1 /* $NetBSD: confstr.c,v 1.13 2012/06/25 22:32:43 abs Exp $ */
2
3 /*-
4 * Copyright (c) 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)confstr.c 8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: confstr.c,v 1.13 2012/06/25 22:32:43 abs Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40
41 #include "namespace.h"
42 #include <sys/param.h>
43 #include <sys/sysctl.h>
44
45 #include <errno.h>
46 #include <paths.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50
51 #ifdef __weak_alias
__weak_alias(confstr,_confstr)52 __weak_alias(confstr,_confstr)
53 #endif
54
55 size_t
56 confstr(int name, char *buf, size_t len)
57 {
58 size_t tlen;
59 int mib[2], sverrno;
60 char *p;
61
62 /*
63 * POSIX 1003.2 requires errors to return 0 --
64 * that is *really* useful.
65 */
66 switch (name) {
67 case _CS_PATH:
68 mib[0] = CTL_USER;
69 mib[1] = USER_CS_PATH;
70 if (sysctl(mib, 2, NULL, &tlen, NULL, 0) == -1)
71 return 0;
72 if (len != 0 && buf != NULL) {
73 if ((p = malloc(tlen)) == NULL)
74 return 0;
75 if (sysctl(mib, 2, p, &tlen, NULL, 0) == -1) {
76 sverrno = errno;
77 free(p);
78 errno = sverrno;
79 return 0;
80 }
81 /*
82 * POSIX 1003.2 requires partial return of
83 * the string -- that is even more useful.
84 */
85 (void)strncpy(buf, p, len - 1);
86 buf[len - 1] = '\0';
87 free(p);
88 }
89 return tlen + 1;
90 default:
91 errno = EINVAL;
92 return 0;
93 }
94 /* NOTREACHED */
95 }
96