Mojo::UserAgent progress bar

mojo-progress-bar.pl

BEGIN { $ENV{MOJO_MAX_MESSAGE_SIZE} = 1024**3 }
use strict;
use Mojo::UserAgent;

my $ua = Mojo::UserAgent->new;
$ua->on(start => sub {
    my ($ua, $tx) = @_;
    my $progress = 0;

    $tx->res->on(progress => sub {
        my $msg = shift;
        return unless my $len = $msg->headers->content_length;

        my $size = $msg->content->progress;
        my $current = int($size / ($len / 100));
        # print each % increase, to avoid spam
        if ($progress < $current) {
            local $| = 1;
            $progress = $current;
            print "\rDownloading: ", $size == $len ? 100 : $progress, "%\n";
        }

    });
});

my $tx = $ua->get('http://mirror.yandex.ru/debian-cd/7.8.0/amd64/iso-cd/debian-7.8.0-amd64-CD-1.iso');

print $tx->error ? "\nDownloading failed: ".$tx->error->{message} : "\nDownloading finished!\n";