openbsd-compat/dirname.c

   1 /* OPENBSD ORIGINAL: lib/libc/gen/dirname.c */
   2
   3 /*      $OpenBSD: dirname.c,v 1.10 2003/06/17 21:56:23 millert Exp $    */
   4
   5 /*
   6  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
   7  *
   8  * Permission to use, copy, modify, and distribute this software for any
   9  * purpose with or without fee is hereby granted, provided that the above
  10  * copyright notice and this permission notice appear in all copies.
  11  *
  12  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  13  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  14  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  15  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  16  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  17  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  18  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  19  */
  20
  21 #include "includes.h"
  22 #ifndef HAVE_DIRNAME
  23
  24 #ifndef lint
  25 static char rcsid[] = "$OpenBSD: dirname.c,v 1.10 2003/06/17 21:56:23 millert Exp $";
  26 #endif /* not lint */
  27
  28 #include <errno.h>
  29 #include <string.h>
  30 #include <sys/param.h>
  31
  32 char *
  33 dirname(const char *path)
  34 {
  35         static char bname[MAXPATHLEN];
  36         register const char *endp;
  37
  38         /* Empty or NULL string gets treated as "." */
  39         if (path == NULL || *path == '\0') {
  40                 (void)strlcpy(bname, ".", sizeof bname);
  41                 return(bname);
  42         }
  43
  44         /* Strip trailing slashes */
  45         endp = path + strlen(path) - 1;
  46         while (endp > path && *endp == '/')
  47                 endp--;
  48
  49         /* Find the start of the dir */
  50         while (endp > path && *endp != '/')
  51                 endp--;
  52
  53         /* Either the dir is "/" or there are no slashes */
  54         if (endp == path) {
  55                 (void)strlcpy(bname, *endp == '/' ? "/" : ".", sizeof bname);
  56                 return(bname);
  57         } else {
  58                 do {
  59                         endp--;
  60                 } while (endp > path && *endp == '/');
  61         }
  62
  63         if (endp - path + 2 > sizeof(bname)) {
  64                 errno = ENAMETOOLONG;
  65                 return(NULL);
  66         }
  67         strlcpy(bname, path, endp - path + 2);
  68         return(bname);
  69 }
  70 #endif