#!/usr/bin/perl -w
use Tk;
use Tk::Menubar;
use Cwd;
require Tk::Dialog;
require Tk::ROText;
use strict;

#-------------------------------------------------------------------
# Main Window Setup and configuration
#-------------------------------------------------------------------

my $MW = MainWindow->new();
$MW->title("TESTGUI ");

#-------------------------------------------------------------------
# Menubar
#-------------------------------------------------------------------

my $menubar = $MW->Menubar;

#-------------------------------------------------------------------
# Menubuttons
#-------------------------------------------------------------------

my $f   = $menubar->Menubutton( -text => 'File', -underline => 0 );
my $run = $menubar->Menubutton( -text => 'Run',  -underline => 0 );

#-------------------------------------------------------------------
# Menu sub-buttons
#-------------------------------------------------------------------

$f->command( -label => 'Close', -command => sub { exit }, -underline => 0 );
$run->command( -label => 'RUN PING COMMAND', -command => [ \&run_pc ] );

#-------------------------------------------------------------------
# Frame 1  - INPUT VARIABLES FRAME (Main body frame)
#-------------------------------------------------------------------
my $N    = 1;
my $frm1 = $MW->Frame;

my $tl1 = $frm1->Label(
    -text => "NOT IMPORTANT, JUST USED SPACE FOR
SETTING VARIABLES",
    -relief     => 'raised',
    -background => "gray"
  )->grid(
    -row        => 0,
    -column     => 0,
    -sticky     => 'nsew',
    -columnspan => 2
  );

$frm1->pack;

MainLoop;

#-------------------------------------------------------------------
# Run PC subroutine
#-------------------------------------------------------------------

sub run_pc {
    my $pcwin = new MainWindow( -title => "PC OUTPUT LOG WINDOW" );
    `ping -c 20 localhost > pc_output.log &`;
    my $pidpc = open( RUNCOMMANDD, "tail -f pc_output.log |" )
      || die $!;
    my $outputtext = $pcwin->Scrolled(
        "Text",
        -scrollbars => "e",
        -width      => 80,
        -height     => 45,
        -wrap       => "word"
    )->pack();
    my $quitbutn = $pcwin->Button(
        -text    => "Close",
        -command => sub {
            close(RUNCOMMANDD);
            kill 'TERM', $pidpc;
            `echo "bye" >>
pc_output.log`;
            $pcwin->fileevent( \*RUNCOMMANDD, 'readable' => '' );
            $pcwin->destroy;
        }
    )->pack();
    $pcwin->fileevent( \*RUNCOMMANDD, 'readable',
        [ \&fill_text_widget, $outputtext ] );
}

sub fill_text_widget {

    my ($widgett) = @_;
    my ( $stat, $data );
    $stat = sysread( RUNCOMMANDD, $data, 4096 );
    die "sysread error:  $!" unless defined $stat;
    $widgett->insert( 'end', $data );
    $widgett->yview('end');

}