my strstr 简单实现

#include <stdio.h>const char* my_strstr(const char* src,const char* sub){const char* bp;const char* sp;/* * 判断参数的有效性 * */if((src == NULL) || (sub == NULL))return src;/* * 遍历src字符串 * */while(*src){bp = src;sp = sub;do{/* * 如果到了sub字符串结束符的位置 * 表示找到了sub字符串 * */if(!*sp)return src;}while(*bp++ == *sp++);src += 1;}return NULL;}int main(int argc,char** argv){const char *r = my_strstr(argv[1],argv[2]);printf("%s\n",r);return 0;}