因为代码中使用了malloc函数和字符串函数。编译时出现错误
warning: incompatible implicit declaration of built-in function ‘malloc’
warning: incompatible implicit declaration of built-in function ‘bzero’
warning: incompatible implicit declaration of built-in function ‘strncpy ’
warning: incompatible implicit declaration of built-in function ‘strlen’
解决的方法：
增加头文件就可以
#include<stdlib.h>
#include<string.h>