atexit函数的使用【学习笔记】

 #include "apue.h"
 
 static void my_exit1(void);
 static void my_exit2(void);
 
 int main(void)
 {
     int ret = -;
 
     ret = atexit(my_exit2);
     if(ret != )
         err_sys("can't not register my_exit2\r\n");
 
     ret = atexit(my_exit1);
     if(ret != )
         err_sys("can't not register my_exit1\r\n");
 
     ret = atexit(my_exit1);
     if(ret != )
         err_sys("can't not register my_exit1\r\n");
 
     printf("main done\r\n");
 
     exit();
 
 }
 
 static void my_exit1(void)
 {
     printf("first exit handler\r\n");
 }
 static void my_exit2(void)
 {
     printf("second exit handler\r\n");
 }