How do I make a progress bar using Term::ProgressBar with LWP::UserAgent's post method?

#!/usr/bin/perl

use LWP::UserAgent;
use HTTP::Request::Common;
use HTML::TreeBuilder;
use Cwd 'realpath';

use warnings;
use strict;

my $ua = LWP::UserAgent->new();

my $response = $ua->request(
                POST 'http://mydomain.com/upload.php',
开发者_开发问答                'Content-Type' => 'multipart/form-data',
                'Content' => [ 'fileup' => [realpath(shift)] ],
              );

my $tree = HTML::TreeBuilder->new_from_content($response->decoded_content);

my $image = $tree->look_down('_tag','a',sub { $_[0]->{href} =~ /http:\/\/images.mydomain.com\/images\/[^\?]/ if $_[0]->{href}})->{href};
print "\n".$image."\n\n";

How do I create a progress bar for this script showing the upload? :content_cb let's you create progress bars for the response after the image is uploaded, so how do I do it for the upload itself?

This doesn't answer your initial question, but maybe you can use the builtin progress bar instead:

$ua->show_progress
$ua->show_progress( $boolean )
    Get/set a value indicating whether a progress bar should be displayed on on the
    terminal as requests are processed. The default is FALSE.

(from LWP::UserAgent POD)