compat/strcasestr.c

   1 /*****************************************************************************
   2  * strcasestr.c: GNU strcasestr() replacement
   3  *****************************************************************************
   4  * Copyright © 2002-2011 VLC authors and VideoLAN
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #include <string.h>
  26 #include <ctype.h>
  27 #include <assert.h>
  28
  29 char *strcasestr (const char *psz_big, const char *psz_little)
  30 {
  31     char *p_pos = (char *)psz_big;
  32
  33     if( !*psz_little ) return p_pos;
  34
  35     while( *p_pos )
  36     {
  37         if( toupper( (unsigned char)*p_pos ) == toupper( (unsigned char)*psz_little ) )
  38         {
  39             char *cur1 = p_pos + 1;
  40             char *cur2 = (char *)psz_little + 1;
  41             while( *cur1 && *cur2
  42              && toupper( (unsigned char)*cur1 ) == toupper( (unsigned char)*cur2 ) )
  43             {
  44                 cur1++;
  45                 cur2++;
  46             }
  47             if( !*cur2 ) return p_pos;
  48         }
  49         p_pos++;
  50     }
  51     return NULL;
  52 }