#!/usr/bin/perl
use warnings;
use strict;

use Tk;

my $mw       = 'Tk::MainWindow'->new(-title => 'File path test');
my $f        = $mw->Frame->pack;
my $file_w   = $f->Entry(-textvariable => \ (my $file = '/'));
my $file_b   = $f->Button( -text    => 'Open File',
                           -command => sub { $file = $mw->getOpenFile },
)->pack;
$file_w->pack;
my $show_b   = $f->Button( -text => 'Show',
                           -command => sub {
                               open my $FH, '<', $file or die $!;
                               print while <$FH>;
                           })->pack;

MainLoop();