sub parsevcard
{
    my ($fh, $line) = @_;
    my $currentvcard = {};
    # check that $line is really the beginning of a vcard, else die
    # loop reading lines from <$fh> and putting them in $currentvcard, call $currentvcard->{AGENT} = parsevcard($fh, $line) if a BEGIN:VCARD is encountered
    return $currentvcard; # check for end vcard?
}