1 /* 2 * Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/ 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 #include <errno.h> 26 #include <libgen.h> 27 #include <stdlib.h> 28 #include <string.h> 29 #include <sys/param.h> 30 31 char * 32 dirname(char *path) 33 { 34 char *end; 35 36 /* 37 * If path is a null pointer or points to an empty string, 38 * dirname() shall return a pointer to the string ".". 39 */ 40 if (path == NULL || *path == '\0') 41 return (__DECONST(char *, ".")); 42 43 /* Find end of last pathname component. */ 44 end = path + strlen(path); 45 while (end > path + 1 && end[-1] == '/') 46 --end; 47 48 /* Strip off the last pathname component. */ 49 while (end > path && end[-1] != '/') 50 --end; 51 52 /* 53 * If path does not contain a '/', then dirname() shall return a 54 * pointer to the string ".". 55 */ 56 if (end == path) { 57 path[0] = '.'; 58 path[1] = '\0'; 59 return (path); 60 } 61 62 /* 63 * Remove trailing slashes from the resulting directory name. Ensure 64 * that at least one character remains. 65 */ 66 while (end > path + 1 && end[-1] == '/') 67 --end; 68 69 /* Null terminate directory name and return it. */ 70 *end = '\0'; 71 return (path); 72 } 73