confstr.c revision 11659 
1/*-
2 * Copyright (c) 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#if defined(LIBC_SCCS) && !defined(lint)
35static char sccsid[] = "@(#)confstr.c	8.1 (Berkeley) 6/4/93";
36#endif /* LIBC_SCCS and not lint */
37
38#include <sys/param.h>
39#include <sys/sysctl.h>
40
41#include <errno.h>
42#include <paths.h>
43#include <stdlib.h>
44#include <unistd.h>
45#include <string.h>
46
47size_t
48confstr(name, buf, len)
49	int name;
50	char *buf;
51	size_t len;
52{
53	size_t tlen;
54	int mib[2], sverrno;
55	char *p;
56
57	switch (name) {
58	case _CS_PATH:
59		mib[0] = CTL_USER;
60		mib[1] = USER_CS_PATH;
61		if (sysctl(mib, 2, NULL, &tlen, NULL, 0) == -1)
62			return (-1);
63		if (len != 0 && buf != NULL) {
64			if ((p = malloc(tlen)) == NULL)
65				return (-1);
66			if (sysctl(mib, 2, p, &tlen, NULL, 0) == -1) {
67				sverrno = errno;
68				free(p);
69				errno = sverrno;
70				return (-1);
71			}
72			/*
73			 * POSIX 1003.2 requires partial return of
74			 * the string -- that should be *real* useful.
75			 */
76			(void)strncpy(buf, p, len - 1);
77			buf[len - 1] = '\0';
78			free(p);
79		}
80		return (tlen + 1);
81	default:
82		errno = EINVAL;
83		return (0);
84	}
85	/* NOTREACHED */
86}
87