strstr在vc runtime 里的实现以及测试代码

#include "stdafx.h"#include <iostream>/****strstr.c - search for one string inside another** Copyright (c) Microsoft Corporation. All rights reserved.**Purpose:* defines strstr() - search for one string inside another********************************************************************************/char * __cdecl My_strstr (const char * str1,const char * str2){char *cp = (char *) str1;char *s1, *s2;if ( !*str2 )return((char *)str1);while (*cp){s1 = cp;s2 = (char *) str2;while ( *s1 && *s2 && !(*s1-*s2) )s1++, s2++;if (!*s2)return(cp);cp++;}return(NULL);}int _tmain(int argc, _TCHAR* argv[]){char *src_str = "abcdefgh";char *in_str = "def";char *tmp_p = My_strstr(src_str,in_str);if (tmp_p == NULL){std::cout<<"not find "<<in_str<<std::endl;}elsestd::cout<<"find it "<<tmp_p<<std::endl;system("pause");return 0;}