1 /* $NetBSD: xargs.c,v 1.14 2003/08/07 11:17:49 agc Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * John B. Roll Jr. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #ifndef lint 37 __COPYRIGHT("@(#) Copyright (c) 1990, 1993\n\ 38 The Regents of the University of California. All rights reserved.\n"); 39 #endif /* not lint */ 40 41 #ifndef lint 42 #if 0 43 static char sccsid[] = "@(#)xargs.c 8.1 (Berkeley) 6/6/93"; 44 #endif 45 __RCSID("$NetBSD: xargs.c,v 1.14 2003/08/07 11:17:49 agc Exp $"); 46 #endif /* not lint */ 47 48 #include <sys/types.h> 49 #include <sys/wait.h> 50 #include <err.h> 51 #include <errno.h> 52 #include <langinfo.h> 53 #include <limits.h> 54 #include <locale.h> 55 #include <paths.h> 56 #include <regex.h> 57 #include <signal.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 #include "pathnames.h" 63 64 static int pflag, tflag, zflag, rval; 65 static FILE *promptfile; 66 static regex_t yesexpr; 67 68 static void run __P((char **)); 69 int main __P((int, char **)); 70 static void usage __P((void)); 71 72 int 73 main(argc, argv) 74 int argc; 75 char **argv; 76 { 77 int ch; 78 char *p, *bbp, *ebp, **bxp, **exp, **xp; 79 int cnt, indouble, insingle, nargs, nflag, nline, xflag; 80 char **av, *argp; 81 82 setlocale(LC_ALL, ""); 83 84 /* 85 * POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that 86 * caused some E2BIG errors, so it was changed to ARG_MAX - 4K. Given 87 * that the smallest argument is 2 bytes in length, this means that 88 * the number of arguments is limited to: 89 * 90 * (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2. 91 * 92 * We arbitrarily limit the number of arguments to 5000. This is 93 * allowed by POSIX.2 as long as the resulting minimum exec line is 94 * at least LINE_MAX. Realloc'ing as necessary is possible, but 95 * probably not worthwhile. 96 */ 97 nargs = 5000; 98 nline = ARG_MAX - 4 * 1024; 99 nflag = xflag = 0; 100 while ((ch = getopt(argc, argv, "0n:ps:tx")) != -1) 101 switch(ch) { 102 case '0': 103 zflag = 1; 104 break; 105 case 'n': 106 nflag = 1; 107 if ((nargs = atoi(optarg)) <= 0) 108 errx(1, "illegal argument count"); 109 break; 110 case 'p': 111 pflag = tflag = 1; 112 break; 113 case 's': 114 nline = atoi(optarg); 115 break; 116 case 't': 117 tflag = 1; 118 break; 119 case 'x': 120 xflag = 1; 121 break; 122 case '?': 123 default: 124 usage(); 125 } 126 argc -= optind; 127 argv += optind; 128 129 if (xflag && !nflag) 130 usage(); 131 132 /* 133 * Allocate pointers for the utility name, the utility arguments, 134 * the maximum arguments to be read from stdin and the trailing 135 * NULL. 136 */ 137 if (!(av = bxp = 138 malloc((u_int)(1 + argc + nargs + 1) * sizeof(char **)))) 139 err(1, "malloc"); 140 141 /* 142 * Use the user's name for the utility as argv[0], just like the 143 * shell. Echo is the default. Set up pointers for the user's 144 * arguments. 145 */ 146 if (!*argv) 147 cnt = strlen(*bxp++ = _PATH_ECHO); 148 else { 149 cnt = 0; 150 do { 151 cnt += strlen(*bxp++ = *argv) + 1; 152 } while (*++argv); 153 } 154 155 /* 156 * Set up begin/end/traversing pointers into the array. The -n 157 * count doesn't include the trailing NULL pointer, so the malloc 158 * added in an extra slot. 159 */ 160 exp = (xp = bxp) + nargs; 161 162 /* 163 * Allocate buffer space for the arguments read from stdin and the 164 * trailing NULL. Buffer space is defined as the default or specified 165 * space, minus the length of the utility name and arguments. Set up 166 * begin/end/traversing pointers into the array. The -s count does 167 * include the trailing NULL, so the malloc didn't add in an extra 168 * slot. 169 */ 170 nline -= cnt; 171 if (nline <= 0) 172 errx(1, "insufficient space for command"); 173 174 if (!(bbp = malloc((u_int)nline + 1))) 175 err(1, "malloc"); 176 ebp = (argp = p = bbp) + nline - 1; 177 178 if (pflag) { 179 int error; 180 181 if ((promptfile = fopen(_PATH_TTY, "r")) == NULL) 182 err(1, "prompt mode: cannot open input"); 183 if ((error = regcomp(&yesexpr, nl_langinfo(YESEXPR), REG_NOSUB)) 184 != 0) { 185 char msg[NL_TEXTMAX]; 186 187 (void)regerror(error, NULL, msg, sizeof (msg)); 188 err(1, "cannot compile yesexpr: %s", msg); 189 } 190 } 191 192 for (insingle = indouble = 0;;) 193 switch(ch = getchar()) { 194 case EOF: 195 /* No arguments since last exec. */ 196 if (p == bbp) 197 exit(rval); 198 199 /* Nothing since end of last argument. */ 200 if (argp == p) { 201 *xp = NULL; 202 run(av); 203 exit(rval); 204 } 205 goto arg1; 206 case ' ': 207 case '\t': 208 /* Quotes escape tabs and spaces. */ 209 if (insingle || indouble || zflag) 210 goto addch; 211 goto arg2; 212 case '\0': 213 if (zflag) 214 goto arg2; 215 goto addch; 216 case '\n': 217 if (zflag) 218 goto addch; 219 /* Empty lines are skipped. */ 220 if (argp == p) 221 continue; 222 223 /* Quotes do not escape newlines. */ 224 arg1: if (insingle || indouble) 225 errx(1, "unterminated quote"); 226 227 arg2: *p = '\0'; 228 *xp++ = argp; 229 230 /* 231 * If max'd out on args or buffer, or reached EOF, 232 * run the command. If xflag and max'd out on buffer 233 * but not on args, object. 234 */ 235 if (xp == exp || p == ebp || ch == EOF) { 236 if (xflag && xp != exp && p == ebp) 237 errx(1, "insufficient space for arguments"); 238 *xp = NULL; 239 run(av); 240 if (ch == EOF) 241 exit(rval); 242 p = bbp; 243 xp = bxp; 244 } else 245 ++p; 246 argp = p; 247 break; 248 case '\'': 249 if (indouble || zflag) 250 goto addch; 251 insingle = !insingle; 252 break; 253 case '"': 254 if (insingle || zflag) 255 goto addch; 256 indouble = !indouble; 257 break; 258 case '\\': 259 if (zflag) 260 goto addch; 261 /* Backslash escapes anything, is escaped by quotes. */ 262 if (!insingle && !indouble && (ch = getchar()) == EOF) 263 errx(1, "backslash at EOF"); 264 /* FALLTHROUGH */ 265 default: 266 addch: if (p < ebp) { 267 *p++ = ch; 268 break; 269 } 270 271 /* If only one argument, not enough buffer space. */ 272 if (bxp == xp) 273 errx(1, "insufficient space for argument"); 274 /* Didn't hit argument limit, so if xflag object. */ 275 if (xflag) 276 errx(1, "insufficient space for arguments"); 277 278 *xp = NULL; 279 run(av); 280 xp = bxp; 281 cnt = ebp - argp; 282 memmove(bbp, argp, cnt); 283 p = (argp = bbp) + cnt; 284 *p++ = ch; 285 break; 286 } 287 /* NOTREACHED */ 288 } 289 290 static void 291 run(argv) 292 char **argv; 293 { 294 volatile int noinvoke; 295 char **p; 296 pid_t pid; 297 int status; 298 299 if (tflag) { 300 (void)fprintf(stderr, "%s", *argv); 301 for (p = argv + 1; *p; ++p) 302 (void)fprintf(stderr, " %s", *p); 303 if (pflag) { 304 char buf[LINE_MAX + 1]; 305 306 (void)fprintf(stderr, "?..."); 307 fflush(stderr); 308 if (fgets(buf, sizeof (buf), promptfile) == NULL) { 309 rval = 1; 310 return; 311 } 312 if (regexec(&yesexpr, buf, 0, NULL, 0) != 0) 313 return; 314 } else { 315 (void)fprintf(stderr, "\n"); 316 } 317 } 318 noinvoke = 0; 319 switch(pid = vfork()) { 320 case -1: 321 err(1, "vfork"); 322 case 0: 323 execvp(argv[0], argv); 324 noinvoke = (errno == ENOENT) ? 127 : 126; 325 warn("%s", argv[0]); 326 _exit(1); 327 } 328 pid = waitpid(pid, &status, 0); 329 if (pid == -1) 330 err(1, "waitpid"); 331 332 /* 333 * If we couldn't invoke the utility or the utility didn't exit 334 * properly, quit with 127 or 126 respectively. 335 */ 336 if (noinvoke) 337 exit(noinvoke); 338 339 /* 340 * According to POSIX, we have to exit if the utility exits with 341 * a 255 status, or is interrupted by a signal. xargs is allowed 342 * to return any exit status between 1 and 125 in these cases, but 343 * we'll use 124 and 125, the same values used by GNU xargs. 344 */ 345 if (WIFEXITED(status)) { 346 if (WEXITSTATUS (status) == 255) { 347 warnx ("%s exited with status 255", argv[0]); 348 exit(124); 349 } else if (WEXITSTATUS (status) != 0) { 350 rval = 123; 351 } 352 } else if (WIFSIGNALED (status)) { 353 if (WTERMSIG(status) < NSIG) { 354 warnx("%s terminated by SIG%s", argv[0], 355 sys_signame[WTERMSIG(status)]); 356 } else { 357 warnx("%s terminated by signal %d", argv[0], 358 WTERMSIG(status)); 359 } 360 exit(125); 361 } 362 } 363 364 static void 365 usage() 366 { 367 (void)fprintf(stderr, 368 "usage: xargs [-0pt] [-n number [-x]] [-s size] [utility [argument ...]]\n"); 369 exit(1); 370 } 371