sub open {
    @_ >= 2 && @_ <= 4 or croak 'usage: $fh->open(FILENAME [,MODE [,PERMS]])';
    my ($fh, $file) = @_;
    if (@_ > 2) {
	my ($mode, $perms) = @_[2, 3];
	if ($mode =~ /^\d+$/) {
	    defined $perms or $perms = 0666;
	    return sysopen($fh, $file, $mode, $perms);
	} elsif ($mode =~ /:/) {
	    return open($fh, $mode, $file) if @_ == 3;
	    croak 'usage: $fh->open(FILENAME, IOLAYERS)';
	} else {
            return open($fh, IO::Handle::_open_mode_string($mode), $file);
        }
    }
    open($fh, $file);
}