8. Ignoring Signals

A process can ignore a signal by setting up the return value to SIG_IGN. Here the process would always be ignored by the handler. For e.g. :-

#include <stdio.h>
#include <unistd.h>
#include <signal.h>
void ouch(int sig)
{
    printf("OUCH! - I got signal %d\n", sig);
    (void) signal(SIGINT, SIG_IGN);
}
int main()
{
    (void) signal(SIGINT, ouch);

    while(1)
    {
        printf("Hello World!\n");
        sleep(1);
    }
}
Here the SIGINT signal would be ignored, whenever we press it the system would ignore it, and it would result an infinite loop of Hello World.