/* c-strncasecmp.c -- case insensitive string comparator in C locale
  Copyright (C) 1998-1999, 2005-2006 Free Software Foundation, Inc.

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2, or (at your option)
  any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software Foundation,
  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

#include <config.h>

/* Specification.  */
#include "c-strcase.h"

#include <limits.h>

#include "c-ctype.h"

int
c_strncasecmp (const char *s1, const char *s2, size_t n)
{
 register const unsigned char *p1 = (const unsigned char *) s1;
 register const unsigned char *p2 = (const unsigned char *) s2;
 unsigned char c1, c2;

 if (p1 == p2 || n == 0)
   return 0;

 do
   {
     c1 = c_tolower (*p1);
     c2 = c_tolower (*p2);

     if (--n == 0 || c1 == '\0')
       break;

     ++p1;
     ++p2;
   }
 while (c1 == c2);

 if (UCHAR_MAX <= INT_MAX)
   return c1 - c2;
 else
   /* On machines where 'char' and 'int' are types of the same size, the
      difference of two 'unsigned char' values - including the sign bit -
      doesn't fit in an 'int'.  */
   return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0);
}