#!/usr/bin/perl -w
use strict;
$|=1;  #test was run with and without this statement
       #this turns buffering off

print "this is a test\n";
print "this is a test2\n";
print STDERR "this is an error after line2\n";
print "this is a test3\n";
print "this is a test4\n";

__END__
Prints: without $|=1........
this is an error after line2
this is a test
this is a test2
this is a test3
this is a test4

Prints: Now with $|=1 ......
this is a test
this is a test2
this is an error after line2
this is a test3
this is a test4