gen/FreeBSD/dirname.c

   1 /*      $OpenBSD: dirname.c,v 1.13 2005/08/08 08:05:33 espie 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/cdefs.h>
  20 __FBSDID("$FreeBSD: src/lib/libc/gen/dirname.c,v 1.8 2008/11/03 05:19:45 delphij Exp $");
  21
  22 #include <errno.h>
  23 #include <libgen.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <sys/param.h>
  27
  28 #if __DARWIN_UNIX03
  29 #define const /**/
  30 #endif
  31
  32 char *
  33 dirname(const char *path)
  34 {
  35         static char *dname = NULL;
  36         size_t len;
  37         const char *endp;
  38
  39         if (dname == NULL) {
  40                 dname = (char *)malloc(MAXPATHLEN);
  41                 if (dname == NULL)
  42                         return(NULL);
  43         }
  44
  45         /* Empty or NULL string gets treated as "." */
  46         if (path == NULL || *path == '\0') {
  47                 dname[0] = '.';
  48                 dname[1] = '\0';
  49                 return (dname);
  50         }
  51
  52         /* Strip any trailing slashes */
  53         endp = path + strlen(path) - 1;
  54         while (endp > path && *endp == '/')
  55                 endp--;
  56
  57         /* Find the start of the dir */
  58         while (endp > path && *endp != '/')
  59                 endp--;
  60
  61         /* Either the dir is "/" or there are no slashes */
  62         if (endp == path) {
  63                 dname[0] = *endp == '/' ? '/' : '.';
  64                 dname[1] = '\0';
  65                 return (dname);
  66         } else {
  67                 /* Move forward past the separating slashes */
  68                 do {
  69                         endp--;
  70                 } while (endp > path && *endp == '/');
  71         }
  72
  73         len = endp - path + 1;
  74         if (len >= MAXPATHLEN) {
  75                 errno = ENAMETOOLONG;
  76                 return (NULL);
  77         }
  78         memcpy(dname, path, len);
  79         dname[len] = '\0';
  80         return (dname);
  81 }