Multiple STDIN sources

[perlfan]

I have a script that I want to direct an input stream to using either "|":

% cat myfile.txt | myprogram.pl

or "<":

% myprogram.pl < myfile.txt

The problem I have is that in the code I also ask for user input, and assign the answer to the question using <STDIN>. However the STDIN stream conflict, and I can not figure out how to "reset" STDIN. Here is my code that shows the problem:

#!/usr/bin/perl -w

use strict;

my $stream;

while (<>) {
  $stream .= $_;
}

print "Do you want to process the stream?";
my $ans = <STDIN>;

#...
exit;

Basically, perl blows right past the "my $ans = <STDIN>;" line. I have searched high and low - both here and on the web, and can not find the solution - do I need to reset STDIN? Doing a "close(STDIN)" causes errors, so I am not sure what to do. Thanks! Brett