printenv.c revision 92921 
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 const 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#if 0
41#ifndef lint
42static char sccsid[] = "@(#)printenv.c	8.2 (Berkeley) 5/4/95";
43#endif /* not lint */
44#endif
45
46#include <sys/cdefs.h>
47__FBSDID("$FreeBSD: head/usr.bin/printenv/printenv.c 92921 2002-03-22 01:33:25Z imp $");
48
49#include <sys/types.h>
50
51#include <stdlib.h>
52#include <stdio.h>
53#include <string.h>
54#include <unistd.h>
55
56void	usage(void);
57
58/*
59 * printenv
60 *
61 * Bill Joy, UCB
62 * February, 1979
63 */
64int
65main(argc, argv)
66	int argc;
67	char *argv[];
68{
69	extern char **environ;
70	register char *cp, **ep;
71	register size_t len;
72	int ch;
73
74	while ((ch = getopt(argc, argv, "")) != -1)
75		switch(ch) {
76		case '?':
77		default:
78			usage();
79		}
80	argc -= optind;
81	argv += optind;
82
83	if (argc == 0) {
84		for (ep = environ; *ep; ep++)
85			(void)printf("%s\n", *ep);
86		exit(0);
87	}
88	len = strlen(*argv);
89	for (ep = environ; *ep; ep++)
90		if (!memcmp(*ep, *argv, len)) {
91			cp = *ep + len;
92			if (!*cp || *cp == '=') {
93				(void)printf("%s\n", *cp ? cp + 1 : cp);
94				exit(0);
95			}
96		}
97	exit(1);
98}
99
100void
101usage()
102{
103	(void)fprintf(stderr, "usage: printenv [name]\n");
104	exit(1);
105}
106