# include <stdio.h>
int main()
{    
    int pid;
    pid=getpid();
    
    printf("Current Process ID is : %d\n",pid);

    printf("[ Forking Child Process ... ] \n");    
    pid=fork(); /* This will Create Child Process and
               Returns Child's PID */
if(pid < 0)
    {
        /* Process Creation Failed ... */

        exit(-1);
    }
    elseif(pid==0) 
    {
        /* Child Process */

        printf("Child Process is Sleeping ...");
        sleep(5);

        /* 
           Orphan Child's Parent ID is 1
                */

        printf("\nOrphan Child's Parent ID : %d",getppid());
    }
    else 
    {
        /* Parent Process */

        printf("Parent Process Completed ...");
    }    
    return 0;
}

/* Output

[divyen@localhost PP-TW1]$ ./Prog01-O &
[1] 2277
Current Process ID is : 2277
[ Forking Child Process ... ]
Parent Process Completed ...[divyen@localhost PP-TW1]$ ps -l
F S   UID   PID  PPID  C PRI  NI ADDR    SZ WCHAN  TTY          TIME CMD
0 S   500  2193  2192  0  75   0    -  1078 wait4  pts/2    00:00:00 bash
1 S   500  2278     1  0  75   0    -   336 schedu pts/2    00:00:00 Prog01-O
0 R   500  2279  2193  0  81   0    -   787 -      pts/2    00:00:00 ps
[1]+  Done                    ./Prog01-O
[divyen@localhost PP-TW1]$ Child Process is Sleeping ...
Orphan Child's Parent ID : 1

*/