Linux中 信号signal

#include <stdio.h>
#include <signal.h>


void myhandler(int signal)
{

}

int mysleep(int timeout)
{
    struct sigaction act, oact;
    act.sa_handler = myhandler;//自定义处理函数
    sigemptyset(&act.sa_mask);
    act.sa_flags = 0;
    sigaction(SIGALRM, &act, &oact); //信号处理函数

    alarm(timeout);//设置闹钟
    pause();
    int ret = alarm(0);//清空闹钟
    sigaction(SIGALRM, &oact, NULL);// 恢复默认信号处理动作
    return ret;
}

int main()
{
    while(1)
    {
        mysleep(3);
        printf("use mysleep!\n");
    }
    signal(2, myhandler);
    return 0;
}