1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * John B. Roll Jr. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * $xMach: xargs.c,v 1.6 2002/02/23 05:27:47 tim Exp $ 37 */ 38 39 #ifndef lint 40 static const char copyright[] = 41 "@(#) Copyright (c) 1990, 1993\n\ 42 The Regents of the University of California. All rights reserved.\n"; 43 #endif /* not lint */ 44 45 #if 0 46 #ifndef lint 47 static char sccsid[] = "@(#)xargs.c 8.1 (Berkeley) 6/6/93"; 48 #endif /* not lint */ 49 #endif 50 51 #include <sys/cdefs.h> 52 __FBSDID("$FreeBSD$"); 53 54 #include <sys/types.h> 55 #include <sys/wait.h> 56 57 #include <err.h> 58 #include <errno.h> 59 #ifndef BOOTSTRAPPING 60 #include <langinfo.h> 61 #endif 62 #include <locale.h> 63 #include <paths.h> 64 #include <regex.h> 65 #include <stdio.h> 66 #include <stdlib.h> 67 #include <string.h> 68 #include <unistd.h> 69 70 #include "pathnames.h" 71 72 static void parse_input(int, char *[]); 73 static void prerun(int, char *[]); 74 static int prompt(void); 75 static void run(char **); 76 static void usage(void); 77 void strnsubst(char **, const char *, const char *, size_t); 78 79 static char echo[] = _PATH_ECHO; 80 static char **av, **bxp, **ep, **exp, **xp; 81 static char *argp, *bbp, *ebp, *inpline, *p, *replstr; 82 static const char *eofstr; 83 static int count, insingle, indouble, pflag, tflag, Rflag, rval, zflag; 84 static int cnt, Iflag, jfound, Lflag, wasquoted, xflag; 85 86 extern char **environ; 87 88 int 89 main(int argc, char *argv[]) 90 { 91 long arg_max; 92 int ch, Jflag, nargs, nflag, nline; 93 size_t linelen; 94 95 inpline = replstr = NULL; 96 ep = environ; 97 eofstr = ""; 98 Jflag = nflag = 0; 99 100 (void)setlocale(LC_MESSAGES, ""); 101 102 /* 103 * POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that 104 * caused some E2BIG errors, so it was changed to ARG_MAX - 4K. Given 105 * that the smallest argument is 2 bytes in length, this means that 106 * the number of arguments is limited to: 107 * 108 * (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2. 109 * 110 * We arbitrarily limit the number of arguments to 5000. This is 111 * allowed by POSIX.2 as long as the resulting minimum exec line is 112 * at least LINE_MAX. Realloc'ing as necessary is possible, but 113 * probably not worthwhile. 114 */ 115 nargs = 5000; 116 if ((arg_max = sysconf(_SC_ARG_MAX)) == -1) 117 errx(1, "sysconf(_SC_ARG_MAX) failed"); 118 nline = arg_max - 4 * 1024; 119 while (*ep != NULL) { 120 /* 1 byte for each '\0' */ 121 nline -= strlen(*ep++) + 1 + sizeof(*ep); 122 } 123 while ((ch = getopt(argc, argv, "0E:I:J:L:n:pR:s:tx")) != -1) 124 switch(ch) { 125 case 'E': 126 eofstr = optarg; 127 break; 128 case 'I': 129 Jflag = 0; 130 Iflag = 1; 131 Lflag = 1; 132 replstr = optarg; 133 break; 134 case 'J': 135 Iflag = 0; 136 Jflag = 1; 137 replstr = optarg; 138 break; 139 case 'L': 140 Lflag = atoi(optarg); 141 break; 142 case 'n': 143 nflag = 1; 144 if ((nargs = atoi(optarg)) <= 0) 145 errx(1, "illegal argument count"); 146 break; 147 case 'p': 148 pflag = 1; 149 break; 150 case 'R': 151 if ((Rflag = atoi(optarg)) <= 0) 152 errx(1, "illegal number of replacements"); 153 break; 154 case 's': 155 nline = atoi(optarg); 156 break; 157 case 't': 158 tflag = 1; 159 break; 160 case 'x': 161 xflag = 1; 162 break; 163 case '0': 164 zflag = 1; 165 break; 166 case '?': 167 default: 168 usage(); 169 } 170 argc -= optind; 171 argv += optind; 172 173 if (!Iflag && Rflag) 174 usage(); 175 if (Iflag && !Rflag) 176 Rflag = 5; 177 if (xflag && !nflag) 178 usage(); 179 if (Iflag || Lflag) 180 xflag = 1; 181 if (replstr != NULL && *replstr == '\0') 182 errx(1, "replstr may not be empty"); 183 184 /* 185 * Allocate pointers for the utility name, the utility arguments, 186 * the maximum arguments to be read from stdin and the trailing 187 * NULL. 188 */ 189 linelen = 1 + argc + nargs + 1; 190 if ((av = bxp = malloc(linelen * sizeof(char **))) == NULL) 191 errx(1, "malloc failed"); 192 193 /* 194 * Use the user's name for the utility as argv[0], just like the 195 * shell. Echo is the default. Set up pointers for the user's 196 * arguments. 197 */ 198 if (*argv == NULL) 199 cnt = strlen(*bxp++ = echo); 200 else { 201 do { 202 if (Jflag && strcmp(*argv, replstr) == 0) { 203 char **avj; 204 jfound = 1; 205 argv++; 206 for (avj = argv; *avj; avj++) 207 cnt += strlen(*avj) + 1; 208 break; 209 } 210 cnt += strlen(*bxp++ = *argv) + 1; 211 } while (*++argv != NULL); 212 } 213 214 /* 215 * Set up begin/end/traversing pointers into the array. The -n 216 * count doesn't include the trailing NULL pointer, so the malloc 217 * added in an extra slot. 218 */ 219 exp = (xp = bxp) + nargs; 220 221 /* 222 * Allocate buffer space for the arguments read from stdin and the 223 * trailing NULL. Buffer space is defined as the default or specified 224 * space, minus the length of the utility name and arguments. Set up 225 * begin/end/traversing pointers into the array. The -s count does 226 * include the trailing NULL, so the malloc didn't add in an extra 227 * slot. 228 */ 229 nline -= cnt; 230 if (nline <= 0) 231 errx(1, "insufficient space for command"); 232 233 if ((bbp = malloc((size_t)(nline + 1))) == NULL) 234 errx(1, "malloc failed"); 235 ebp = (argp = p = bbp) + nline - 1; 236 for (;;) 237 parse_input(argc, argv); 238 } 239 240 static void 241 parse_input(int argc, char *argv[]) 242 { 243 int ch, foundeof; 244 char **avj; 245 246 foundeof = 0; 247 248 switch(ch = getchar()) { 249 case EOF: 250 /* No arguments since last exec. */ 251 if (p == bbp) 252 exit(rval); 253 goto arg1; 254 case ' ': 255 case '\t': 256 /* Quotes escape tabs and spaces. */ 257 if (insingle || indouble || zflag) 258 goto addch; 259 goto arg2; 260 case '\0': 261 if (zflag) 262 goto arg2; 263 goto addch; 264 case '\n': 265 count++; 266 if (zflag) 267 goto addch; 268 269 /* Quotes do not escape newlines. */ 270 arg1: if (insingle || indouble) 271 errx(1, "unterminated quote"); 272 arg2: 273 foundeof = *eofstr != '\0' && 274 strcmp(argp, eofstr) == 0; 275 276 /* Do not make empty args unless they are quoted */ 277 if ((argp != p || wasquoted) && !foundeof) { 278 *p++ = '\0'; 279 *xp++ = argp; 280 if (Iflag) { 281 size_t curlen; 282 283 if (inpline == NULL) 284 curlen = 0; 285 else { 286 /* 287 * If this string is not zero 288 * length, append a space for 289 * seperation before the next 290 * argument. 291 */ 292 if ((curlen = strlen(inpline))) 293 strcat(inpline, " "); 294 } 295 curlen++; 296 /* 297 * Allocate enough to hold what we will 298 * be holding in a second, and to append 299 * a space next time through, if we have 300 * to. 301 */ 302 inpline = realloc(inpline, curlen + 2 + 303 strlen(argp)); 304 if (inpline == NULL) 305 errx(1, "realloc failed"); 306 if (curlen == 1) 307 strcpy(inpline, argp); 308 else 309 strcat(inpline, argp); 310 } 311 } 312 313 /* 314 * If max'd out on args or buffer, or reached EOF, 315 * run the command. If xflag and max'd out on buffer 316 * but not on args, object. Having reached the limit 317 * of input lines, as specified by -L is the same as 318 * maxing out on arguments. 319 */ 320 if (xp == exp || p > ebp || ch == EOF || 321 (Lflag <= count && xflag) || foundeof) { 322 if (xflag && xp != exp && p > ebp) 323 errx(1, "insufficient space for arguments"); 324 if (jfound) { 325 for (avj = argv; *avj; avj++) 326 *xp++ = *avj; 327 } 328 prerun(argc, av); 329 if (ch == EOF || foundeof) 330 exit(rval); 331 p = bbp; 332 xp = bxp; 333 count = 0; 334 } 335 argp = p; 336 wasquoted = 0; 337 break; 338 case '\'': 339 if (indouble || zflag) 340 goto addch; 341 insingle = !insingle; 342 wasquoted = 1; 343 break; 344 case '"': 345 if (insingle || zflag) 346 goto addch; 347 indouble = !indouble; 348 wasquoted = 1; 349 break; 350 case '\\': 351 if (zflag) 352 goto addch; 353 /* Backslash escapes anything, is escaped by quotes. */ 354 if (!insingle && !indouble && (ch = getchar()) == EOF) 355 errx(1, "backslash at EOF"); 356 /* FALLTHROUGH */ 357 default: 358 addch: if (p < ebp) { 359 *p++ = ch; 360 break; 361 } 362 363 /* If only one argument, not enough buffer space. */ 364 if (bxp == xp) 365 errx(1, "insufficient space for argument"); 366 /* Didn't hit argument limit, so if xflag object. */ 367 if (xflag) 368 errx(1, "insufficient space for arguments"); 369 370 if (jfound) { 371 for (avj = argv; *avj; avj++) 372 *xp++ = *avj; 373 } 374 prerun(argc, av); 375 xp = bxp; 376 cnt = ebp - argp; 377 memcpy(bbp, argp, (size_t)cnt); 378 p = (argp = bbp) + cnt; 379 *p++ = ch; 380 break; 381 } 382 return; 383 } 384 385 /* 386 * Do things necessary before run()'ing, such as -I substitution, 387 * and then call run(). 388 */ 389 static void 390 prerun(int argc, char *argv[]) 391 { 392 char **tmp, **tmp2, **avj; 393 int repls; 394 395 repls = Rflag; 396 397 if (argc == 0 || repls == 0) { 398 *xp = NULL; 399 run(argv); 400 return; 401 } 402 403 avj = argv; 404 405 /* 406 * Allocate memory to hold the argument list, and 407 * a NULL at the tail. 408 */ 409 tmp = malloc((argc + 1) * sizeof(char**)); 410 if (tmp == NULL) 411 errx(1, "malloc failed"); 412 tmp2 = tmp; 413 414 /* 415 * Save the first argument and iterate over it, we 416 * cannot do strnsubst() to it. 417 */ 418 if ((*tmp++ = strdup(*avj++)) == NULL) 419 errx(1, "strdup failed"); 420 421 /* 422 * For each argument to utility, if we have not used up 423 * the number of replacements we are allowed to do, and 424 * if the argument contains at least one occurance of 425 * replstr, call strnsubst(), else just save the string. 426 * Iterations over elements of avj and tmp are done 427 * where appropriate. 428 */ 429 while (--argc) { 430 *tmp = *avj++; 431 if (repls && strstr(*tmp, replstr) != NULL) { 432 strnsubst(tmp++, replstr, inpline, (size_t)255); 433 repls--; 434 } else { 435 if ((*tmp = strdup(*tmp)) == NULL) 436 errx(1, "strdup failed"); 437 tmp++; 438 } 439 } 440 441 /* 442 * Run it. 443 */ 444 *tmp = NULL; 445 run(tmp2); 446 447 /* 448 * Walk from the tail to the head, free along the way. 449 */ 450 for (; tmp2 != tmp; tmp--) 451 free(*tmp); 452 /* 453 * Now free the list itself. 454 */ 455 free(tmp2); 456 457 /* 458 * Free the input line buffer, if we have one. 459 */ 460 if (inpline != NULL) { 461 free(inpline); 462 inpline = NULL; 463 } 464 } 465 466 static void 467 run(char **argv) 468 { 469 volatile int childerr; 470 char **avec; 471 pid_t pid; 472 int status; 473 474 /* 475 * If the user wants to be notified of each command before it is 476 * executed, notify them. If they want the notification to be 477 * followed by a prompt, then prompt them. 478 */ 479 if (tflag || pflag) { 480 (void)fprintf(stderr, "%s", *argv); 481 for (avec = argv + 1; *avec != NULL; ++avec) 482 (void)fprintf(stderr, " %s", *avec); 483 /* 484 * If the user has asked to be prompted, do so. 485 */ 486 if (pflag) 487 /* 488 * If they asked not to exec, return without execution 489 * but if they asked to, go to the execution. If we 490 * could not open their tty, break the switch and drop 491 * back to -t behaviour. 492 */ 493 switch (prompt()) { 494 case 0: 495 return; 496 case 1: 497 goto exec; 498 case 2: 499 break; 500 } 501 (void)fprintf(stderr, "\n"); 502 (void)fflush(stderr); 503 } 504 exec: 505 childerr = 0; 506 switch(pid = vfork()) { 507 case -1: 508 err(1, "vfork"); 509 case 0: 510 execvp(argv[0], argv); 511 childerr = errno; 512 _exit(1); 513 } 514 pid = waitpid(pid, &status, 0); 515 if (pid == -1) 516 err(1, "waitpid"); 517 /* If we couldn't invoke the utility, exit. */ 518 if (childerr != 0) 519 err(childerr == ENOENT ? 127 : 126, "%s", *argv); 520 /* If utility signaled or exited with a value of 255, exit 1-125. */ 521 if (WIFSIGNALED(status) || WEXITSTATUS(status) == 255) 522 exit(1); 523 if (WEXITSTATUS(status)) 524 rval = 1; 525 } 526 527 /* 528 * Prompt the user about running a command. 529 */ 530 static int 531 prompt(void) 532 { 533 regex_t cre; 534 size_t rsize; 535 int match; 536 char *response; 537 FILE *ttyfp; 538 539 if ((ttyfp = fopen(_PATH_TTY, "r")) == NULL) 540 return (2); /* Indicate that the TTY failed to open. */ 541 (void)fprintf(stderr, "?..."); 542 (void)fflush(stderr); 543 if ((response = fgetln(ttyfp, &rsize)) == NULL || 544 regcomp(&cre, 545 #ifdef BOOTSTRAPPING 546 "^[yY]", 547 #else 548 nl_langinfo(YESEXPR), 549 #endif 550 REG_BASIC) != 0) { 551 (void)fclose(ttyfp); 552 return (0); 553 } 554 match = regexec(&cre, response, 0, NULL, 0); 555 (void)fclose(ttyfp); 556 regfree(&cre); 557 return (match == 0); 558 } 559 560 static void 561 usage(void) 562 { 563 fprintf(stderr, 564 "usage: xargs [-0pt] [-E eofstr] [-I replstr [-R replacements]] [-J replstr]\n" 565 " [-L number] [-n number [-x] [-s size] [utility [argument ...]]\n"); 566 exit(1); 567 } 568