I have created following code to display hello! on command line screen

use strict;
use warnings;
use diagnostics;

open (DOG, ">not.txt") or die ("Cannot open not.txt");
print DOG "hello!";
open (DOG, "<not.txt") or die ("Cannot open not.txt");
while(<DOG>){
print;}
close (DOG);
[download]

And with previous code

use strict;
use warnings;
use diagnostics;

open (DOG, ">not.txt") or die ("Cannot open not.txt");
print DOG "hello!";
close (DOG);
[download]

I was thinking that the code only creates file and doesnot display contents of file on the command line screen.