string/strcasecmp.c

   1 /* Copyright (C) 1991,1992,1995,1996,1997,2001,2002, 2004
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #include <ctype.h>
  25 #include <string.h>
  26
  27 #ifndef _LIBC
  28 # define __strcasecmp strcasecmp
  29 # define TOLOWER(Ch) tolower (Ch)
  30 #else
  31 # include <locale/localeinfo.h>
  32 # ifdef USE_IN_EXTENDED_LOCALE_MODEL
  33 #  define __strcasecmp __strcasecmp_l
  34 # endif
  35 # define TOLOWER(Ch) __tolower_l ((Ch), loc)
  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 #if defined _LIBC && !defined USE_IN_EXTENDED_LOCALE_MODEL
  56   __locale_t loc = _NL_CURRENT_LOCALE;
  57 #endif
  58   const unsigned char *p1 = (const unsigned char *) s1;
  59   const unsigned char *p2 = (const unsigned char *) s2;
  60   int result;
  61
  62   if (p1 == p2)
  63     return 0;
  64
  65   while ((result = TOLOWER (*p1) - TOLOWER (*p2++)) == 0)
  66     if (*p1++ == '\0')
  67       break;
  68
  69   return result;
  70 }
  71 #ifndef __strcasecmp
  72 libc_hidden_def (__strcasecmp)
  73 weak_alias (__strcasecmp, strcasecmp)
  74 #endif