1 /* $NetBSD: dirname.c,v 1.13 2014/07/16 10:52:26 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1997, 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Klaus Klein and Jason R. Thorpe. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 __RCSID("$NetBSD: dirname.c,v 1.13 2014/07/16 10:52:26 christos Exp $"); 35 #endif /* !LIBC_SCCS && !lint */ 36 37 #include "namespace.h" 38 #include <sys/param.h> 39 #include <libgen.h> 40 #include <limits.h> 41 #include <string.h> 42 43 #ifdef __weak_alias 44 __weak_alias(dirname,_dirname) 45 #endif 46 47 static size_t 48 xdirname_r(const char *path, char *buf, size_t buflen) 49 { 50 const char *endp; 51 size_t len; 52 53 /* 54 * If `path' is a null pointer or points to an empty string, 55 * return a pointer to the string ".". 56 */ 57 if (path == NULL || *path == '\0') { 58 path = "."; 59 len = 1; 60 goto out; 61 } 62 63 /* Strip trailing slashes, if any. */ 64 endp = path + strlen(path) - 1; 65 while (endp != path && *endp == '/') 66 endp--; 67 68 /* Find the start of the dir */ 69 while (endp > path && *endp != '/') 70 endp--; 71 72 if (endp == path) { 73 path = *endp == '/' ? "/" : "."; 74 len = 1; 75 goto out; 76 } 77 78 do 79 endp--; 80 while (endp > path && *endp == '/'); 81 82 len = endp - path + 1; 83 out: 84 if (buf != NULL && buflen != 0) { 85 buflen = MIN(len, buflen - 1); 86 memcpy(buf, path, buflen); 87 buf[buflen] = '\0'; 88 } 89 return len; 90 } 91 92 #if !HAVE_DIRNAME 93 char * 94 dirname(char *path) 95 { 96 static char result[PATH_MAX]; 97 (void)xdirname_r(path, result, sizeof(result)); 98 return result; 99 } 100 #endif 101