Makes a process that is not killable with ^C (Unix Only)

nokill.c

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

void handler(int num){
  write(STDOUT_FILENO, "Kill Proceess Request Failed\n", 13);
}

int main() {
  signal(SIGINT, handler);
  for(;;){
    printf("Process ID: %d\n". getpid());
    sleep(1);
  }
}