题目: 输入一个字符串,同时输入帧头和帧尾(可以是多个字符),将该字符串中合法的帧识别出来.
提示:帧头和帧尾分别是head和tail 字符串”asdheadhauboisoktail”中headhauboisoktail是合法帧

#include <stdio.h>
#include <string.h>
#include <stdlib.h>char* p = NULL;
// 在字符串str中寻找字符串sub，如果找到返回从sub开始的字符串
char *findStr(char* str, char *sub)
{int len = strlen(sub);  // 算字串的长度while(*str){if (strncmp(str, sub, len) == 0){p = str;break;}str++;      }return p;
}// 找合法帧
void findFrame(char *str, char *head, char *tail)
{   char *phead = findStr(str, head);  // 找帧头的位置if (phead == NULL){printf ("帧头不存在");exit(0);}char *ptail = findStr(phead, tail);  // 找帧尾的位置if (ptail == NULL){printf ("帧尾不存在");exit(0);}ptail += strlen(tail);*ptail = '\0';printf ("%s\n", phead);} int main()
{char str[] = "atailsdheadhauboieadsoktailgdg";findFrame(str, "head", "tail");return 0;
}