Just for curiousity, i tried the following:

#!/usr/bin/perl -w

while(<>) { print };
seek(STDIN, 0, 0) or die; 
print "-----PASS 2-----\n"; 
while(<>) {print}
[download]

When doing

 
    >cat t.pl  | perl t.pl
[download]

Because that's a seekable file! Try it with cat t.pl | program instead.

-- Randal L. Schwartz, Perl hacker