gnu/dist/gettext/gettext-tools/lib/c-strcasecmp.c

   1 /* c-strcasecmp.c -- case insensitive string comparator in C locale
   2    Copyright (C) 1998, 1999, 2005 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 /* Specification.  */
  23 #include "c-strcase.h"
  24
  25 #include "c-ctype.h"
  26
  27 int
  28 c_strcasecmp (const char *s1, const char *s2)
  29 {
  30   register const unsigned char *p1 = (const unsigned char *) s1;
  31   register const unsigned char *p2 = (const unsigned char *) s2;
  32   unsigned char c1, c2;
  33
  34   if (p1 == p2)
  35     return 0;
  36
  37   do
  38     {
  39       c1 = c_tolower (*p1);
  40       c2 = c_tolower (*p2);
  41
  42       if (c1 == '\0')
  43         break;
  44
  45       ++p1;
  46       ++p2;
  47     }
  48   while (c1 == c2);
  49
  50   return c1 - c2;
  51 }