1 /* $OpenBSD: dl_dirname.c,v 1.2 2015/01/16 16:18:07 deraadt 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/types.h> 20 #include <limits.h> 21 #include "archdep.h" 22 23 /* 24 * This file was copied from libc/stdlib/realpath.c and modified for ld.so's 25 * syscall method which returns -errno. 26 */ 27 28 char * 29 _dl_dirname(const char *path) 30 { 31 static char dname[PATH_MAX]; 32 size_t len; 33 const char *endp; 34 35 /* Empty or NULL string gets treated as "." */ 36 if (path == NULL || *path == '\0') { 37 dname[0] = '.'; 38 dname[1] = '\0'; 39 return (dname); 40 } 41 42 /* Strip any trailing slashes */ 43 endp = path + strlen(path) - 1; 44 while (endp > path && *endp == '/') 45 endp--; 46 47 /* Find the start of the dir */ 48 while (endp > path && *endp != '/') 49 endp--; 50 51 /* Either the dir is "/" or there are no slashes */ 52 if (endp == path) { 53 dname[0] = *endp == '/' ? '/' : '.'; 54 dname[1] = '\0'; 55 return (dname); 56 } else { 57 /* Move forward past the separating slashes */ 58 do { 59 endp--; 60 } while (endp > path && *endp == '/'); 61 } 62 63 len = endp - path + 1; 64 if (len >= sizeof(dname)) { 65 return (NULL); 66 } 67 _dl_bcopy(path, dname, len); 68 dname[len] = '\0'; 69 return (dname); 70 } 71