#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
void handler()
{
printf("hello\n");
}
int main(void)
{
int i;
signal(SIGALRM,handler);
alarm(5);
for(i=1;i<7;i++)
{
printf("sleep %d seconds...\n",i);
sleep(1);
}
return 0;
}
https://www.bilibili.com/video/BV1k8411575T/?vd_source=d68ed178f151e80fea1e02efd205802c