/*

 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 *   - Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 *

 *   - Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 *

 *   - Neither the name of Oracle nor the names of its

 *     contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

// Usage: jjs shell.js

/* This is a simple shell tool in JavaScript.

 *

 * Runs any operating system command using Java "exec". When "eval" command is

 * used, evaluates argument(s) as JavaScript code.

 */

(function() {

    // Java classes used

    var Arrays = Java.type("java.util.Arrays");

    var BufferedReader = Java.type("java.io.BufferedReader");

    var InputStreamReader = Java.type("java.io.InputStreamReader");

    var ProcessBuilder = Java.type("java.lang.ProcessBuilder");

    var System = Java.type("java.lang.System");

    // print prompt

    function prompt() {

        System.out.print("> ");

    }

    var reader = new BufferedReader(new InputStreamReader(System.in));

    prompt();

    // read and evaluate each line from stdin

    reader.lines().forEach(function(line) {

        if (! line.isEmpty()) {

            var args = line.split(' ');

            try {

                // special 'eval' command to evaluate JS code

                if (args[0] == 'eval') {

                    var code = line.substring('eval'.length);

                    var res = eval(code);

                    if (res != undefined) {

                        print(res);

                    }

                } else {

                    // build child process and start it!

                    new ProcessBuilder(Arrays.asList(args))

                        .inheritIO()

                        .start()

                        .waitFor();

                }

            } catch (e) {

                // print exception, if any

                print(e);

            }

        }

        prompt();

    })

})()