linux中sigaction函数详解

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

int main()
{
    struct sigaction newact,oldact;

    /* 设置信号忽略 */
    newact.sa_handler = SIG_IGN; //这个地方也可以是函数
    sigemptyset(&newact.sa_mask);
    newact.sa_flags = 0;
    int count = 0;
    pid_t pid = 0;

    sigaction(SIGINT,&newact,&oldact);//原来的备份到oldact里面

    pid = fork();
    if(pid == 0)
    {
        while(1)
        {
            printf("I'm child gaga.......\n");
            sleep(1);
        }
        return 0;
    }

    while(1)
    {
        if(count++ > 3)
        {
            sigaction(SIGINT,&oldact,NULL);  //备份回来
            printf("pid = %d\n",pid);
            kill(pid,SIGKILL); //父进程发信号，来杀死子进程
        }

        printf("I am father .......... hahaha\n");
        sleep(1);
    }

    return 0;
}

结果：