gen/FreeBSD/dirname.c

   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
  30 static 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: src/lib/libc/gen/dirname.c,v 1.7 2002/12/30 01:41:14 marcel Exp $");
  35
  36 #include <errno.h>
  37 #include <libgen.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <sys/param.h>
  41
  42 char *
  43 dirname(path)
  44         const char *path;
  45 {
  46         static char *bname = NULL;
  47         const char *endp;
  48
  49         if (bname == NULL) {
  50                 bname = (char *)malloc(MAXPATHLEN);
  51                 if (bname == NULL)
  52                         return(NULL);
  53         }
  54
  55         /* Empty or NULL string gets treated as "." */
  56         if (path == NULL || *path == '\0') {
  57                 (void)strcpy(bname, ".");
  58                 return(bname);
  59         }
  60
  61         /* Strip trailing slashes */
  62         endp = path + strlen(path) - 1;
  63         while (endp > path && *endp == '/')
  64                 endp--;
  65
  66         /* Find the start of the dir */
  67         while (endp > path && *endp != '/')
  68                 endp--;
  69
  70         /* Either the dir is "/" or there are no slashes */
  71         if (endp == path) {
  72                 (void)strcpy(bname, *endp == '/' ? "/" : ".");
  73                 return(bname);
  74         } else {
  75                 do {
  76                         endp--;
  77                 } while (endp > path && *endp == '/');
  78         }
  79
  80         if (endp - path + 2 > MAXPATHLEN) {
  81                 errno = ENAMETOOLONG;
  82                 return(NULL);
  83         }
  84         (void)strncpy(bname, path, endp - path + 1);
  85         bname[endp - path + 1] = '\0';
  86         return(bname);
  87 }