lib/dirname.c

   1 /* dirname.c -- return all but the last element in a path
   2    Copyright (C) 1990 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
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17
  18 #ifdef HAVE_CONFIG_H
  19 #if defined (CONFIG_BROKETS)
  20 /* We use <config.h> instead of "config.h" so that a compilation
  21    using -I. -I will use ./config.h rather than /config.h
  22    (which it would do because it found this file in ).  */
  23 #include <config.h>
  24 #else
  25 #include "config.h"
  26 #endif
  27 #endif
  28
  29 #ifdef STDC_HEADERS
  30 #include <stdlib.h>
  31 #else
  32 char *malloc ();
  33 #endif
  34 #if defined(STDC_HEADERS) || defined(HAVE_STRING_H)
  35 #include <string.h>
  36 #ifndef rindex
  37 #define rindex strrchr
  38 #endif
  39 #else
  40 #include <strings.h>
  41 #endif
  42
  43 /* Return the leading directories part of PATH,
  44    allocated with malloc.  If out of memory, return 0.
  45    Assumes that trailing slashes have already been
  46    removed.  */
  47
  48 char *
  49 dirname (path)
  50      char *path;
  51 {
  52   char *newpath;
  53   char *slash;
  54   int length;                   /* Length of result, not including NUL.  */
  55
  56   slash = rindex (path, '/');
  57   if (slash == 0)
  58     {
  59       /* File is in the current directory.  */
  60       path = ".";
  61       length = 1;
  62     }
  63   else
  64     {
  65       /* Remove any trailing slashes from the result.  */
  66       while (slash > path && *slash == '/')
  67         --slash;
  68
  69       length = slash - path + 1;
  70     }
  71   newpath = malloc (length + 1);
  72   if (newpath == 0)
  73     return 0;
  74   strncpy (newpath, path, length);
  75   newpath[length] = 0;
  76   return newpath;
  77 }