fork

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

int main()
{
    int i = 10;
    pid_t pid;
    printf("Father's pid:%d\n", getpid());

    pid = fork();
    if(pid < 0)
    {
        perror("fork failure!");
        return -1;
    }
    else if(pid == 0)
    {
        //while(1)
        {
            i++;
            printf("Child's i = %d\n", i);
            sleep(1);
        }
    }
    else
    {
        printf("Child's pis:%d\n", pid);
        //while(1)
        {
            printf("Father's i = %d\n", i);
            sleep(1);
        }
        sleep(1);
    }

    return 0;
}