Good thought! I was hoping that was it, but alas, it even fails when using $qqq:

#!/usr/bin/perl

use English;
use strict;
use Data::Dumper;
use Tk;

my $qqq = '-l';
my $www = '-l';

# Setup remote ssh connection...
my $host='rhost';
use Net::SSH::Perl;
#use Net::SSH::W32Perl;                     # For windows
#my $ssh = Net::SSH::W32Perl->new($host)    # For windows
my $ssh = Net::SSH::Perl->new($host) ||
    die "Bad $host";
$ssh->login('rusr', 'rpass') || die "Bad login";

# Create new window...
my $top = MainWindow->new(-title=>'Options Test');
$top->minsize(470,225);
my $f = $top->Frame()->pack;
my $t = $top->Scrolled('Text')->pack;

# Add checkbuttion in frame...
$f->Checkbutton(-text=>$qqq,
    -offvalue=>'', -onvalue=>$qqq,
    -variable=>\$qqq, -command=>\&hostls,
)->pack(-side=>'left');
# Reset checkbutton variable (default is off)...
$qqq='';

sub hostls
{
    print STDERR Dumper(\$qqq);
    print STDERR "qqq=$qqq\n";
    $t->delete('1.0', 'end');
    my($stdout, $stderr, $exit) = $ssh->cmd("ls $qqq");    # Fails
    #my($stdout, $stderr, $exit) = $ssh->cmd("ls $www");    # Works
    if($exit) { warn "Bad Command return\n$stderr"; return() };
    $t->insert('end', $stdout);
}

MainLoop();
[download]

Thanks

-Craig