printenv.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 * 4. 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#ifndef lint
33static const char copyright[] =
34"@(#) Copyright (c) 1987, 1993\n\
35	The Regents of the University of California.  All rights reserved.\n";
36#endif /* not lint */
37
38#if 0
39#ifndef lint
40static char sccsid[] = "@(#)printenv.c	8.2 (Berkeley) 5/4/95";
41#endif /* not lint */
42#endif
43
44#include <sys/cdefs.h>
45__FBSDID("$FreeBSD: stable/11/usr.bin/printenv/printenv.c 330897 2018-03-14 03:19:51Z eadler $");
46
47#include <sys/types.h>
48
49#include <stdlib.h>
50#include <stdio.h>
51#include <string.h>
52#include <unistd.h>
53
54void	usage(void);
55extern char **environ;
56
57/*
58 * printenv
59 *
60 * Bill Joy, UCB
61 * February, 1979
62 */
63int
64main(int argc, char *argv[])
65{
66	char *cp, **ep;
67	size_t len;
68	int ch;
69
70	while ((ch = getopt(argc, argv, "")) != -1)
71		switch(ch) {
72		case '?':
73		default:
74			usage();
75		}
76	argc -= optind;
77	argv += optind;
78
79	if (argc == 0) {
80		for (ep = environ; *ep; ep++)
81			(void)printf("%s\n", *ep);
82		exit(0);
83	}
84	len = strlen(*argv);
85	for (ep = environ; *ep; ep++)
86		if (!memcmp(*ep, *argv, len)) {
87			cp = *ep + len;
88			if (*cp == '=') {
89				(void)printf("%s\n", cp + 1);
90				exit(0);
91			}
92		}
93	exit(1);
94}
95
96void
97usage(void)
98{
99	(void)fprintf(stderr, "usage: printenv [name]\n");
100	exit(1);
101}
102