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 37 #include <sys/cdefs.h> 38 39 __FBSDID("$FreeBSD$"); 40 41 #ifndef lint 42 static const char copyright[] = 43 "@(#) Copyright (c) 1990, 1993\n\ 44 The Regents of the University of California. All rights reserved.\n"; 45 #endif 46 47 #ifndef lint 48 static const char sccsid[] = "@(#)xargs.c 8.1 (Berkeley) 6/6/93"; 49 #endif 50 51 #include <sys/types.h> 52 #include <sys/wait.h> 53 54 #include <err.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 60 #include "pathnames.h" 61 62 int tflag, rval; 63 int zflag; 64 65 void run __P((char **)); 66 static void usage __P((void)); 67 68 static char echo[] = _PATH_ECHO; 69 70 int 71 main(argc, argv, env) 72 int argc; 73 char **argv, **env; 74 { 75 int ch; 76 char *p, *bbp, **bxp, *ebp, **exp, **xp; 77 int cnt, jfound, indouble, insingle; 78 int nargs, nflag, nline, xflag, wasquoted; 79 char **av, **avj, *argp, **ep, *replstr; 80 long arg_max; 81 82 ep = env; 83 jfound = 0; 84 replstr = NULL; /* set if user requests -J */ 85 86 /* 87 * POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that 88 * caused some E2BIG errors, so it was changed to ARG_MAX - 4K. Given 89 * that the smallest argument is 2 bytes in length, this means that 90 * the number of arguments is limited to: 91 * 92 * (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2. 93 * 94 * We arbitrarily limit the number of arguments to 5000. This is 95 * allowed by POSIX.2 as long as the resulting minimum exec line is 96 * at least LINE_MAX. Realloc'ing as necessary is possible, but 97 * probably not worthwhile. 98 */ 99 nargs = 5000; 100 if ((arg_max = sysconf(_SC_ARG_MAX)) == -1) 101 errx(1, "sysconf(_SC_ARG_MAX) failed"); 102 nline = arg_max - 4 * 1024; 103 while (*ep) { 104 /* 1 byte for each '\0' */ 105 nline -= strlen(*ep++) + 1 + sizeof(*ep); 106 } 107 nflag = xflag = wasquoted = 0; 108 while ((ch = getopt(argc, argv, "0J:n:s:tx")) != -1) 109 switch(ch) { 110 case 'J': 111 replstr = optarg; 112 break; 113 case 'n': 114 nflag = 1; 115 if ((nargs = atoi(optarg)) <= 0) 116 errx(1, "illegal argument count"); 117 break; 118 case 's': 119 nline = atoi(optarg); 120 break; 121 case 't': 122 tflag = 1; 123 break; 124 case 'x': 125 xflag = 1; 126 break; 127 case '0': 128 zflag = 1; 129 break; 130 case '?': 131 default: 132 usage(); 133 } 134 argc -= optind; 135 argv += optind; 136 137 if (xflag && !nflag) 138 usage(); 139 140 /* 141 * Allocate pointers for the utility name, the utility arguments, 142 * the maximum arguments to be read from stdin and the trailing 143 * NULL. 144 */ 145 if (!(av = bxp = 146 malloc((u_int)(1 + argc + nargs + 1) * sizeof(char **)))) 147 errx(1, "malloc"); 148 149 /* 150 * Use the user's name for the utility as argv[0], just like the 151 * shell. Echo is the default. Set up pointers for the user's 152 * arguments. 153 */ 154 if (!*argv) 155 cnt = strlen((*bxp++ = echo)); 156 else { 157 cnt = 0; 158 do { 159 if (replstr && strcmp(*argv, replstr) == 0) { 160 jfound = 1; 161 argv++; 162 for (avj = argv; *avj; avj++) 163 cnt += strlen(*avj) + 1; 164 break; 165 } 166 cnt += strlen(*bxp++ = *argv) + 1; 167 } while (*++argv); 168 } 169 170 /* 171 * Set up begin/end/traversing pointers into the array. The -n 172 * count doesn't include the trailing NULL pointer, so the malloc 173 * added in an extra slot. 174 */ 175 exp = (xp = bxp) + nargs; 176 177 /* 178 * Allocate buffer space for the arguments read from stdin and the 179 * trailing NULL. Buffer space is defined as the default or specified 180 * space, minus the length of the utility name and arguments. Set up 181 * begin/end/traversing pointers into the array. The -s count does 182 * include the trailing NULL, so the malloc didn't add in an extra 183 * slot. 184 */ 185 nline -= cnt; 186 if (nline <= 0) 187 errx(1, "insufficient space for command"); 188 189 if (!(bbp = malloc((u_int)nline + 1))) 190 errx(1, "malloc"); 191 ebp = (argp = p = bbp) + nline - 1; 192 193 for (insingle = indouble = 0;;) 194 switch(ch = getchar()) { 195 case EOF: 196 /* No arguments since last exec. */ 197 if (p == bbp) 198 exit(rval); 199 goto arg1; 200 case ' ': 201 case '\t': 202 /* Quotes escape tabs and spaces. */ 203 if (insingle || indouble || zflag) 204 goto addch; 205 goto arg2; 206 case '\0': 207 if (zflag) 208 goto arg2; 209 goto addch; 210 case '\n': 211 if (zflag) 212 goto addch; 213 214 /* Quotes do not escape newlines. */ 215 arg1: if (insingle || indouble) 216 errx(1, "unterminated quote"); 217 218 arg2: 219 /* Do not make empty args unless they are quoted */ 220 if (argp != p || wasquoted) { 221 *p++ = '\0'; 222 *xp++ = argp; 223 } 224 225 /* 226 * If max'd out on args or buffer, or reached EOF, 227 * run the command. If xflag and max'd out on buffer 228 * but not on args, object. 229 */ 230 if (xp == exp || p > ebp || ch == EOF) { 231 if (xflag && xp != exp && p > ebp) 232 errx(1, "insufficient space for arguments"); 233 if (jfound) { 234 for (avj = argv; *avj; avj++) 235 *xp++ = *avj; 236 } 237 *xp = NULL; 238 run(av); 239 if (ch == EOF) 240 exit(rval); 241 p = bbp; 242 xp = bxp; 243 } 244 argp = p; 245 wasquoted = 0; 246 break; 247 case '\'': 248 if (indouble || zflag) 249 goto addch; 250 insingle = !insingle; 251 wasquoted = 1; 252 break; 253 case '"': 254 if (insingle || zflag) 255 goto addch; 256 indouble = !indouble; 257 wasquoted = 1; 258 break; 259 case '\\': 260 if (zflag) 261 goto addch; 262 /* Backslash escapes anything, is escaped by quotes. */ 263 if (!insingle && !indouble && (ch = getchar()) == EOF) 264 errx(1, "backslash at EOF"); 265 /* FALLTHROUGH */ 266 default: 267 addch: if (p < ebp) { 268 *p++ = ch; 269 break; 270 } 271 272 /* If only one argument, not enough buffer space. */ 273 if (bxp == xp) 274 errx(1, "insufficient space for argument"); 275 /* Didn't hit argument limit, so if xflag object. */ 276 if (xflag) 277 errx(1, "insufficient space for arguments"); 278 279 if (jfound) { 280 for (avj = argv; *avj; avj++) 281 *xp++ = *avj; 282 } 283 *xp = NULL; 284 run(av); 285 xp = bxp; 286 cnt = ebp - argp; 287 bcopy(argp, bbp, cnt); 288 p = (argp = bbp) + cnt; 289 *p++ = ch; 290 break; 291 } 292 /* NOTREACHED */ 293 } 294 295 void 296 run(argv) 297 char **argv; 298 { 299 volatile int noinvoke; 300 char **p; 301 pid_t pid; 302 int status; 303 304 if (tflag) { 305 (void)fprintf(stderr, "%s", *argv); 306 for (p = argv + 1; *p; ++p) 307 (void)fprintf(stderr, " %s", *p); 308 (void)fprintf(stderr, "\n"); 309 (void)fflush(stderr); 310 } 311 noinvoke = 0; 312 switch(pid = fork()) { 313 case -1: 314 err(1, "fork"); 315 case 0: 316 execvp(argv[0], argv); 317 warn("%s", argv[0]); 318 noinvoke = 1; 319 _exit(1); 320 } 321 pid = waitpid(pid, &status, 0); 322 if (pid == -1) 323 err(1, "waitpid"); 324 /* If we couldn't invoke the utility, exit 127. */ 325 if (noinvoke) 326 exit(127); 327 /* If utility signaled or exited with a value of 255, exit 1-125. */ 328 if (WIFSIGNALED(status) || WEXITSTATUS(status) == 255) 329 exit(1); 330 if (WEXITSTATUS(status)) 331 rval = 1; 332 } 333 334 static void 335 usage() 336 { 337 fprintf(stderr, 338 "usage: xargs [-0t] [-J replstr] [-n number [-x]] [-s size]\n" 339 " [utility [argument ...]]\n"); 340 exit(1); 341 } 342