/*
    forktest.c
    
    Started by Jeff Ondich on 3/26/96
    Last modified by Jeff 2/16/22
    Modified by Tanya Amert for Fall 2024
    
    This program gives a simple example of fork, and how
    a process can create a child process.

    To compile this program:

        gcc -Wall -Werror -Og -o forktest forktest.c

    To run this program:

        ./forktest
*/

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

const long LIMIT = 1e10; // 10,000,000,000 (1 with 10 zeros)
const long FREQUENCY = 5e8; // 500,000,000 (5 with 8 zeros)

// A simple demonstration of fork()
int main()
{
    if (fork() == 0)
    {
        /* Child */
        pid_t process_id = getpid();
        for (long k=0; k < LIMIT; k++)
        {
            if (k % FREQUENCY == 0)
            {
                printf("CHILD [%d]: %ld\n", process_id, k);
            }
        }
    }
    else
    {
        /* Parent */
        pid_t process_id = getpid();
        for (long k=0; k < LIMIT; k++)
        {
            if (k % FREQUENCY == 0)
            {
                printf("PARENT [%d]: %ld\n", process_id, k);
            }
        }
    }

    return 0;
}