printenv.c revision 23691 
1/*
2 * Copyright (c) 1987, 1993
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. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static char copyright[] =
36"@(#) Copyright (c) 1987, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41static char sccsid[] = "@(#)printenv.c	8.2 (Berkeley) 5/4/95";
42#endif /* not lint */
43
44#include <sys/types.h>
45
46#include <stdlib.h>
47#include <stdio.h>
48#include <string.h>
49#include <unistd.h>
50
51void	usage __P((void));
52
53/*
54 * printenv
55 *
56 * Bill Joy, UCB
57 * February, 1979
58 */
59int
60main(argc, argv)
61	int argc;
62	char *argv[];
63{
64	extern char **environ;
65	register char *cp, **ep;
66	register size_t len;
67	int ch;
68
69	while ((ch = getopt(argc, argv, "")) != EOF)
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
95void
96usage()
97{
98	(void)fprintf(stderr, "usage: printenv [name]\n");
99	exit(1);
100}
101