sub shellwords {
    package shellwords;
    local($_) = join('', @_) if @_;
    my $tainted = substr $_,0,0 if defined; # give me an tainted empty string
    local(@words,$snippet,$field);

    s/^\s+//;
    while ($_ ne '') {
	$field = '';
	for (;;) {
	    if (s/^"(([^"\\]|\\.)*)"//) {
		($snippet = $1) =~ s#\\(.)#$1#g;
	    }
	    elsif (/^"/) {
		die "Unmatched double quote: $_\n";
	    }
	    elsif (s/^'(([^'\\]|\\.)*)'//) {
		($snippet = $1) =~ s#\\(.)#$1#g;
	    }
	    elsif (/^'/) {
		die "Unmatched single quote: $_\n";
	    }
	    elsif (s/^\\(.)//) {
		$snippet = $1;
	    }
	    elsif (s/^([^\s\\'"]+)//) {
		$snippet = $1;
	    }
	    else {
		s/^\s+//;
		last;
	    }
	    $field .= $snippet;
	}
	push(@words, $field);
    }

    # this loop will retaint the variables
    foreach ( @words ) {
    	$_ .= $tainted if defined;
    }
    @words;
}