lib/dirname.c

   1 /* dirname.c -- return all but the last element in a path
   2    Copyright (C) 1990, 1998 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 #if HAVE_CONFIG_H
  19 # include <config.h>
  20 #endif
  21
  22 #ifdef STDC_HEADERS
  23 # include <stdlib.h>
  24 #else
  25 char *malloc ();
  26 #endif
  27 #if defined STDC_HEADERS || defined HAVE_STRING_H
  28 # include <string.h>
  29 #else
  30 # include <strings.h>
  31 # ifndef strrchr
  32 #  define strrchr rindex
  33 # endif
  34 #endif
  35
  36 #include "dirname.h"
  37
  38 /* Return the leading directories part of PATH,
  39    allocated with malloc.  If out of memory, return 0.
  40    Assumes that trailing slashes have already been
  41    removed.  */
  42
  43 char *
  44 dir_name (const char *path)
  45 {
  46   char *newpath;
  47   char *slash;
  48   int length;                   /* Length of result, not including NUL.  */
  49
  50   slash = strrchr (path, '/');
  51   if (slash == 0)
  52     {
  53       /* File is in the current directory.  */
  54       path = ".";
  55       length = 1;
  56     }
  57   else
  58     {
  59       /* Remove any trailing slashes from the result.  */
  60 #ifdef MSDOS
  61       char *lim = (path[0] >= 'A' && path[0] <= 'z' && path[1] == ':')
  62                   ? path + 2 : path;
  63
  64       /* If canonicalized "d:/path", leave alone the root case "d:/".  */
  65       while (slash > lim && *slash == '/')
  66         --slash;
  67 #else
  68       while (slash > path && *slash == '/')
  69         --slash;
  70 #endif
  71
  72       length = slash - path + 1;
  73     }
  74   newpath = (char *) malloc (length + 1);
  75   if (newpath == 0)
  76     return 0;
  77   strncpy (newpath, path, length);
  78   newpath[length] = 0;
  79   return newpath;
  80 }