xref: /freebsd/usr.bin/getconf/getconf.c (revision 814aaaa7da4dab462d90e12e7b48b75f2093ccfd)
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("$FreeBSD$");
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 
44 static void	do_confstr(const char *name, int key);
45 static void	do_sysconf(const char *name, int key);
46 static void	do_pathconf(const char *name, int key, const char *path);
47 
48 static void
49 usage(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 
57 int
58 main(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 
138 static void
139 do_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 
161 static void
162 do_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 
176 static void
177 do_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