1/*	$NetBSD: printenv.c,v 1.12 2011/09/06 18:26:55 joerg 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\
35 The Regents of the University of California.  All rights reserved.");
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 1.12 2011/09/06 18:26:55 joerg 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#include <err.h>
50
51__dead static void usage(void);
52
53/*
54 * printenv
55 *
56 * Bill Joy, UCB
57 * February, 1979
58 */
59int
60main(int argc, char *argv[])
61{
62	extern char **environ;
63	char *cp, **ep;
64	size_t len;
65	int ch;
66
67	while ((ch = getopt(argc, argv, "")) != -1)
68		switch(ch) {
69		case '?':
70		default:
71			usage();
72		}
73	argc -= optind;
74	argv += optind;
75
76	if (argc == 0) {
77		for (ep = environ; *ep; ep++)
78			(void)printf("%s\n", *ep);
79		exit(0);
80	}
81	if (argc != 1)
82		usage();
83	if (strchr(*argv, '=') != NULL)
84		errx(1, "Invalid environment variable %s", *argv);
85	len = strlen(*argv);
86	for (ep = environ; *ep; ep++)
87		if (!memcmp(*ep, *argv, len)) {
88			cp = *ep + len;
89			if (!*cp || *cp == '=') {
90				(void)printf("%s\n", *cp ? cp + 1 : cp);
91				exit(0);
92			}
93		}
94	exit(1);
95}
96
97static void
98usage(void)
99{
100	(void)fprintf(stderr, "Usage: printenv [name]\n");
101	exit(1);
102}
103