usr.bin/apply/apply.c

   1 /*-
   2  * Copyright (c) 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Jan-Simon Pendry.
   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. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * @(#)apply.c  8.4 (Berkeley) 4/4/94
  33  * $FreeBSD: src/usr.bin/apply/apply.c,v 1.8.2.3 2001/08/01 23:28:04 obrien Exp $
  34  * $DragonFly: src/usr.bin/apply/apply.c,v 1.5 2005/01/04 05:45:02 cpressey Exp $
  35  */
  36
  37 #include <sys/types.h>
  38
  39 #include <sys/wait.h>
  40
  41 #include <ctype.h>
  42 #include <err.h>
  43 #include <paths.h>
  44 #include <signal.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49
  50 #define EXEC    "exec "
  51
  52 static int      exec_shell(const char *, char *, char *);
  53 static void     usage(void);
  54
  55 int
  56 main(int argc, char *argv[])
  57 {
  58         int ch, debug, i, magic, n, nargs, offset, rval;
  59         size_t clen, cmdsize, l;
  60         char *c, *cmd, *name, *p, *q, *shell, *slashp, *tmpshell;
  61
  62         debug = 0;
  63         magic = '%';            /* Default magic char is `%'. */
  64         nargs = -1;
  65         while ((ch = getopt(argc, argv, "a:d0123456789")) != -1)
  66                 switch (ch) {
  67                 case 'a':
  68                         if (optarg[1] != '\0')
  69                                 errx(1,
  70                                     "illegal magic character specification");
  71                         magic = optarg[0];
  72                         break;
  73                 case 'd':
  74                         debug = 1;
  75                         break;
  76                 case '0': case '1': case '2': case '3': case '4':
  77                 case '5': case '6': case '7': case '8': case '9':
  78                         if (nargs != -1)
  79                                 errx(1,
  80                                     "only one -# argument may be specified");
  81                         nargs = optopt - '0';
  82                         break;
  83                 default:
  84                         usage();
  85                 }
  86         argc -= optind;
  87         argv += optind;
  88
  89         if (argc < 2)
  90                 usage();
  91
  92         /*
  93          * The command to run is argv[0], and the args are argv[1..].
  94          * Look for %digit references in the command, remembering the
  95          * largest one.
  96          */
  97         for (n = 0, p = argv[0]; *p != '\0'; ++p)
  98                 if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
  99                         ++p;
 100                         if (p[0] - '0' > n)
 101                                 n = p[0] - '0';
 102                 }
 103
 104         /*
 105          * Figure out the shell and name arguments to pass to execl()
 106          * in exec_shell().  Always malloc() shell and just set name
 107          * to point at the last part of shell if there are any backslashes,
 108          * otherwise just set it to point at the space malloc()'d.  If
 109          * SHELL environment variable exists, replace contents of
 110          * shell with it.
 111          */
 112         shell = name = NULL;
 113         tmpshell = getenv("SHELL");
 114         shell = (tmpshell != NULL) ? strdup(tmpshell) : strdup(_PATH_BSHELL);
 115         if (shell == NULL)
 116                 err(1, "strdup() failed");
 117         slashp = strrchr(shell, '/');
 118         name = (slashp != NULL) ? slashp + 1 : shell;
 119
 120         /*
 121          * If there were any %digit references, then use those, otherwise
 122          * build a new command string with sufficient %digit references at
 123          * the end to consume (nargs) arguments each time round the loop.
 124          * Allocate enough space to hold the maximum command.  Save the
 125          * size to pass to snprintf().
 126          */
 127         cmdsize = sizeof(EXEC) - 1 + strlen(argv[0])
 128             + 9 * (sizeof(" %1") - 1) + 1;
 129         if ((cmd = malloc(cmdsize)) == NULL)
 130                 err(1, NULL);
 131
 132         if (n == 0) {
 133                 /* If nargs not set, default to a single argument. */
 134                 if (nargs == -1)
 135                         nargs = 1;
 136
 137                 p = cmd;
 138                 offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
 139                 if ((size_t)offset >= cmdsize)
 140                         err(1, "snprintf() failed");
 141                 p += offset;
 142                 cmdsize -= offset;
 143                 for (i = 1; i <= nargs; i++) {
 144                         offset = snprintf(p, cmdsize, " %c%d", magic, i);
 145                         if ((size_t)offset >= cmdsize)
 146                                 err(1, "snprintf() failed");
 147                         p += offset;
 148                         cmdsize -= offset;
 149                 }
 150
 151                 /*
 152                  * If nargs set to the special value 0, eat a single
 153                  * argument for each command execution.
 154                  */
 155                 if (nargs == 0)
 156                         nargs = 1;
 157         } else {
 158                 offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
 159                 if ((size_t)offset >= cmdsize)
 160                         err(1, "snprintf() failed");
 161                 nargs = n;
 162         }
 163
 164         /*
 165          * Grab some space in which to build the command.  Allocate
 166          * as necessary later, but no reason to build it up slowly
 167          * for the normal case.
 168          */
 169         if ((c = malloc(clen = 1024)) == NULL)
 170                 err(1, NULL);
 171
 172         /*
 173          * (argc) and (argv) are still offset by one to make it simpler to
 174          * expand %digit references.  At the end of the loop check for (argc)
 175          * equals 1 means that all the (argv) has been consumed.
 176          */
 177         for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
 178                 /*
 179                  * Find a max value for the command length, and ensure
 180                  * there's enough space to build it.
 181                  */
 182                 for (l = strlen(cmd), i = 0; i < nargs; i++)
 183                         l += strlen(argv[i+1]);
 184                 if (l > clen && (c = realloc(c, clen = l)) == NULL)
 185                         err(1, NULL);
 186
 187                 /* Expand command argv references. */
 188                 for (p = cmd, q = c; *p != '\0'; ++p) {
 189                         if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
 190                                 offset = snprintf(q, l, "%s",
 191                                     argv[(++p)[0] - '0']);
 192                                 if ((size_t)offset >= l)
 193                                         err(1, "snprintf() failed");
 194                                 q += offset;
 195                                 l -= offset;
 196                         } else {
 197                                 *q++ = *p;
 198                         }
 199                 }
 200
 201                 /* Terminate the command string. */
 202                 *q = '\0';
 203
 204                 /* Run the command. */
 205                 if (debug) {
 206                         printf("%s\n", c);
 207                 } else {
 208                         if (exec_shell(c, shell, name))
 209                                 rval = 1;
 210                 }
 211         }
 212
 213         if (argc != 1)
 214                 errx(1, "expecting additional argument%s after \"%s\"",
 215             (nargs - argc) ? "s" : "", argv[argc - 1]);
 216         free(cmd);
 217         free(c);
 218         free(shell);
 219         exit(rval);
 220 }
 221
 222 /*
 223  * exec_shell --
 224  *      Execute a shell command using passed use_shell and use_name
 225  *      arguments.
 226  */
 227 static int
 228 exec_shell(const char *command, char *use_shell, char *use_name)
 229 {
 230         pid_t pid;
 231         int omask, pstat;
 232         sig_t intsave, quitsave;
 233
 234         if (command == NULL)            /* just checking... */
 235                 return(1);
 236
 237         omask = sigblock(sigmask(SIGCHLD));
 238         switch(pid = vfork()) {
 239         case -1:                        /* error */
 240                 err(1, "vfork");
 241         case 0:                         /* child */
 242                 (void)sigsetmask(omask);
 243                 execl(use_shell, use_name, "-c", command, NULL);
 244                 warn("%s", use_shell);
 245                 _exit(1);
 246         }
 247         intsave = signal(SIGINT, SIG_IGN);
 248         quitsave = signal(SIGQUIT, SIG_IGN);
 249         pid = waitpid(pid, &pstat, 0);
 250         sigsetmask(omask);
 251         signal(SIGINT, intsave);
 252         signal(SIGQUIT, quitsave);
 253         return(pid == -1 ? -1 : pstat);
 254 }
 255
 256 void
 257 usage(void)
 258 {
 259         fprintf(stderr,
 260             "usage: apply [-a magic] [-d] [-0123456789] "
 261             "command arguments ...\n");
 262         exit(1);
 263 }