#!/usr/bin/perl
use warnings;
use strict;
use threads;
use threads::shared;
use Tk;

my %shash;
#share(%shash); #will work only for first level keys
my %hash;

 share ($shash{'go'});
 share ($shash{'fileno'});
 share ($shash{'pid'});
 share ($shash{'die'});
 
 $shash{'go'} = 0;
 $shash{'fileno'} = -1;
 $shash{'pid'} = -1;
 $shash{'die'} = 0;

 $hash{'thread'} = threads->new(\&work);


my $mw = MainWindow->new(-background => 'gray50');

my $text = $mw->Scrolled('Text')->pack();

my $repeater;
my $buf;
my $startb = $mw->Button( -text => 'Start',
                -command=>sub{
                     $shash{'go'} = 1;
		     $mw->after(1000);
		     my $fileno = $shash{'fileno'};
                     print "fileno_m $fileno\n";
		
		  open (my $fh, "<&=$fileno") or warn "$!\n";

                   while(<$fh>){
		   
	      $text->insert('end',$_);	
              $text->see('end');	              
              $mw->update;
		   }


#                     $repeater = $mw->repeat(10,
#		        sub {
#		              my $bytes = sysread( $fh, $buf, 8192);
#			      $text->insert('end',$buf);	
#	                      $text->see('end'); 		
		#	      if( $shash{'go'} == 0 ){ $repeater->cancel }
		
		
#			   }
#			 );     		
		
             }
                 )->pack();

my $stopb = $mw->Button( -text => 'Stop',
                -command=>sub{
		
		         exit;
		      },
                 )->pack();


MainLoop;

##################################################################
sub work{
    $|++; 
    while(1){
       if($shash{'die'} == 1){ goto END }; 
      
       if ( $shash{'go'} == 1 ){

        my $pid = open(FH, "top -b |" ) or warn "$!\n";
        my $fileno = fileno(FH);
        print "fileno_t->$fileno\n";
        $shash{'fileno'} = $fileno;
       
    $shash{'go'} = 0; #turn off self before returning      
       }else
         { sleep 1 }
    }
END:
}
###################################