/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h> /* * Return pointer to first occurrence of s2 in s1, * 0 if none */char*strstr(char *s1, char *s2){	char *p, *pa, *pb;	int c0, c; 	c0 = *s2;	if(c0 == 0)		return s1;	s2++;	for(p=strchr(s1, c0); p; p=strchr(p+1, c0)) {		pa = p;		for(pb=s2;; pb++) {			c = *pb;			if(c == 0)				return p;			if(c != *++pa)				break;		}	}	return 0;}