@Override
	protected AbstractPSystem executeLine(String line) {
		try {
			if (line.matches("(?i)^(authors?|about)\\s*$")) {
				return PSystemVersion.createShowAuthors();
			}
			if (line.matches("(?i)^version\\s*$")) {
				return PSystemVersion.createShowVersion();
			}
			if (line.matches("(?i)^testdot\\s*$")) {
				return PSystemVersion.createTestDot();
			}
			if (line.matches("(?i)^checkversion\\s*$")) {
				return PSystemVersion.createCheckVersions(null, null);
			}
			final Pattern p1 = Pattern.compile("(?i)^checkversion\\(proxy=([\\w.]+),port=(\\d+)\\)$");
			final Matcher m1 = p1.matcher(line);
			if (m1.matches()) {
				final String host = m1.group(1);
				final String port = m1.group(2);
				return PSystemVersion.createCheckVersions(host, port);
			}
			final Pattern p2 = Pattern.compile("(?i)^checkversion\\(proxy=([\\w.]+)\\)$");
			final Matcher m2 = p2.matcher(line);
			if (m2.matches()) {
				final String host = m2.group(1);
				final String port = "80";
				return PSystemVersion.createCheckVersions(host, port);
			}
		} catch (IOException e) {
			Log.error("Error " + e);

		}
		return null;
	}