *targs); 559 } 560 printf ("\n"); 561 } 562 freeargv (argv); 563 } 564 565 return 0; 566} 567 568#endif /* MAIN */ 569