/***  Example of alarm function and SIGALRM signal.  ***/
#include<stdio.h>
#include<stdlib.h>
#include<signal.h>
#include<unistd.h>

void end(int sig){
  fprintf(stderr,"\n Sorry, time out!\n");
  kill(getpid(),SIGKILL);
  }

int main(){
  int a;
  signal(SIGALRM,end);
  alarm(5);
  printf(" Write an integer number within 5 seconds: ");
  scanf("%d",&a);
  printf(" %ds remained.\n I am processing the data...\n",alarm(0));
  sleep(6); // working with the number
  printf(" The number was: %d\n",a);
  return 0;
  }