libiberty/filename_cmp.c

   1 /* File name comparison routine.
   2
   3    Copyright (C) 2007 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
  18
  19 #ifdef HAVE_STRING_H
  20 #include <string.h>
  21 #endif
  22
  23 #include <ctype.h>
  24 #include "filenames.h"
  25
  26 /*
  27
  28 @deftypefn Extension int filename_cmp (const char *@var{s1}, const char *@var{s2})
  29
  30 Return zero if the two paths @var{s1} and @var{s2} are equivalent.
  31 If not equivalent, the returned value is similar to what strcmp would
  32 return.  In other words, it returns a negative value if @var{s1} is less
  33 than @var{s2}, or a positive value if @var{s2} is greater than @var{s2}.
  34
  35 This function does not normalize path names. As a result, this function
  36 will treat filenames that are spelled differently as different even in
  37 the case when the two filenames point to the same underlying file.
  38 However, it does handle the fact that on DOS-like file systems, forward
  39 and backward slashes are equal.
  40
  41 @end deftypefn
  42
  43 */
  44
  45 int
  46 filename_cmp (const char *s1, const char *s2)
  47 {
  48 #ifndef HAVE_DOS_BASED_FILE_SYSTEM
  49   return strcmp(s1, s2);
  50 #else
  51   for (;;)
  52     {
  53       int c1 = tolower (*s1);
  54       int c2 = tolower (*s2);
  55
  56       /* On DOS-based file systems, the '/' and the '\' are equivalent.  */
  57       if (c1 == '/')
  58         c1 = '\\';
  59       if (c2 == '/')
  60         c2 = '\\';
  61
  62       if (c1 != c2)
  63         return (c1 - c2);
  64
  65       if (c1 == '\0')
  66         return 0;
  67
  68       s1++;
  69       s2++;
  70     }
  71 #endif
  72 }
  73