fork_test.c

#include <sys/types.h>
#include <unistd.h>

int fork_1()
{
    int childpid;
    int i;

    if (fork() == 0) {
        //child process
        for (i = 1; i <= 20; i++) {
            printf("This is child process\n");
        }
    } else {
        //parent process
        for (i = 1; i <= 2; i++) {
            printf("This is parent process\n");
        }
    }

    printf("step2 after fork() !! pid=%d\n\n", getpid());

}

int main()
{
    fork_1();
    return 0;
}