getconf.c revision 305229 
1/*
2 * Copyright 2000 Massachusetts Institute of Technology
3 *
4 * Permission to use, copy, modify, and distribute this software and
5 * its documentation for any purpose and without fee is hereby
6 * granted, provided that both the above copyright notice and this
7 * permission notice appear in all copies, that both the above
8 * copyright notice and this permission notice appear in all
9 * supporting documentation, and that the name of M.I.T. not be used
10 * in advertising or publicity pertaining to distribution of the
11 * software without specific, written prior permission.  M.I.T. makes
12 * no representations about the suitability of this software for any
13 * purpose.  It is provided "as is" without express or implied
14 * warranty.
15 *
16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
23 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: stable/10/usr.bin/getconf/getconf.c 305229 2016-09-01 19:10:42Z ngie $");
32
33#include <sys/types.h>
34
35#include <err.h>
36#include <errno.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <sysexits.h>
40#include <unistd.h>
41
42#include "getconf.h"
43
44static void	do_confstr(const char *name, int key);
45static void	do_sysconf(const char *name, int key);
46static void	do_pathconf(const char *name, int key, const char *path);
47
48static void
49usage(void)
50{
51	fprintf(stderr,
52"usage: getconf [-v prog_env] system_var\n"
53"       getconf [-v prog_env] path_var pathname\n");
54	exit(EX_USAGE);
55}
56
57int
58main(int argc, char **argv)
59{
60	int c, key, valid;
61	const char *name, *vflag, *alt_path;
62	intmax_t limitval;
63
64	vflag = NULL;
65	while ((c = getopt(argc, argv, "v:")) != -1) {
66		switch (c) {
67		case 'v':
68			vflag = optarg;
69			break;
70
71		default:
72			usage();
73		}
74	}
75
76	if ((name = argv[optind]) == NULL)
77		usage();
78
79	if (vflag != NULL) {
80		if ((valid = find_progenv(vflag, &alt_path)) == 0)
81			errx(EX_USAGE, "invalid programming environment %s",
82			     vflag);
83		if (valid > 0 && alt_path != NULL) {
84			if (argv[optind + 1] == NULL)
85				execl(alt_path, "getconf", argv[optind],
86				      (char *)NULL);
87			else
88				execl(alt_path, "getconf", argv[optind],
89				      argv[optind + 1], (char *)NULL);
90
91			err(EX_OSERR, "execl: %s", alt_path);
92		}
93		if (valid < 0)
94			errx(EX_UNAVAILABLE, "environment %s is not available",
95			     vflag);
96	}
97
98	if (argv[optind + 1] == NULL) { /* confstr or sysconf */
99		if ((valid = find_limit(name, &limitval)) != 0) {
100			if (valid > 0)
101				printf("%" PRIdMAX "\n", limitval);
102			else
103				printf("undefined\n");
104
105			return 0;
106		}
107		if ((valid = find_confstr(name, &key)) != 0) {
108			if (valid > 0)
109				do_confstr(name, key);
110			else
111				printf("undefined\n");
112		} else {
113			valid = find_sysconf(name, &key);
114			if (valid > 0) {
115				do_sysconf(name, key);
116			} else if (valid < 0) {
117				printf("undefined\n");
118			} else
119				errx(EX_USAGE,
120				     "no such configuration parameter `%s'",
121				     name);
122		}
123	} else {
124		valid = find_pathconf(name, &key);
125		if (valid != 0) {
126			if (valid > 0)
127				do_pathconf(name, key, argv[optind + 1]);
128			else
129				printf("undefined\n");
130		} else
131			errx(EX_USAGE,
132			     "no such path configuration parameter `%s'",
133			     name);
134	}
135	return 0;
136}
137
138static void
139do_confstr(const char *name, int key)
140{
141	size_t len;
142	int savederr;
143
144	savederr = errno;
145	errno = 0;
146	len = confstr(key, 0, 0);
147	if (len == 0) {
148		if (errno)
149			err(EX_OSERR, "confstr: %s", name);
150		else
151			printf("undefined\n");
152	} else {
153		char buf[len + 1];
154
155		confstr(key, buf, len);
156		printf("%s\n", buf);
157	}
158	errno = savederr;
159}
160
161static void
162do_sysconf(const char *name, int key)
163{
164	long value;
165
166	errno = 0;
167	value = sysconf(key);
168	if (value == -1 && errno != 0)
169		err(EX_OSERR, "sysconf: %s", name);
170	else if (value == -1)
171		printf("undefined\n");
172	else
173		printf("%ld\n", value);
174}
175
176static void
177do_pathconf(const char *name, int key, const char *path)
178{
179	long value;
180
181	errno = 0;
182	value = pathconf(path, key);
183	if (value == -1 && errno != 0)
184		err(EX_OSERR, "pathconf: %s", name);
185	else if (value == -1)
186		printf("undefined\n");
187	else
188		printf("%ld\n", value);
189}
190
191