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。
程序如下：
#include <stdio.h>
#include <string.h>
char *findstr(char *str, char *sub)
{
char *p = NULL;
int len = strlen(sub);
while(*str)
{
if(strncmp(str, sub, len) == 0)
{
p = str;
break;
}
str++;
}
return p;
}
void findframe(char *str, char *head, char *tail)
{
char *phead = findstr(str, head);
char *ptail = findstr(str, tail);
if(phead != NULL && ptail != NULL)
{
ptail += strlen(tail);
*ptail = '\0';
printf ("%s\n", phead);
}
}
int main()
{
char str[] = "fafgaasdheadhauboisoktailadad";
findframe(str, "head", "tail");
return 0;
}
