proper use of $r->read?

Hi,

What's the proper way to read in the posted content from a request?

Using this Google code search:

http://www.google.com/codesearch?q=lang%3Aperl+%5C%24r-%3Eread.*length&hl=en

I see instances of:

  $r->read($line, $r->headers_in->get('Content-length'));

and also loops like:

    while ( $r->read( $buffer, $content_length ) ) {
        $content .= $buffer;
    }

What's the best/proper way to slurp in all of the POST content?

Thanks,
ER