usr.bin/env/env.c

   1 /*
   2  * Copyright (c) 1988, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#) Copyright (c) 1988, 1993, 1994 The Regents of the University of California.  All rights reserved.
  30  * @(#)env.c    8.3 (Berkeley) 4/2/94
  31  * $FreeBSD: src/usr.bin/env/env.c,v 1.5.2.3 2002/06/26 08:23:36 tjr Exp $
  32  * $DragonFly: src/usr.bin/env/env.c,v 1.5 2006/01/12 13:43:10 corecode Exp $
  33  */
  34
  35 #include <err.h>
  36 #include <errno.h>
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <stdlib.h>
  40 #include <unistd.h>
  41
  42 extern char **environ;
  43
  44 static void usage(void);
  45
  46 int
  47 main(int argc, char **argv)
  48 {
  49         char **ep, *p;
  50         char *cleanenv[1];
  51         int ch;
  52
  53         while ((ch = getopt(argc, argv, "-i")) != -1)
  54                 switch(ch) {
  55                 case '-':
  56                 case 'i':
  57                         environ = cleanenv;
  58                         cleanenv[0] = NULL;
  59                         break;
  60                 default:
  61                         usage();
  62                 }
  63         for (argv += optind; *argv && (p = strchr(*argv, '=')); ++argv) {
  64                 *p = '\0';
  65                 if (setenv(*argv, p + 1, 1) == -1)
  66                         err(1, "setenv: cannot set %s=%s", *argv, p + 1);
  67                 *p = '=';
  68         }
  69
  70         if (*argv) {
  71                 execvp(*argv, argv);
  72                 err(errno == ENOENT ? 127 : 126, "%s", *argv);
  73         }
  74         for (ep = environ; *ep; ep++)
  75                 printf("%s\n", *ep);
  76         exit(0);
  77 }
  78
  79 static void
  80 usage(void)
  81 {
  82         fprintf(stderr,
  83             "usage: env [-i] [name=value ...] [utility [argument ...]]\n");
  84         exit(1);
  85 }