PREPL

NOTE This repository is not maintained, and I recently found a much more comprehensive solution: dthree/vorpal.

A simple, event-based, programmatic read-eval-print loop

var repl = require('prepl')();

repl.start();

Use nc to connect:

$ nc -u prepl.sock
> help
    COMMAND     DESCRIPTION
    help        Display this help message
    exit        Disconnect from REPL
> exit
$ 

Configuration

Default configuration:

{
    "name": "prepl",
    "socket": "prepl.sock"
}

Options

• name: name of the application using prepl. Default: prepl.
• socket: path to the socket to be used. Default: prepl.sock. See net.Server.listen(path, [callback])
• address: IP address to which the net server will bind. Default undefined. See net.Server.listen(port, [host], [backlog], [callback])
• port: the TCP port to which the net server will bind. Default undefined. See net.Server.listen(port, [host], [backlog], [callback])

API

Prepl

Exposed by require('prepl').

Prepl()

Creates a new Prepl. Works with and without new:

var prepl = require('prepl')();
  // or
var Prepl = require('prepl');
var repl = new Prepl();

Prepl(options:Object)

Optionally, the first argument of the Server constructor may be an options object to be passed to Prepl.configure.

Prepl.configure(options:Object)

• options Object A hash of options to override defaults

Configure the REPL:

repl.configure({
    address: '0.0.0.0',
    port: 1338,
    socket: undefined
});

Prepl.register(commands:Array)

• commands Array An array of commands to be registered

Registers the list of commands with the REPL. Command have a name identifier, a message to describe the command in the help menu, and a function to carry out the given command. This function is passed the socket object of the client connection to allow output to the client terminal. names may not exceed 15 characters.

var server = new MyServerApp({foo:'bar'};

repl.register([{
        name: "start",
        help: "Start the application",
        action: function () {
            console.log('cluster started');
        },
    },
    {
        name: "restart",
        help: "Restart the application",
        action: function () {
            console.log('cluster restarted');
        }
    }, 
    {
        name: 'update',
        help: 'Update the server\'s cached memory',
        action: function (socket) {
            server.update(function () {
            socket.write('cache updated');
        }
    }
})
]);

The command(s) will be now available and listed in the help menu.

> help
    COMMAND     DESCRIPTION
    help        Display this help message
    exit        Disconnect from REPL
    start       Start the application
    restart     Restart the application
>

Prepl.unregister(name:String)

• name String command to be unregistered

Unregister the given action:

repl.unregister('start');

The command will no longer be available or listen in the help menu:

> help
    COMMAND     DESCRIPTION
    help        Display this help message
    exit        Disconnect from REPL
    restart     Restart the application
>

Prepl.start(done:Function)

• done Function Optional callback to be called when REPL has started

Start the REPL:

repl.start(function () {
    console.log('the REPL server is now ready!');
})

Prepl.stop(done:Function)

• done Function Optional callback to be called when REPL has stopped

Stop the REPL:

repl.stop(function () {
    console.log('the REPL server has now stopped!');
})

Events

Event: 'starting'

Emitted before the REPL server starts:

repl.on('starting', function onReplStarting () {
    console.log('starting REPL server...');
});

Event: 'stopping'

Emitted before the REPL server stops:

repl.on('stopping', function onReplStopping () {
    console.log('stopping REPL server...');
});

Event: 'stopped'

Emitted once the REPL server has stopped:

repl.on('stopped', function onReplStopped () {
    console.log('REPL server stopped!');
});

Event: 'ready'

Emitted once the REPL server is ready:

repl.on('ready', function onReplReady () {
    console.log('the REPL server is ready!');
});