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 #ifndef lint 38 static char copyright[] = 39 "@(#) Copyright (c) 1990, 1993\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 static char sccsid[] = "@(#)xargs.c 8.1 (Berkeley) 6/6/93"; 45 #endif /* not lint */ 46 47 #include <sys/types.h> 48 #include <sys/wait.h> 49 #include <errno.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 #include <limits.h> 55 #include "pathnames.h" 56 57 int tflag, rval; 58 59 void err __P((const char *, ...)); 60 void run __P((char **)); 61 void usage __P((void)); 62 63 main(argc, argv) 64 int argc; 65 char **argv; 66 { 67 register int ch; 68 register char *p, *bbp, *ebp, **bxp, **exp, **xp; 69 int cnt, indouble, insingle, nargs, nflag, nline, xflag; 70 char **av, *argp; 71 72 /* 73 * POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that 74 * caused some E2BIG errors, so it was changed to ARG_MAX - 4K. Given 75 * that the smallest argument is 2 bytes in length, this means that 76 * the number of arguments is limited to: 77 * 78 * (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2. 79 * 80 * We arbitrarily limit the number of arguments to 5000. This is 81 * allowed by POSIX.2 as long as the resulting minimum exec line is 82 * at least LINE_MAX. Realloc'ing as necessary is possible, but 83 * probably not worthwhile. 84 */ 85 nargs = 5000; 86 nline = ARG_MAX - 4 * 1024; 87 nflag = xflag = 0; 88 while ((ch = getopt(argc, argv, "n:s:tx")) != EOF) 89 switch(ch) { 90 case 'n': 91 nflag = 1; 92 if ((nargs = atoi(optarg)) <= 0) 93 err("illegal argument count"); 94 break; 95 case 's': 96 nline = atoi(optarg); 97 break; 98 case 't': 99 tflag = 1; 100 break; 101 case 'x': 102 xflag = 1; 103 break; 104 case '?': 105 default: 106 usage(); 107 } 108 argc -= optind; 109 argv += optind; 110 111 if (xflag && !nflag) 112 usage(); 113 114 /* 115 * Allocate pointers for the utility name, the utility arguments, 116 * the maximum arguments to be read from stdin and the trailing 117 * NULL. 118 */ 119 if (!(av = bxp = 120 malloc((u_int)(1 + argc + nargs + 1) * sizeof(char **)))) 121 err("%s", strerror(errno)); 122 123 /* 124 * Use the user's name for the utility as argv[0], just like the 125 * shell. Echo is the default. Set up pointers for the user's 126 * arguments. 127 */ 128 if (!*argv) 129 cnt = strlen(*bxp++ = _PATH_ECHO); 130 else { 131 cnt = 0; 132 do { 133 cnt += strlen(*bxp++ = *argv) + 1; 134 } while (*++argv); 135 } 136 137 /* 138 * Set up begin/end/traversing pointers into the array. The -n 139 * count doesn't include the trailing NULL pointer, so the malloc 140 * added in an extra slot. 141 */ 142 exp = (xp = bxp) + nargs; 143 144 /* 145 * Allocate buffer space for the arguments read from stdin and the 146 * trailing NULL. Buffer space is defined as the default or specified 147 * space, minus the length of the utility name and arguments. Set up 148 * begin/end/traversing pointers into the array. The -s count does 149 * include the trailing NULL, so the malloc didn't add in an extra 150 * slot. 151 */ 152 nline -= cnt; 153 if (nline <= 0) 154 err("insufficient space for command"); 155 156 if (!(bbp = malloc((u_int)nline + 1))) 157 err("%s", strerror(errno)); 158 ebp = (argp = p = bbp) + nline - 1; 159 160 for (insingle = indouble = 0;;) 161 switch(ch = getchar()) { 162 case EOF: 163 /* No arguments since last exec. */ 164 if (p == bbp) 165 exit(rval); 166 167 /* Nothing since end of last argument. */ 168 if (argp == p) { 169 *xp = NULL; 170 run(av); 171 exit(rval); 172 } 173 goto arg1; 174 case ' ': 175 case '\t': 176 /* Quotes escape tabs and spaces. */ 177 if (insingle || indouble) 178 goto addch; 179 goto arg2; 180 case '\n': 181 /* Empty lines are skipped. */ 182 if (argp == p) 183 continue; 184 185 /* Quotes do not escape newlines. */ 186 arg1: if (insingle || indouble) 187 err("unterminated quote"); 188 189 arg2: *p = '\0'; 190 *xp++ = argp; 191 192 /* 193 * If max'd out on args or buffer, or reached EOF, 194 * run the command. If xflag and max'd out on buffer 195 * but not on args, object. 196 */ 197 if (xp == exp || p == ebp || ch == EOF) { 198 if (xflag && xp != exp && p == ebp) 199 err("insufficient space for arguments"); 200 *xp = NULL; 201 run(av); 202 if (ch == EOF) 203 exit(rval); 204 p = bbp; 205 xp = bxp; 206 } else 207 ++p; 208 argp = p; 209 break; 210 case '\'': 211 if (indouble) 212 goto addch; 213 insingle = !insingle; 214 break; 215 case '"': 216 if (insingle) 217 goto addch; 218 indouble = !indouble; 219 break; 220 case '\\': 221 /* Backslash escapes anything, is escaped by quotes. */ 222 if (!insingle && !indouble && (ch = getchar()) == EOF) 223 err("backslash at EOF"); 224 /* FALLTHROUGH */ 225 default: 226 addch: if (p < ebp) { 227 *p++ = ch; 228 break; 229 } 230 231 /* If only one argument, not enough buffer space. */ 232 if (bxp == xp) 233 err("insufficient space for argument"); 234 /* Didn't hit argument limit, so if xflag object. */ 235 if (xflag) 236 err("insufficient space for arguments"); 237 238 *xp = NULL; 239 run(av); 240 xp = bxp; 241 cnt = ebp - argp; 242 bcopy(argp, bbp, cnt); 243 p = (argp = bbp) + cnt; 244 *p++ = ch; 245 break; 246 } 247 /* NOTREACHED */ 248 } 249 250 void 251 run(argv) 252 char **argv; 253 { 254 volatile int noinvoke; 255 register char **p; 256 pid_t pid; 257 int status; 258 259 if (tflag) { 260 (void)fprintf(stderr, "%s", *argv); 261 for (p = argv + 1; *p; ++p) 262 (void)fprintf(stderr, " %s", *p); 263 (void)fprintf(stderr, "\n"); 264 (void)fflush(stderr); 265 } 266 noinvoke = 0; 267 switch(pid = vfork()) { 268 case -1: 269 err("vfork: %s", strerror(errno)); 270 case 0: 271 execvp(argv[0], argv); 272 (void)fprintf(stderr, 273 "xargs: %s: %s\n", argv[0], strerror(errno)); 274 noinvoke = 1; 275 _exit(1); 276 } 277 pid = waitpid(pid, &status, 0); 278 if (pid == -1) 279 err("waitpid: %s", strerror(errno)); 280 /* If we couldn't invoke the utility, exit 127. */ 281 if (noinvoke) 282 exit(127); 283 /* If utility signaled or exited with a value of 255, exit 1-125. */ 284 if (WIFSIGNALED(status) || WEXITSTATUS(status) == 255) 285 exit(1); 286 if (WEXITSTATUS(status)) 287 rval = 1; 288 } 289 290 void 291 usage() 292 { 293 (void)fprintf(stderr, 294 "usage: xargs [-t] [-n number [-x]] [-s size] [utility [argument ...]]\n"); 295 exit(1); 296 } 297 298 #if __STDC__ 299 #include <stdarg.h> 300 #else 301 #include <varargs.h> 302 #endif 303 304 void 305 #if __STDC__ 306 err(const char *fmt, ...) 307 #else 308 err(fmt, va_alist) 309 char *fmt; 310 va_dcl 311 #endif 312 { 313 va_list ap; 314 #if __STDC__ 315 va_start(ap, fmt); 316 #else 317 va_start(ap); 318 #endif 319 (void)fprintf(stderr, "xargs: "); 320 (void)vfprintf(stderr, fmt, ap); 321 va_end(ap); 322 (void)fprintf(stderr, "\n"); 323 exit(1); 324 /* NOTREACHED */ 325 } 326