xref: /netbsd-src/usr.bin/printenv/printenv.c (revision d0fed6c87ddc40a8bffa6f99e7433ddfc864dd83)
1 /*	$NetBSD: printenv.c,v 1.5 1997/01/09 15:17:32 tls 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 #ifndef lint
37 static char copyright[] =
38 "@(#) 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 static char rcsid[] = "$NetBSD: printenv.c,v 1.5 1997/01/09 15:17:32 tls 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 void  usage __P((void));
55 
56 /*
57  * printenv
58  *
59  * Bill Joy, UCB
60  * February, 1979
61  */
62 int
63 main(argc, argv)
64 	int argc;
65 	char *argv[];
66 {
67 	extern char **environ;
68 	char *cp, **ep;
69 	size_t len;
70 	int ch;
71 
72 	while ((ch = getopt(argc, argv, "")) != EOF)
73 		switch(ch) {
74 		case '?':
75 		default:
76 			usage();
77 		}
78 	argc -= optind;
79 	argv += optind;
80 
81 	if (argc == 0) {
82 		for (ep = environ; *ep; ep++)
83 			(void)printf("%s\n", *ep);
84 		exit(0);
85 	}
86 	len = strlen(*argv);
87 	for (ep = environ; *ep; ep++)
88 		if (!memcmp(*ep, *argv, len)) {
89 			cp = *ep + len;
90 			if (!*cp || *cp == '=') {
91 				(void)printf("%s\n", *cp ? cp + 1 : cp);
92 				exit(0);
93 			}
94 		}
95 	exit(1);
96 }
97 
98 void
99 usage()
100 {
101 	(void)fprintf(stderr, "usage: printenv [name]\n");
102 	exit(1);
103 }
104