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  */
  35
  36 #include <sys/types.h>
  37
  38 #include <sys/wait.h>
  39
  40 #include <ctype.h>
  41 #include <err.h>
  42 #include <paths.h>
  43 #include <signal.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <unistd.h>
  48
  49 #define EXEC    "exec "
  50
  51 static int      exec_shell(const char *, const char *, const char *);
  52 static void     usage(void);
  53
  54 int
  55 main(int argc, char *argv[])
  56 {
  57         int ch, debug, i, magic, n, nargs, offset, rval;
  58         size_t clen, cmdsize, l;
  59         char *c, *cmd, *name, *p, *q, *shell, *slashp, *tmpshell;
  60
  61         debug = 0;
  62         magic = '%';            /* Default magic char is `%'. */
  63         nargs = -1;
  64         while ((ch = getopt(argc, argv, "a:d0123456789")) != -1)
  65                 switch (ch) {
  66                 case 'a':
  67                         if (optarg[1] != '\0')
  68                                 errx(1,
  69                                     "illegal magic character specification");
  70                         magic = optarg[0];
  71                         break;
  72                 case 'd':
  73                         debug = 1;
  74                         break;
  75                 case '0': case '1': case '2': case '3': case '4':
  76                 case '5': case '6': case '7': case '8': case '9':
  77                         if (nargs != -1)
  78                                 errx(1,
  79                                     "only one -# argument may be specified");
  80                         nargs = optopt - '0';
  81                         break;
  82                 default:
  83                         usage();
  84                 }
  85         argc -= optind;
  86         argv += optind;
  87
  88         if (argc < 2)
  89                 usage();
  90
  91         /*
  92          * The command to run is argv[0], and the args are argv[1..].
  93          * Look for %digit references in the command, remembering the
  94          * largest one.
  95          */
  96         for (n = 0, p = argv[0]; *p != '\0'; ++p)
  97                 if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
  98                         ++p;
  99                         if (p[0] - '0' > n)
 100                                 n = p[0] - '0';
 101                 }
 102
 103         /*
 104          * Figure out the shell and name arguments to pass to execl()
 105          * in exec_shell().  Always malloc() shell and just set name
 106          * to point at the last part of shell if there are any backslashes,
 107          * otherwise just set it to point at the space malloc()'d.  If
 108          * SHELL environment variable exists, replace contents of
 109          * shell with it.
 110          */
 111         shell = name = NULL;
 112         tmpshell = getenv("SHELL");
 113         shell = (tmpshell != NULL) ? strdup(tmpshell) : strdup(_PATH_BSHELL);
 114         if (shell == NULL)
 115                 err(1, "strdup() failed");
 116         slashp = strrchr(shell, '/');
 117         name = (slashp != NULL) ? slashp + 1 : shell;
 118
 119         /*
 120          * If there were any %digit references, then use those, otherwise
 121          * build a new command string with sufficient %digit references at
 122          * the end to consume (nargs) arguments each time round the loop.
 123          * Allocate enough space to hold the maximum command.  Save the
 124          * size to pass to snprintf().
 125          */
 126         cmdsize = sizeof(EXEC) - 1 + strlen(argv[0])
 127             + 9 * (sizeof(" %1") - 1) + 1;
 128         if ((cmd = malloc(cmdsize)) == NULL)
 129                 err(1, NULL);
 130
 131         if (n == 0) {
 132                 /* If nargs not set, default to a single argument. */
 133                 if (nargs == -1)
 134                         nargs = 1;
 135
 136                 p = cmd;
 137                 offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
 138                 if ((size_t)offset >= cmdsize)
 139                         err(1, "snprintf() failed");
 140                 p += offset;
 141                 cmdsize -= offset;
 142                 for (i = 1; i <= nargs; i++) {
 143                         offset = snprintf(p, cmdsize, " %c%d", magic, i);
 144                         if ((size_t)offset >= cmdsize)
 145                                 err(1, "snprintf() failed");
 146                         p += offset;
 147                         cmdsize -= offset;
 148                 }
 149
 150                 /*
 151                  * If nargs set to the special value 0, eat a single
 152                  * argument for each command execution.
 153                  */
 154                 if (nargs == 0)
 155                         nargs = 1;
 156         } else {
 157                 offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
 158                 if ((size_t)offset >= cmdsize)
 159                         err(1, "snprintf() failed");
 160                 nargs = n;
 161         }
 162
 163         /*
 164          * Grab some space in which to build the command.  Allocate
 165          * as necessary later, but no reason to build it up slowly
 166          * for the normal case.
 167          */
 168         if ((c = malloc(clen = 1024)) == NULL)
 169                 err(1, NULL);
 170
 171         /*
 172          * (argc) and (argv) are still offset by one to make it simpler to
 173          * expand %digit references.  At the end of the loop check for (argc)
 174          * equals 1 means that all the (argv) has been consumed.
 175          */
 176         for (rval = 0; argc > nargs; argc -= nargs, argv += nargs) {
 177                 /*
 178                  * Find a max value for the command length, and ensure
 179                  * there's enough space to build it.
 180                  */
 181                 for (l = strlen(cmd), i = 0; i < nargs; i++)
 182                         l += strlen(argv[i+1]);
 183                 if (l > clen && (c = realloc(c, clen = l)) == NULL)
 184                         err(1, NULL);
 185
 186                 /* Expand command argv references. */
 187                 for (p = cmd, q = c; *p != '\0'; ++p) {
 188                         if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
 189                                 offset = snprintf(q, l, "%s",
 190                                     argv[(++p)[0] - '0']);
 191                                 if ((size_t)offset >= l)
 192                                         err(1, "snprintf() failed");
 193                                 q += offset;
 194                                 l -= offset;
 195                         } else {
 196                                 *q++ = *p;
 197                         }
 198                 }
 199
 200                 /* Terminate the command string. */
 201                 *q = '\0';
 202
 203                 /* Run the command. */
 204                 if (debug) {
 205                         printf("%s\n", c);
 206                 } else {
 207                         if (exec_shell(c, shell, name))
 208                                 rval = 1;
 209                 }
 210         }
 211
 212         if (argc != 1)
 213                 errx(1, "expecting additional argument%s after \"%s\"",
 214             (nargs - argc) ? "s" : "", argv[argc - 1]);
 215         free(cmd);
 216         free(c);
 217         free(shell);
 218         exit(rval);
 219 }
 220
 221 /*
 222  * exec_shell --
 223  *      Execute a shell command using passed use_shell and use_name
 224  *      arguments.
 225  */
 226 static int
 227 exec_shell(const char *command, const char *use_shell, const char *use_name)
 228 {
 229         pid_t pid;
 230         int omask, pstat;
 231         sig_t intsave, quitsave;
 232
 233         if (command == NULL)            /* just checking... */
 234                 return(1);
 235
 236         omask = sigblock(sigmask(SIGCHLD));
 237         switch(pid = vfork()) {
 238         case -1:                        /* error */
 239                 err(1, "vfork");
 240         case 0:                         /* child */
 241                 (void)sigsetmask(omask);
 242                 execl(use_shell, use_name, "-c", command, NULL);
 243                 warn("%s", use_shell);
 244                 _exit(1);
 245         }
 246         intsave = signal(SIGINT, SIG_IGN);
 247         quitsave = signal(SIGQUIT, SIG_IGN);
 248         pid = waitpid(pid, &pstat, 0);
 249         sigsetmask(omask);
 250         signal(SIGINT, intsave);
 251         signal(SIGQUIT, quitsave);
 252         return(pid == -1 ? -1 : pstat);
 253 }
 254
 255 static void
 256 usage(void)
 257 {
 258         fprintf(stderr,
 259             "usage: apply [-a magic] [-d] [-0123456789] "
 260             "command arguments ...\n");
 261         exit(1);
 262 }