printenv.c revision 332463 
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 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#ifndef lint
31static const char copyright[] =
32"@(#) Copyright (c) 1987, 1993\n\
33	The Regents of the University of California.  All rights reserved.\n";
34#endif /* not lint */
35
36#if 0
37#ifndef lint
38static char sccsid[] = "@(#)printenv.c	8.2 (Berkeley) 5/4/95";
39#endif /* not lint */
40#endif
41
42#include <sys/cdefs.h>
43__FBSDID("$FreeBSD: stable/11/usr.bin/printenv/printenv.c 332463 2018-04-13 03:30:10Z kevans $");
44
45#include <sys/types.h>
46
47#include <capsicum_helpers.h>
48#include <err.h>
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	if (caph_limit_stdio() < 0 || (cap_enter() < 0 && errno != ENOSYS))
71		err(1, "capsicum");
72
73	while ((ch = getopt(argc, argv, "")) != -1)
74		switch(ch) {
75		case '?':
76		default:
77			usage();
78		}
79	argc -= optind;
80	argv += optind;
81
82	if (argc == 0) {
83		for (ep = environ; *ep; ep++)
84			(void)printf("%s\n", *ep);
85		exit(0);
86	}
87	len = strlen(*argv);
88	for (ep = environ; *ep; ep++)
89		if (!memcmp(*ep, *argv, len)) {
90			cp = *ep + len;
91			if (*cp == '=') {
92				(void)printf("%s\n", cp + 1);
93				exit(0);
94			}
95		}
96	exit(1);
97}
98
99void
100usage(void)
101{
102	(void)fprintf(stderr, "usage: printenv [name]\n");
103	exit(1);
104}
105