#!/usr/bin/perl

use strict;
use warnings;
use Net::FTP::File;

use constant HOST => 'ftp.perl.org';
use constant DIR  => '/pub/CPAN';
use constant FILE => 'README';

my $ftp = Net::FTP->new(HOST, Debug => 1) or die "Couldn't connect: $@\n";
$ftp->login('anonymous');
$ftp->cwd(DIR);
$ftp->put(FILE) unless $ftp->isfile(FILE);
warn "File exists.\n";
$ftp->quit;