#!/usr/bin/perl

use strict;
use Tk;
use Tk::ROText;
use Tk::ProgressBar;

my ($complete_steps,$steps,$progress,$pid) = (14,0,0,undef);

my $mw = new MainWindow;
my $button = $mw->Button(-text => 'Run', -command => sub{&run})->pack();
my $pb = $mw->ProgressBar(-variable=>\$progress,-width => 20,-blocks=>100,-gap => 0)->pack(-fill => 'x', -expand => 1);
my $output = $mw->Scrolled('ROText', -scrollbars => 'osoe', '-wrap','none')->pack(-anchor => 'nw', -fill => 'both', -expand => 1);

MainLoop();

sub run {
	my $cmd = "...";
	my ($flag,$cmd_handle);
	$pid = open ($cmd_handle, "$cmd 2>&1 |") or $flag = $!;
	unless ($flag){
		$mw->fileevent($cmd_handle,'readable', [\&working,$cmd_handle]);
	} else{}	
}

sub working {
	my ($cmd_handle) = @_;
	my $redline;

	my $stat = sysread $cmd_handle, $redline, 4096;
	unless ($stat == 0) {
		$output->insert('end', "$redline");$output->yview('end');
		&update_remaining($redline);
	} else {
		$mw->fileevent($cmd_handle ,'readable','');
		$steps = 0;
		$progress = 0;
	}
}

sub update_remaining {
	my ($redline) = @_;
	my @list= ($redline =~ /Now/g);
	$steps += scalar(@list);
	my $temp = 100 * ($steps/$complete_steps);
	$progress = $temp;
}