1 /* $OpenBSD: dirname.c,v 1.13 2005/08/08 08:05:33 espie Exp $ */ 2 3 /* 4 * Copyright (c) 1997, 2004 Todd C. Miller <Todd.Miller@courtesan.com> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/cdefs.h> 20 __FBSDID("$FreeBSD$"); 21 22 #include <errno.h> 23 #include <libgen.h> 24 #include <stdlib.h> 25 #include <string.h> 26 #include <sys/param.h> 27 28 char * 29 dirname(const char *path) 30 { 31 static char *dname = NULL; 32 size_t len; 33 const char *endp; 34 35 if (dname == NULL) { 36 dname = (char *)malloc(MAXPATHLEN); 37 if (dname == NULL) 38 return(NULL); 39 } 40 41 /* Empty or NULL string gets treated as "." */ 42 if (path == NULL || *path == '\0') { 43 dname[0] = '.'; 44 dname[1] = '\0'; 45 return (dname); 46 } 47 48 /* Strip any trailing slashes */ 49 endp = path + strlen(path) - 1; 50 while (endp > path && *endp == '/') 51 endp--; 52 53 /* Find the start of the dir */ 54 while (endp > path && *endp != '/') 55 endp--; 56 57 /* Either the dir is "/" or there are no slashes */ 58 if (endp == path) { 59 dname[0] = *endp == '/' ? '/' : '.'; 60 dname[1] = '\0'; 61 return (dname); 62 } else { 63 /* Move forward past the separating slashes */ 64 do { 65 endp--; 66 } while (endp > path && *endp == '/'); 67 } 68 69 len = endp - path + 1; 70 if (len >= MAXPATHLEN) { 71 errno = ENAMETOOLONG; 72 return (NULL); 73 } 74 memcpy(dname, path, len); 75 dname[len] = '\0'; 76 return (dname); 77 } 78