/* Copyright (C) 1994, 1999 Free Software Foundation, Inc.This file is part of the GNU C Library.This program is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2, or (at your option)any later version.This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with this program; if not, write to the Free SoftwareFoundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  *//* * My personal strstr() implementation that beats most other algorithms. * Until someone tells me otherwise, I assume that this is the * fastest implementation of strstr() in C. * I deliberately chose not to comment it.  You should have at least * as much fun trying to understand it, as I had to write it :-). * * Stephen R. van den Berg, berg@pool.informatik.rwth-aachen.de	*/#if HAVE_CONFIG_H# include <config.h>#endif#if defined _LIBC || defined HAVE_STRING_H# include <string.h>#endif#include <sys/types.h>typedef unsigned chartype;#undef strstrchar *strstr (const char *phaystack, const char *pneedle){  register const unsigned char *haystack, *needle;  register chartype b, c;  haystack = (const unsigned char *) phaystack;  needle = (const unsigned char *) pneedle;  b = *needle;  if (b != '\0')    {      haystack--;				/* possible ANSI violation */      do	{	  c = *++haystack;	  if (c == '\0')	    goto ret0;	}      while (c != b);      c = *++needle;      if (c == '\0')	goto foundneedle;      ++needle;      goto jin;      for (;;)        {          register chartype a;	  register const unsigned char *rhaystack, *rneedle;	  do	    {	      a = *++haystack;	      if (a == '\0')		goto ret0;	      if (a == b)		break;	      a = *++haystack;	      if (a == '\0')		goto ret0;shloop:;    }          while (a != b);jin:	  a = *++haystack;	  if (a == '\0')	    goto ret0;	  if (a != c)	    goto shloop;	  rhaystack = haystack-- + 1;	  rneedle = needle;	  a = *rneedle;	  if (*rhaystack == a)	    do	      {		if (a == '\0')		  goto foundneedle;		++rhaystack;		a = *++needle;		if (*rhaystack != a)		  break;		if (a == '\0')		  goto foundneedle;		++rhaystack;		a = *++needle;	      }	    while (*rhaystack == a);	  needle = rneedle;		   /* took the register-poor approach */	  if (a == '\0')	    break;        }    }foundneedle:  return (char*) haystack;ret0:  return 0;}