% perldoc -q rand
Found in
     /home/columbia3/gclib/pkg/perl/lib/5.8.0/pod/perlfaq4.pod
     Why aren't my random numbers random?

             If you're using a version of Perl before 5.004, you
             must call "srand" once at the start of your program
             to seed the random number generator.  5.004 and
             later automatically call "srand" at the beginning.
             Don't call "srand" more than once--you make your
             numbers less random, rather than more.
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Excellent point!! Thanks

#!/usr/bin/perl
use Tk;
my $i=1;
my $mw=tkinit;

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

$mw->Button(-text=>'Get rand',
            -command =>
             sub{ for (1..100){
              my $rand = rand(10000000);
              $text->insert('end',"$rand ");
              }
           $text->insert('end',"\n\n\n");
     }
    )->pack;

MainLoop;
__END__
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I just tried the following on ActivePerl on Win32.

use Tk;

my $mw = Tk::MainWindow->new;
my $txt = $mw->Label(-text=>"Value:");
$txt->pack;
$mw->Button(-text=>"Ok", -command=>sub {$txt->configure(-text=>"Value:
+ " . rand)})->pack;
srand (time | $$);
$mw->MainLoop;
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Update: Note that in my example I only call srand once. I tried it again with the srand call inside the callback function and I got a similar result to yours.

As I recall, there hasn't been a need to seed rand since Perl 5.004.. In newer versions, rand is automatically seeded if called.

PS - And if I was seeding rand, I wouldn't seed it that way... See perldoc -f srand, perldoc -f rand, perldoc -q rand.

Update: Oh. Well. Maybe if I answered questions in a timely manner, instead of floating on a node for awhile and not refreshing to see if any answers have been added, then I wouldn't have duplicated Roy's post :).

sub button_press {
    srand(time|$$);
    my $rand = rand();
    ... display $rand ...
}
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