#!/usr/bin/perl
use threads;
use threads::shared;
use Term::ProgressBar;

${$task . '_src_filesize'};
share(${$task . '_src_filesize'});

${$task . '_dst_filesize'};
share(${$task . '_dst_filesize'});

# fork copy to a new thread, so it runs in the background
${'copy_' . $task . '_thread'} = threads->create(sub {
    print "Copying: $task/dist/$task.zip to /mnt/nfs/$task/$rel.zip\n"
+;
    system("cp $task/dist/$task.zip /mnt/nfs/$task/$rel.zip");

    while (${$task . '_src_filesize'} != ${$task . '_dst_filesize'} ) 
+{
        ${$task . '_dst_filesize'} = stat("/mnt/nfs/$task/$rel.zip")->
+size;
    }

    if (-e "/mnt/nfs/$task/$rel.zip") {
        print "Copied: $task/dist/$task.zip to /mnt/nfs/$task/$rel.zip
+\n";
        unlink("$task/dist/$task.zip");
    }
});

$progress = Term::ProgressBar->new({
    name    => 'Copy',
    count    => ${$task . '_src_filesize'},
    ETA    => 'linear',
});

$progress->minor(0);

while (${$task . '_src_filesize'} != ${$task . '_dst_filesize'}) {
    $progress->update(${$task . '_dst_filesize'})
}
[download]

I'm having some trouble using the progress bar for the first time. I'm running a copy in a thread and once everything else completes I want to monitor the progress. The example snippets I gave result in the bar completing @ 5%.