1 /* $NetBSD: confstr.c,v 1.12 2006/12/03 00:39:19 christos 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 1.12 2006/12/03 00:39:19 christos 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 52 __weak_alias(confstr,_confstr) 53 #endif 54 55 size_t 56 confstr(name, buf, len) 57 int name; 58 char *buf; 59 size_t len; 60 { 61 size_t tlen; 62 int mib[2], sverrno; 63 char *p; 64 65 /* 66 * POSIX 1003.2 requires errors to return 0 -- 67 * that is *really* useful. 68 */ 69 switch (name) { 70 case _CS_PATH: 71 mib[0] = CTL_USER; 72 mib[1] = USER_CS_PATH; 73 if (sysctl(mib, 2, NULL, &tlen, NULL, 0) == -1) 74 return 0; 75 if (len != 0 && buf != NULL) { 76 if ((p = malloc(tlen)) == NULL) 77 return 0; 78 if (sysctl(mib, 2, p, &tlen, NULL, 0) == -1) { 79 sverrno = errno; 80 free(p); 81 errno = sverrno; 82 return 0; 83 } 84 /* 85 * POSIX 1003.2 requires partial return of 86 * the string -- that is even more useful. 87 */ 88 (void)strncpy(buf, p, len - 1); 89 buf[len - 1] = '\0'; 90 free(p); 91 } 92 return tlen + 1; 93 default: 94 errno = EINVAL; 95 return 0; 96 } 97 /* NOTREACHED */ 98 } 99