xref: /dragonfly/usr.bin/getconf/getconf.c (revision ed36d35d)
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  * $FreeBSD: head/usr.bin/getconf/getconf.c 164945 2006-12-06 12:00:26Z maxim $
30  */
31 
32 #include <sys/types.h>
33 
34 #include <err.h>
35 #include <errno.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <sysexits.h>
39 #include <unistd.h>
40 
41 #include "getconf.h"
42 
43 static void	do_confstr(const char *name, int key);
44 static void	do_sysconf(const char *name, int key);
45 static void	do_pathconf(const char *name, int key, const char *path);
46 
47 static void
48 usage(void)
49 {
50 	fprintf(stderr,
51 "usage: getconf [-v prog_env] system_var\n"
52 "       getconf [-v prog_env] path_var pathname\n");
53 	exit(EX_USAGE);
54 }
55 
56 int
57 main(int argc, char **argv)
58 {
59 	int c, key, valid;
60 	const char *name, *vflag, *alt_path;
61 	intmax_t limitval;
62 
63 	vflag = NULL;
64 	while ((c = getopt(argc, argv, "v:")) != -1) {
65 		switch (c) {
66 		case 'v':
67 			vflag = optarg;
68 			break;
69 
70 		default:
71 			usage();
72 		}
73 	}
74 
75 	if ((name = argv[optind]) == NULL)
76 		usage();
77 
78 	if (vflag != NULL) {
79 		if ((valid = find_progenv(vflag, &alt_path)) == 0)
80 			errx(EX_USAGE, "invalid programming environment %s",
81 			     vflag);
82 		if (valid > 0 && alt_path != NULL) {
83 			if (argv[optind + 1] == NULL)
84 				execl(alt_path, "getconf", argv[optind],
85 				      NULL);
86 			else
87 				execl(alt_path, "getconf", argv[optind],
88 				      argv[optind + 1], NULL);
89 
90 			err(EX_OSERR, "execl: %s", alt_path);
91 		}
92 		if (valid < 0)
93 			errx(EX_UNAVAILABLE, "environment %s is not available",
94 			     vflag);
95 	}
96 
97 	if (argv[optind + 1] == NULL) { /* confstr or sysconf */
98 		if ((valid = find_limit(name, &limitval)) != 0) {
99 			if (valid > 0)
100 				printf("%" PRIdMAX "\n", limitval);
101 			else
102 				printf("undefined\n");
103 
104 			return 0;
105 		}
106 		if ((valid = find_confstr(name, &key)) != 0) {
107 			if (valid > 0)
108 				do_confstr(name, key);
109 			else
110 				printf("undefined\n");
111 		} else {
112 			valid = find_sysconf(name, &key);
113 			if (valid > 0) {
114 				do_sysconf(name, key);
115 			} else if (valid < 0) {
116 				printf("undefined\n");
117 			} else
118 				errx(EX_USAGE,
119 				     "no such configuration parameter `%s'",
120 				     name);
121 		}
122 	} else {
123 		valid = find_pathconf(name, &key);
124 		if (valid != 0) {
125 			if (valid > 0)
126 				do_pathconf(name, key, argv[optind + 1]);
127 			else
128 				printf("undefined\n");
129 		} else
130 			errx(EX_USAGE,
131 			     "no such path configuration parameter `%s'",
132 			     name);
133 	}
134 	return 0;
135 }
136 
137 static void
138 do_confstr(const char *name, int key)
139 {
140 	size_t len;
141 	int savederr;
142 
143 	savederr = errno;
144 	errno = 0;
145 	len = confstr(key, 0, 0);
146 	if (len == 0) {
147 		if (errno)
148 			err(EX_OSERR, "confstr: %s", name);
149 		else
150 			printf("undefined\n");
151 	} else {
152 		char buf[len + 1];
153 
154 		confstr(key, buf, len);
155 		printf("%s\n", buf);
156 	}
157 	errno = savederr;
158 }
159 
160 static void
161 do_sysconf(const char *name, int key)
162 {
163 	long value;
164 
165 	errno = 0;
166 	value = sysconf(key);
167 	if (value == -1 && errno != 0)
168 		err(EX_OSERR, "sysconf: %s", name);
169 	else if (value == -1)
170 		printf("undefined\n");
171 	else
172 		printf("%ld\n", value);
173 }
174 
175 static void
176 do_pathconf(const char *name, int key, const char *path)
177 {
178 	long value;
179 
180 	errno = 0;
181 	value = pathconf(path, key);
182 	if (value == -1 && errno != 0)
183 		err(EX_OSERR, "pathconf: %s", name);
184 	else if (value == -1)
185 		printf("undefined\n");
186 	else
187 		printf("%ld\n", value);
188 }
189 
190