use LWP::UserAgent;
use HTTP::Request::Common qw(POST);
$ua = new LWP::UserAgent;

$req =  POST ( 'http://www.page.com/app?cmd=upload',

        Content_Type => 'form-data',

        Content      => [ name  => 'value',

                         name   => 'value',

                         file   => ["/path/to/file.txt"],

                         ]
                 );

$response = $ua->request($req);