public static void main(String[] args) throws Exception {
        TikaCLI cli = new TikaCLI();

        if (cli.testForHelp(args)) {
            cli.usage();
            return;
        } else if (cli.testForAsync(args)) {
            async(args);
            return;
        }

        if (args.length > 0) {
            for (String arg : args) {
                cli.process(arg);
            }
            if (cli.pipeMode) {
                cli.process("-");
            }
        } else {
            // Started with no arguments. Wait for up to 0.1s to see if
            // we have something waiting in standard input and use the
            // pipe mode if we have. If no input is seen, start the GUI.
            if (System.in.available() == 0) {
                Thread.sleep(100);
            }
            if (System.in.available() > 0) {
                cli.process("-");
            } else {
                cli.process("--gui");
            }
        }
    }
Password for opening encrypted documents, or <code>null</code>.
tika-app/src/main/java/org/apache/tika/cli/TikaCLI.java