#!/usr/bin/perl -w
use strict;
use warnings;
open my $FH, "/tmp/test.txt" || die "Failed to open /tmp/test.txt: $!\n";

## NOT WORKING !!
while (my $Line = GetLine($FH)) {
        print "$Line";
}

## NOT WORKING !!
sub GetLine {
       my $line = <$_[0]> ;
       return $line;
}

##</code><code>##

sub GetLine {
        my $FH = shift;
        my $line = <$FH> ;
        return $line;
}