Fork and wait system calls

fork_and_wait.c

include <stdio.h>
include <stdlib.h>
include <unistd.h>
include <sys/wait.h>

int main(int argc, char *argv[]) 
{
    printf("hello world (pid:%d)\n", (int) getpid());
    int rc = fork();
    // Fork failed, let's exit.
    if (rc < 0) {
        fprintf(stderr, "fork failed\n");
        exit(1);
    } else if (rc == 0) { 
        // child process created successfully
        printf("hello, I am child (pid:%d)\n", (int) getpid());
    } else {
        // Parent process continue here and block/wait for the child to finish.
        int rc_wait = wait(NULL);
        printf("hello, I am parent of %d (rc_wait:%d) (pid:%d)\n",
                rc, rc_wait, (int) getpid());
    }
    return 0;
}