Family_Of_processes_AsTree.cpp

// CPP code to create three child
// process of a parent
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

// Driver code
int main()
{
	int pid, pid1, pid2;

	// variable pid will store the
	// value returned from fork() system call
	pid = fork();

	// If fork() returns zero then it
	// means it is child process.
	if (pid == 0)
	{

		// First child needs to be printed
		// later hence this process is made
		// to sleep for 3 seconds.
		sleep(3);

		// This is first child process
		// getpid() gives the process
		// id and getppid() gives the
		// parent id of that process.
		printf("child[1] --> pid = %d and ppid = %d\n",
			   getpid(), getppid());
	}

	else
	{
		pid1 = fork();
		if (pid1 == 0)
		{
			sleep(2);
			printf("child[2] --> pid = %d and ppid = %d\n",
				   getpid(), getppid());
		}
		else
		{
			pid2 = fork();
			if (pid2 == 0)
			{
				// This is third child which is
				// needed to be printed first.
				printf("child[3] --> pid = %d and ppid = %d\n",
					   getpid(), getppid());
			}

			// If value returned from fork()
			// in not zero and >0 that means
			// this is parent process.
			else
			{
				// This is asked to be printed at last
				// hence made to sleep for 3 seconds.
				sleep(3);
				printf("parent --> pid = %d\n", getpid());
			}
		}
	}

	return 0;
}