#!/usr/bin/perl
use Tk;
use Tk::ExecuteCommand;

my $mw = MainWindow->new;
$ec = $mw->ExecuteCommand(
    -command    => '',
    -entryWidth => 50,
    -height     => 10,
    -label      => '',
    -text       => 'Execute',
)->pack;
$ec->configure( -command => 'dir' );
$ec->execute_command;
$ec->bell;
$ec->update;

MainLoop;
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> There are other things you could do too, like embed a real xterm into the frame.

I believe that's exactly what I would like to do. How can that be done?

If you're really worried about buffering the output of the commands, why would you put it in a Tk widget at all? That will take up more memory than just the string output.

Also: IIRC matlab has a "shell" interface, which means you don't start matlab itself for each command, instead you start it once, and then send commands to its STDIN and read its STDOUT for the output. That can get complicated (mainly because you can run into deadlocks) but it's certainly possible. See perlipc and IPC::Open3 and Tk::fileevent.

Update: If it's possible in your situation, you can simplify your program by using the Tk::Text (or Tk::ROText) widget for output only, and let the user enter the commands in a seperate text field below the output widget. That way you won't have to do all kinds of funky things with the keyboard events.

#!/usr/bin/perl -w
use strict;
use Tk;

my $mw = MainWindow->new();

my $canv = $mw->Canvas(-bg => 'lightsteelblue',
     -relief => 'sunken',
     -width => 500,
     -height => 400)->pack(-expand => 1, -fill => 'both');

my $xtermWidth = 400;
my $xtermHeight = 300;

## this Frame is needed for including the xterm in Tk::Zinc 
my $xtermContainer = $canv->Frame(-container => 1);
my $xtid = $xtermContainer->id();
print "$xtid\n";

# converting the id from HEX to decimal as xterm requires a decimal Id
+ 
my ($xtId) = sprintf hex $xtid;
print "$xtId\n";

my $label = $canv->createText( 250,10,
       -text => "Hide xterm",
       );


my $dcontitem = $canv->createWindow(250,175,
   -window => $xtermContainer,
   -width => $xtermWidth+4,
   -height => $xtermHeight+4,
   -state => 'normal');


$canv->bind($label, '<1>', \&hideShow);

sub hideShow {
    if ($canv->itemcget($label, -text) =~ /Hide/) {
          $canv->itemconfigure($label,
                    -fill => 'yellow',
                    -text => "Show xterm");
       $canv->itemconfigure($dcontitem, -state => 'hidden');
    } else {
         $canv->itemconfigure($label,
                    -fill => 'black',
                    -text => "Hide xterm");
       $canv->itemconfigure($dcontitem, -state => 'normal');
    }
    }

    my $width = $xtermWidth/10;
    my $height = $xtermHeight/20;

$mw->Button(-text => "Toplevel", -command => \&do_Toplevel)->pack(  );

system("xterm -fn 10x20 -geometry ${width}x${height} -into $xtId &");

MainLoop();


sub do_Toplevel {

   my $tl = $mw->Toplevel(-use=>$xtId );
    $tl->title("Toplevel");
    $tl->Button(-text => "Close",
                -command => sub { $tl->withdraw })->pack;
}
__END__
[download]

#!/usr/bin/perl -w
use strict;
use Tk;
use Tk::Zinc;
use Proc::ProcessTable;

my $title = time();
my $xtermparentpid;
my $pttydev;
my $id;
my $count = 0;

my $mw = MainWindow->new();

my $zinc = $mw->Zinc(-backcolor => 'gray',
     -relief => 'sunken',
     -width => 400,
     -height => 300)->pack(-expand => 1,
   -fill => 'both');

my $xtermWidth = 300;
my $xtermHeight = 200;

## this Frame is needed for including the xterm in Tk::Zinc 
my $xtermContainer = $zinc->Frame(-container => 1);
my $xtid = $xtermContainer->id();

# converting the id from HEX to decimal as xterm requires a decimal Id
+ 
my ($xtId) = sprintf hex $xtid;

my $label = $zinc->add('text', 1,
       -text => "Hide xterm",
       -position => [150, 30]);

my $dcontitem = $zinc->add('window', 1,
   -window => $xtermContainer,
   -position => [50, 75],
   -width => $xtermWidth+4,
   -height => $xtermHeight+4,
   -visible => 1);


$zinc->bind($label, '<1>', \&hideShow);

sub hideShow {
    if ($zinc->itemcget($label, -text) =~ /Hide/) {
$zinc->itemconfigure($label,
      -color => 'yellow',
      -text => "Show xterm");
 $zinc->itemconfigure($dcontitem, -visible => 0);
    } else {
$zinc->itemconfigure($label,
     -color => 'black',
     -text => "Hide xterm");
$zinc->itemconfigure($dcontitem, -visible => 1);
    }
    }

    my $width = $xtermWidth/10;
    my $height = $xtermHeight/20;

system("xterm  -T $title -fn 10x20 -geometry ${width}x${height} -into 
+$xtId &");

my $button = $mw->Button(-text => "Start", -command => \&do_slave_writ
+e)->pack();
my $exit = $mw->Button(-text => "Exit", -command => sub{Tk::exit})->pa
+ck();

MainLoop();


sub do_slave_write{

$button->configure(-text => 'Stop', -command => \&do_slave_stop);
$mw->update;

my $t = new Proc::ProcessTable;
      foreach my $p (@{$t->table}) {
        if($p->cmndline =~ /$title/){$xtermparentpid = $p->pid}
     }
        foreach my $p (@{$t->table}) {
      if($p->ppid == $xtermparentpid){$pttydev = $p->ttydev}
     }

open(FH,">$pttydev") or warn $!;

$id = Tk::After->new($mw,1000,'repeat',
       sub{print STDOUT $count,"\n"; print FH $count.'a',"\n";$count++
+});
}

sub do_slave_stop{
  $id->cancel;
  $button->configure(-text => 'Start', -command => \&do_slave_write);
  $mw->update;
#  $count=0; close FH; #to reset count  
}
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