lib/basename.c

   1 /* basename.c -- return the last element in a path
   2    Copyright (C) 1990, 1998, 1999, 2000, 2001 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 #include <stdio.h>
  23 #include <assert.h>
  24
  25 #ifndef FILESYSTEM_PREFIX_LEN
  26 # define FILESYSTEM_PREFIX_LEN(Filename) 0
  27 #endif
  28
  29 #ifndef PARAMS
  30 # if defined PROTOTYPES || (defined __STDC__ && __STDC__)
  31 #  define PARAMS(Args) Args
  32 # else
  33 #  define PARAMS(Args) ()
  34 # endif
  35 #endif
  36
  37 #ifndef ISSLASH
  38 # define ISSLASH(C) ((C) == '/')
  39 #endif
  40
  41 char *base_name PARAMS ((char const *name));
  42
  43 /* In general, we can't use the builtin `basename' function if available,
  44    since it has different meanings in different environments.
  45    In some environments the builtin `basename' modifies its argument.
  46    If NAME is all slashes, be sure to return `/'.  */
  47
  48 char *
  49 base_name (char const *name)
  50 {
  51   char const *base = name += FILESYSTEM_PREFIX_LEN (name);
  52   int all_slashes = 1;
  53   char const *p;
  54
  55   for (p = name; *p; p++)
  56     {
  57       if (ISSLASH (*p))
  58         base = p + 1;
  59       else
  60         all_slashes = 0;
  61     }
  62
  63   /* If NAME is all slashes, arrange to return `/'.  */
  64   if (*base == '\0' && ISSLASH (*name) && all_slashes)
  65     --base;
  66
  67   /* Make sure the last byte is not a slash.  */
  68   assert (all_slashes || !ISSLASH (*(p - 1)));
  69
  70   return (char *) base;
  71 }