xref: /netbsd-src/usr.bin/printenv/printenv.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: printenv.c,v 1.8 2003/08/07 11:15:31 agc 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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1987, 1993\n\
35       The Regents of the University of California.  All rights reserved.\n");
36 #endif /* not lint */
37 
38 #ifndef lint
39 /*static char sccsid[] = "from: @(#)printenv.c	8.2 (Berkeley) 5/4/95";*/
40 __RCSID("$NetBSD: printenv.c,v 1.8 2003/08/07 11:15:31 agc Exp $");
41 #endif /* not lint */
42 
43 #include <sys/types.h>
44 
45 #include <stdlib.h>
46 #include <stdio.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 int	main __P((int, char **));
51 void	usage __P((void));
52 
53 /*
54  * printenv
55  *
56  * Bill Joy, UCB
57  * February, 1979
58  */
59 int
60 main(argc, argv)
61 	int argc;
62 	char *argv[];
63 {
64 	extern char **environ;
65 	char *cp, **ep;
66 	size_t len;
67 	int ch;
68 
69 	while ((ch = getopt(argc, argv, "")) != -1)
70 		switch(ch) {
71 		case '?':
72 		default:
73 			usage();
74 		}
75 	argc -= optind;
76 	argv += optind;
77 
78 	if (argc == 0) {
79 		for (ep = environ; *ep; ep++)
80 			(void)printf("%s\n", *ep);
81 		exit(0);
82 	}
83 	len = strlen(*argv);
84 	for (ep = environ; *ep; ep++)
85 		if (!memcmp(*ep, *argv, len)) {
86 			cp = *ep + len;
87 			if (!*cp || *cp == '=') {
88 				(void)printf("%s\n", *cp ? cp + 1 : cp);
89 				exit(0);
90 			}
91 		}
92 	exit(1);
93 }
94 
95 void
96 usage()
97 {
98 	(void)fprintf(stderr, "usage: printenv [name]\n");
99 	exit(1);
100 }
101