sysdeps/generic/strcasecmp.c

   1 /* Copyright (C) 1991, 1992, 1995, 1996, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library 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 GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 # include <config.h>
  21 #endif
  22
  23 #include <ctype.h>
  24 #include <string.h>
  25
  26 #ifndef weak_alias
  27 # define __strcasecmp strcasecmp
  28 # define TOLOWER(Ch) tolower (Ch)
  29 #else
  30 # ifdef USE_IN_EXTENDED_LOCALE_MODEL
  31 #  define __strcasecmp __strcasecmp_l
  32 #  define TOLOWER(Ch) __tolower_l ((Ch), loc)
  33 # else
  34 #  define TOLOWER(Ch) tolower (Ch)
  35 # endif
  36 #endif
  37
  38 #ifdef USE_IN_EXTENDED_LOCALE_MODEL
  39 # define LOCALE_PARAM , loc
  40 # define LOCALE_PARAM_DECL __locale_t loc;
  41 #else
  42 # define LOCALE_PARAM
  43 # define LOCALE_PARAM_DECL
  44 #endif
  45
  46 /* Compare S1 and S2, ignoring case, returning less than, equal to or
  47    greater than zero if S1 is lexicographically less than,
  48    equal to or greater than S2.  */
  49 int
  50 __strcasecmp (s1, s2 LOCALE_PARAM)
  51      const char *s1;
  52      const char *s2;
  53      LOCALE_PARAM_DECL
  54 {
  55   const unsigned char *p1 = (const unsigned char *) s1;
  56   const unsigned char *p2 = (const unsigned char *) s2;
  57   unsigned char c1, c2;
  58
  59   if (p1 == p2)
  60     return 0;
  61
  62   do
  63     {
  64       c1 = TOLOWER (*p1++);
  65       c2 = TOLOWER (*p2++);
  66       if (c1 == '\0')
  67         break;
  68     }
  69   while (c1 == c2);
  70
  71   return c1 - c2;
  72 }
  73 #ifndef __strcasecmp
  74 weak_alias (__strcasecmp, strcasecmp)
  75 #endif