1 /* $NetBSD: apply.c,v 1.17 2008/03/08 03:35:53 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Jan-Simon Pendry. 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 #if 0 38 static char sccsid[] = "@(#)apply.c 8.4 (Berkeley) 4/4/94"; 39 #else 40 __RCSID("$NetBSD: apply.c,v 1.17 2008/03/08 03:35:53 christos Exp $"); 41 #endif 42 #endif /* not lint */ 43 44 #include <sys/wait.h> 45 46 #include <ctype.h> 47 #include <err.h> 48 #include <paths.h> 49 #include <signal.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 55 static void usage(void) __dead; 56 static int shell_system(const char *); 57 58 int 59 main(int argc, char *argv[]) 60 { 61 size_t clen, l; 62 int ch, debug, i, magic, n, nargs, rval; 63 char *c, *cmd, *p, *q, *nc; 64 65 (void)setprogname(argv[0]); /* for portability */ 66 67 debug = 0; 68 magic = '%'; /* Default magic char is `%'. */ 69 nargs = -1; 70 while ((ch = getopt(argc, argv, "a:d0123456789")) != -1) { 71 switch (ch) { 72 case 'a': 73 if (optarg[1] != '\0') 74 errx(EXIT_FAILURE, 75 "illegal magic character specification."); 76 magic = optarg[0]; 77 break; 78 case 'd': 79 debug = 1; 80 break; 81 case '0': case '1': case '2': case '3': case '4': 82 case '5': case '6': case '7': case '8': case '9': 83 if (nargs != -1) 84 errx(EXIT_FAILURE, 85 "only one -# argument may be specified."); 86 nargs = optopt - '0'; 87 break; 88 default: 89 usage(); 90 } 91 } 92 argc -= optind; 93 argv += optind; 94 95 if (argc < 2) 96 usage(); 97 98 /* 99 * The command to run is argv[0], and the args are argv[1..]. 100 * Look for %digit references in the command, remembering the 101 * largest one. 102 */ 103 for (n = 0, p = argv[0]; *p != '\0'; ++p) { 104 if (p[0] == magic && isdigit((unsigned char)p[1]) && 105 p[1] != '0') { 106 ++p; 107 if (p[0] - '0' > n) 108 n = p[0] - '0'; 109 } 110 } 111 /* 112 * If there were any %digit references, then use those, otherwise 113 * build a new command string with sufficient %digit references at 114 * the end to consume (nargs) arguments each time round the loop. 115 * Allocate enough space to hold the maximum command. 116 */ 117 if ((cmd = malloc(sizeof("exec ") - 1 + 118 strlen(argv[0]) + 9 * (sizeof(" %1") - 1) + 1)) == NULL) 119 err(EXIT_FAILURE, "malloc"); 120 121 if (n == 0) { 122 /* If nargs not set, default to a single argument. */ 123 if (nargs == -1) 124 nargs = 1; 125 126 p = cmd; 127 p += sprintf(cmd, "exec %s", argv[0]); 128 for (i = 1; i <= nargs; i++) 129 p += sprintf(p, " %c%d", magic, i); 130 131 /* 132 * If nargs set to the special value 0, eat a single 133 * argument for each command execution. 134 */ 135 if (nargs == 0) 136 nargs = 1; 137 } else { 138 (void)sprintf(cmd, "exec %s", argv[0]); 139 nargs = n; 140 } 141 142 /* 143 * Grab some space in which to build the command. Allocate 144 * as necessary later, but no reason to build it up slowly 145 * for the normal case. 146 */ 147 if ((c = malloc(clen = 1024)) == NULL) 148 err(EXIT_FAILURE, "malloc"); 149 150 /* 151 * (argc) and (argv) are still offset by one to make it simpler to 152 * expand %digit references. At the end of the loop check for (argc) 153 * equals 1 means that all the (argv) has been consumed. 154 */ 155 for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) { 156 /* 157 * Find a max value for the command length, and ensure 158 * there's enough space to build it. 159 */ 160 for (l = strlen(cmd), i = 0; i < nargs; i++) 161 l += strlen(argv[i+1]); 162 if (l > clen) { 163 nc = realloc(c, l); 164 if (nc == NULL) 165 err(EXIT_FAILURE, "malloc"); 166 c = nc; 167 clen = l; 168 } 169 170 /* Expand command argv references. */ 171 for (p = cmd, q = c; *p != '\0'; ++p) { 172 if (p[0] == magic && isdigit((unsigned char)p[1]) && 173 p[1] != '0') 174 q += sprintf(q, "%s", argv[(++p)[0] - '0']); 175 else 176 *q++ = *p; 177 } 178 179 /* Terminate the command string. */ 180 *q = '\0'; 181 182 /* Run the command. */ 183 if (debug) 184 (void)printf("%s\n", c); 185 else if (shell_system(c)) 186 rval = 1; 187 } 188 189 if (argc != 1) 190 errx(EXIT_FAILURE, 191 "expecting additional argument%s after \"%s\"", 192 (nargs - argc) ? "s" : "", argv[argc - 1]); 193 return rval; 194 } 195 196 /* 197 * shell_system -- 198 * Private version of system(3). Use the user's SHELL environment 199 * variable as the shell to execute. 200 */ 201 static int 202 shell_system(const char *command) 203 { 204 static const char *name, *shell; 205 int status; 206 int omask; 207 pid_t pid; 208 sig_t intsave, quitsave; 209 210 if (shell == NULL) { 211 if ((shell = getenv("SHELL")) == NULL) 212 shell = _PATH_BSHELL; 213 if ((name = strrchr(shell, '/')) == NULL) 214 name = shell; 215 else 216 ++name; 217 } 218 if (!command) /* just checking... */ 219 return(1); 220 221 omask = sigblock(sigmask(SIGCHLD)); 222 switch (pid = vfork()) { 223 case -1: /* error */ 224 err(EXIT_FAILURE, "vfork"); 225 /*NOTREACHED*/ 226 case 0: /* child */ 227 (void)sigsetmask(omask); 228 (void)execl(shell, name, "-c", command, NULL); 229 warn("%s", shell); 230 _exit(1); 231 /*NOTREACHED*/ 232 default: /* parent */ 233 intsave = signal(SIGINT, SIG_IGN); 234 quitsave = signal(SIGQUIT, SIG_IGN); 235 pid = waitpid(pid, &status, 0); 236 (void)sigsetmask(omask); 237 (void)signal(SIGINT, intsave); 238 (void)signal(SIGQUIT, quitsave); 239 return pid == -1 ? -1 : status; 240 } 241 /*NOTREACHED*/ 242 } 243 244 __dead 245 static void 246 usage(void) 247 { 248 249 (void)fprintf(stderr, 250 "usage: %s [-a magic] [-0123456789] command arguments ...\n", 251 getprogname()); 252 exit(1); 253 } 254