usr.bin/apply/apply.c

   1 /*      $NetBSD: apply.c,v 1.16 2005/05/08 19:53:57 matt 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 1.16 2005/05/08 19:53:57 matt 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 }