use strict;
use warnings;

$| = (@ARGV > 0);
print "this is partial line....";
sleep (20);
print "the rest of the story\n";

##</code><code>##

use strict;
use warnings;

open FILE, '>', 'test' or die;
select FILE;  #this is important for $| the hard disk file!
$| = (@ARGV > 0);

print STDERR "partial line going to disk";
print FILE "this is partial line....";
sleep (20);
print FILE "the rest of the story\n";
print STDERR "line is complete\n";
print STDERR "starting another sleep\n";
sleep(20);
print STDERR "program ended\n";