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 324124 2017-09-30 17:30:22Z jhb $");
32
33#include <sys/types.h>
34
35#include <err.h>
36#include <errno.h>
37#include <stdbool.h>
38#include <stdio.h>
39#include <stdlib.h>
40#include <sysexits.h>
41#include <unistd.h>
42
43#include "getconf.h"
44
45static void	do_allsys(void);
46static void	do_allpath(const char *path);
47static void	do_confstr(const char *name, int key);
48static void	do_sysconf(const char *name, int key);
49static void	do_pathconf(const char *name, int key, const char *path);
50
51static void
52usage(void)
53{
54	fprintf(stderr,
55"usage: getconf -a [pathname]\n"
56"       getconf [-v prog_env] system_var\n"
57"       getconf [-v prog_env] path_var pathname\n");
58	exit(EX_USAGE);
59}
60
61int
62main(int argc, char **argv)
63{
64	bool aflag;
65	int c, key, valid;
66	const char *name, *vflag, *alt_path;
67	intmax_t limitval;
68
69	aflag = false;
70	vflag = NULL;
71	while ((c = getopt(argc, argv, "av:")) != -1) {
72		switch (c) {
73		case 'a':
74			aflag = true;
75			break;
76		case 'v':
77			vflag = optarg;
78			break;
79
80		default:
81			usage();
82		}
83	}
84
85	if (aflag) {
86		if (vflag != NULL)
87			usage();
88		if (argv[optind] == NULL)
89			do_allsys();
90		else
91			do_allpath(argv[optind]);
92		return (0);
93	}
94
95	if ((name = argv[optind]) == NULL)
96		usage();
97
98	if (vflag != NULL) {
99		if ((valid = find_progenv(vflag, &alt_path)) == 0)
100			errx(EX_USAGE, "invalid programming environment %s",
101			     vflag);
102		if (valid > 0 && alt_path != NULL) {
103			if (argv[optind + 1] == NULL)
104				execl(alt_path, "getconf", argv[optind],
105				      (char *)NULL);
106			else
107				execl(alt_path, "getconf", argv[optind],
108				      argv[optind + 1], (char *)NULL);
109
110			err(EX_OSERR, "execl: %s", alt_path);
111		}
112		if (valid < 0)
113			errx(EX_UNAVAILABLE, "environment %s is not available",
114			     vflag);
115	}
116
117	if (argv[optind + 1] == NULL) { /* confstr or sysconf */
118		if ((valid = find_limit(name, &limitval)) != 0) {
119			if (valid > 0)
120				printf("%" PRIdMAX "\n", limitval);
121			else
122				printf("undefined\n");
123
124			return 0;
125		}
126		if ((valid = find_confstr(name, &key)) != 0) {
127			if (valid > 0)
128				do_confstr(name, key);
129			else
130				printf("undefined\n");
131		} else {
132			valid = find_sysconf(name, &key);
133			if (valid > 0) {
134				do_sysconf(name, key);
135			} else if (valid < 0) {
136				printf("undefined\n");
137			} else
138				errx(EX_USAGE,
139				     "no such configuration parameter `%s'",
140				     name);
141		}
142	} else {
143		valid = find_pathconf(name, &key);
144		if (valid != 0) {
145			if (valid > 0)
146				do_pathconf(name, key, argv[optind + 1]);
147			else
148				printf("undefined\n");
149		} else
150			errx(EX_USAGE,
151			     "no such path configuration parameter `%s'",
152			     name);
153	}
154	return 0;
155}
156
157static void
158do_onestr(const char *name, int key)
159{
160	size_t len;
161
162	errno = 0;
163	len = confstr(key, 0, 0);
164	if (len == 0 && errno != 0) {
165		warn("confstr: %s", name);
166		return;
167	}
168	printf("%s: ", name);
169	if (len == 0)
170		printf("undefined\n");
171	else {
172		char buf[len + 1];
173
174		confstr(key, buf, len);
175		printf("%s\n", buf);
176	}
177}
178
179static void
180do_onesys(const char *name, int key)
181{
182	long value;
183
184	errno = 0;
185	value = sysconf(key);
186	if (value == -1 && errno != 0) {
187		warn("sysconf: %s", name);
188		return;
189	}
190	printf("%s: ", name);
191	if (value == -1)
192		printf("undefined\n");
193	else
194		printf("%ld\n", value);
195}
196
197static void
198do_allsys(void)
199{
200
201	foreach_confstr(do_onestr);
202	foreach_sysconf(do_onesys);
203}
204
205static void
206do_onepath(const char *name, int key, const char *path)
207{
208	long value;
209
210	errno = 0;
211	value = pathconf(path, key);
212	if (value == -1 && errno != EINVAL && errno != 0)
213		warn("pathconf: %s", name);
214	printf("%s: ", name);
215	if (value == -1)
216		printf("undefined\n");
217	else
218		printf("%ld\n", value);
219}
220
221static void
222do_allpath(const char *path)
223{
224
225	foreach_pathconf(do_onepath, path);
226}
227
228static void
229do_confstr(const char *name, int key)
230{
231	size_t len;
232	int savederr;
233
234	savederr = errno;
235	errno = 0;
236	len = confstr(key, 0, 0);
237	if (len == 0) {
238		if (errno)
239			err(EX_OSERR, "confstr: %s", name);
240		else
241			printf("undefined\n");
242	} else {
243		char buf[len + 1];
244
245		confstr(key, buf, len);
246		printf("%s\n", buf);
247	}
248	errno = savederr;
249}
250
251static void
252do_sysconf(const char *name, int key)
253{
254	long value;
255
256	errno = 0;
257	value = sysconf(key);
258	if (value == -1 && errno != 0)
259		err(EX_OSERR, "sysconf: %s", name);
260	else if (value == -1)
261		printf("undefined\n");
262	else
263		printf("%ld\n", value);
264}
265
266static void
267do_pathconf(const char *name, int key, const char *path)
268{
269	long value;
270
271	errno = 0;
272	value = pathconf(path, key);
273	if (value == -1 && errno != 0)
274		err(EX_OSERR, "pathconf: %s", name);
275	else if (value == -1)
276		printf("undefined\n");
277	else
278		printf("%ld\n", value);
279}
280
281