# application/x-www-form-urlencoded
sub qparse{
    my $rawdata = shift; # querystring
    my %param = ();
    my @pie = split /[;&]/, $rawdata;
    foreach my $p(@pie){
        my ($pname, $val) = split(/=/, $p, 2);
        next unless $pname;
        next unless defined $val;
        $val =~ s/\+/ /g;
        $val =~ s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg;
        push @{$param{$pname}}, $val; # key => [val,val..]
    }
    return \%param;
}