/*      Id: compat_strcasestr.c,v 1.5 2020/06/15 01:37:15 schwarze Exp  */
/*      NetBSD: strcasestr.c,v 1.3 2005/11/29 03:12:00 christos Exp     */

/*-
* Copyright (c) 1990, 1993
*      The Regents of the University of California.  All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "config.h"

#include <sys/types.h>
#include <ctype.h>
#include <string.h>

#define __UNCONST(a)    ((void *)(unsigned long)(const void *)(a))

/*
* Find the first occurrence of find in s, ignore case.
*/
char *
strcasestr(const char *s, const char *find)
{
       char c, sc;
       size_t len;

       if ((c = *find++) != 0) {
               c = tolower((unsigned char)c);
               len = strlen(find);
               do {
                       do {
                               if ((sc = *s++) == 0)
                                       return (NULL);
                       } while ((char)tolower((unsigned char)sc) != c);
               } while (strncasecmp(s, find, len) != 0);
               s--;
       }
       return __UNCONST(s);
}