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printenv.c revision 1.7 
      1 /*	$NetBSD: printenv.c,v 1.7 1999/09/10 04:05:28 simonb Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1987, 1993
      5  *    The 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 1.7 1999/09/10 04:05:28 simonb 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 }
    105