printenv/printenv.c

   1 /*      $NetBSD: printenv.c,v 1.6 1997/10/19 12:44:26 lukem Exp $       */
   2
   3 /*
   4  * Copyright (c) 1987, 1993
   5  *    Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 #ifndef lint
  38 __COPYRIGHT("@(#) Copyright (c) 1987, 1993\n\
  39       The Regents of the University of California.  All rights reserved.\n");
  40 #endif /* not lint */
  41
  42 #ifndef lint
  43 /*static char sccsid[] = "from: @(#)printenv.c  8.2 (Berkeley) 5/4/95";*/
  44 __RCSID("$NetBSD: printenv.c,v 1.6 1997/10/19 12:44:26 lukem Exp $");
  45 #endif /* not lint */
  46
  47 #include <sys/types.h>
  48
  49 #include <stdlib.h>
  50 #include <stdio.h>
  51 #include <string.h>
  52 #include <unistd.h>
  53
  54 int     main __P((int, char **));
  55 void    usage __P((void));
  56
  57 /*
  58  * printenv
  59  *
  60  * Bill Joy, UCB
  61  * February, 1979
  62  */
  63 int
  64 main(argc, argv)
  65         int argc;
  66         char *argv[];
  67 {
  68         extern char **environ;
  69         char *cp, **ep;
  70         size_t len;
  71         int ch;
  72
  73         while ((ch = getopt(argc, argv, "")) != -1)
  74                 switch(ch) {
  75                 case '?':
  76                 default:
  77                         usage();
  78                 }
  79         argc -= optind;
  80         argv += optind;
  81
  82         if (argc == 0) {
  83                 for (ep = environ; *ep; ep++)
  84                         (void)printf("%s\n", *ep);
  85                 exit(0);
  86         }
  87         len = strlen(*argv);
  88         for (ep = environ; *ep; ep++)
  89                 if (!memcmp(*ep, *argv, len)) {
  90                         cp = *ep + len;
  91                         if (!*cp || *cp == '=') {
  92                                 (void)printf("%s\n", *cp ? cp + 1 : cp);
  93                                 exit(0);
  94                         }
  95                 }
  96         exit(1);
  97 }
  98
  99 void
 100 usage()
 101 {
 102         (void)fprintf(stderr, "usage: printenv [name]\n");
 103         exit(1);
 104 }