/* strcasestr.c - Find if one string appears as a substring of another string,		  without regard to case. *//* Copyright (C) 2000 Free Software Foundation, Inc.   This file is part of GNU Bash, the Bourne Again SHell.   Bash 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 3 of the License, or   (at your option) any later version.   Bash 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 Bash.  If not, see <http://www.gnu.org/licenses/>.*/#include <config.h>#include <bashansi.h>#include <chartypes.h>#include <stdc.h>/* Determine if s2 occurs in s1.  If so, return a pointer to the   match in s1.  The compare is case insensitive.  This is a   case-insensitive strstr(3). */char *strcasestr (s1, s2)     const char *s1;     const char *s2;{  register int i, l, len, c;  c = TOLOWER ((unsigned char)s2[0]);  len = strlen (s1);  l = strlen (s2);  for (i = 0; (len - i) >= l; i++)    if ((TOLOWER ((unsigned char)s1[i]) == c) && (strncasecmp (s1 + i, s2, l) == 0))      return ((char *)s1 + i);  return ((char *)0);}