#include <iostream>
#include <unistd.h>
#include <stdio.h>

using namespace std;


int main(int argc, char * argv[]) {

    if (argc != 3) {
       cout << argv[0] << " oldfile newfile" << endl;
       return 1;
    }

    if (access(argv[1],F_OK) != 0) {
       cout << "No access to source " << argv[1] << endl;
       return 1;
    }

    if (access(argv[2],F_OK) == 0) {
       cout << "Warning: destination file " << argv[2] << " exists." << endl;
    }

    if (link(argv[1],argv[2]) != 0) {
       perror("Link failed ");
       cout << "Could not link " << argv[1] << " and " << argv[2] << endl;

    }

    return 0;
}