compat/dirname.c

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