dirname.c revision 108152
1/* 2 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 17 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 18 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 19 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28#if 0 29#ifndef lint 30static char rcsid[] = "$OpenBSD: dirname.c,v 1.4 1999/05/30 17:10:30 espie Exp $"; 31#endif /* not lint */ 32#endif 33#include <sys/cdefs.h> 34__FBSDID("$FreeBSD: head/lib/libc/gen/dirname.c 108152 2002-12-21 07:12:35Z bbraun $"); 35 36#include <errno.h> 37#include <libgen.h> 38#include <string.h> 39#include <sys/param.h> 40 41char * 42dirname(path) 43 const char *path; 44{ 45 static char *bname = NULL; 46 const char *endp; 47 48 if (bname == NULL) { 49 bname = (char *)malloc(MAXPATHLEN); 50 if (bname == NULL) 51 return(NULL); 52 } 53 54 /* Empty or NULL string gets treated as "." */ 55 if (path == NULL || *path == '\0') { 56 (void)strcpy(bname, "."); 57 return(bname); 58 } 59 60 /* Strip trailing slashes */ 61 endp = path + strlen(path) - 1; 62 while (endp > path && *endp == '/') 63 endp--; 64 65 /* Find the start of the dir */ 66 while (endp > path && *endp != '/') 67 endp--; 68 69 /* Either the dir is "/" or there are no slashes */ 70 if (endp == path) { 71 (void)strcpy(bname, *endp == '/' ? "/" : "."); 72 return(bname); 73 } else { 74 do { 75 endp--; 76 } while (endp > path && *endp == '/'); 77 } 78 79 if (endp - path + 2 > MAXPATHLEN) { 80 errno = ENAMETOOLONG; 81 return(NULL); 82 } 83 (void)strncpy(bname, path, endp - path + 1); 84 bname[endp - path + 1] = '\0'; 85 return(bname); 86} 87