getppid() and getpid() in Linux

// C++ Code to demonstrate getppid()
#include <iostream>
#include <unistd.h>
using namespace std;

// Driver Code
int main()
{
    int pid;
    pid = fork();
    if (pid == 0)
    {
        cout << "\nParent Process id : " 
             << getpid() << endl;
        cout << "\nChild Process with parent id : " 
             << getppid() << endl;
    }
    return 0;
}

// C++ Code to demonstrate getpid()
#include <iostream>
#include <unistd.h>
using namespace std;

// Driver Code
int main()
{
    int pid = fork();
    if (pid == 0)
        cout << "\nCurrent process id of Process : " 
             << getpid() << endl;
    return 0;
}