Process management using FORK() System Call

Ex. No.: 4(b)

Process management using FORK() System Call

AIM:

               Write a program in C to create the process hierarchy P1, P2, P3 using fork system call  

fork :  This system call produces new process. The new process contains the address space of the original space.

wait : The parent can issue a wait system call to wait until the parent process completes.

exit : The process completes execution by executing the exit system call.

Program:

#include<stdio.h>

#include<sys/types.h>

#include<unistd.h>

void main()

{

   int pid1,pid2;

   //Fork create another process

   pid1=fork();

   if(pid1 != -1)

{

   if(pid1 != 0)

   {

        printf(“p1:%d\t%d”,getpid(), getppid());

        }

   {

      pid2=fork();

      if(pid2 != 0)

    {

            printf(“p2:%d\t%d”,getpid(), getppid());

          }

        else 

          printf("p3:%d\t%d”, getpid(), getppid());

            }

}

}

Output

[cs281016@linux]$cc fork.c

[cs281016@linux]$ ./a.out

   P3: 21019           21018

   P2: 21018           21017

   P1: 21017           20068

RESULT :

            Thus the program using the system call fork was written in C and executed successfully.