C: SIGALRM - alarm to display message every second

Question

So I\'m trying to call an alarm to display a message \"still working..\" every second. I included signal.h.

Outside of my main I have my function: (I never declare/d

Answer 1

Do not call alarm() twice, just call it once in main() to initiate the callback, then once in display_message(). Try this code on Linux (Debian 7.8) :

#include  
#include  

void display_message(int s);   //Function for alarm set up

void display_message(int s)
{
     printf("copyit: Still working...\n" );
     alarm(1);    //for every second
     signal(SIGALRM, display_message);
}

int main()
{
    signal(SIGALRM, display_message);
    alarm(1);     // Initial timeout setting

     while (1) 
     {   
          pause();
     }   
}

The result will be the following one :

copyit: Still working...
copyit: Still working...
copyit: Still working...
copyit: Still working...
copyit: Still working...
copyit: Still working...
copyit: Still working...
copyit: Still working...
copyit: Still working...
copyit: Still working...
copyit: Still working...
copyit: Still working...