printenv.c revision 1590 
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	8.1 (Berkeley) 6/6/93";
42#endif /* not lint */
43
44#include <sys/types.h>
45
46#include <stdlib.h>
47#include <stdio.h>
48#include <string.h>
49
50void	usage __P((void));
51
52/*
53 * printenv
54 *
55 * Bill Joy, UCB
56 * February, 1979
57 */
58int
59main(argc, argv)
60	int argc;
61	char *argv[];
62{
63	extern char **environ;
64	register char *cp, **ep;
65	register size_t len;
66	int ch;
67
68	while ((ch = getopt(argc, argv, "")) != EOF)
69		switch(ch) {
70		case '?':
71		default:
72			usage();
73		}
74	argc -= optind;
75	argv += optind;
76
77	if (argc == 0) {
78		for (ep = environ; *ep; ep++)
79			(void)printf("%s\n", *ep);
80		exit(0);
81	}
82	len = strlen(*argv);
83	for (ep = environ; *ep; ep++)
84		if (!memcmp(*ep, *argv, len)) {
85			cp = *ep + len;
86			if (!*cp || *cp == '=') {
87				(void)printf("%s\n", *cp ? cp + 1 : cp);
88				exit(0);
89			}
90		}
91	exit(1);
92}
93
94void
95usage()
96{
97	(void)fprintf(stderr, "usage: printenv [name]\n");
98	exit(1);
99}
100