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Running a "full-featured" REPL using a net.Server and net.Socket
var net = require('net')
var sock = net.connect(1337)
sock.on('connect', function () {
sock.on('close', function done () {
sock.removeListener('close', done)
process.stdin.on('end', function () {
process.stdin.on('data', function (b) {
if (b.length === 1 && b[0] === 4) {
var repl = require('repl')
var net = require('net')
net.createServer(function (socket) {
var r = repl.start({
prompt: 'socket '+socket.remoteAddress+':'+socket.remotePort+'> '
, input: socket
, output: socket
, terminal: true
, useGlobal: false
r.on('exit', function () {
r.context.socket = socket
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benbuckman commented Jun 27, 2012

Hi Nate,
I'm trying to set up a repl with stdout piped to it, this seems like a good demo. But when I run this with node 0.6.19, I get this error:

TypeError: Object #<ReadStream> has no method 'setRawMode'
    at Socket.<anonymous> (nodejs/repl-demo/repl-client.js:10:17)
    at Socket.emit (events.js:64:17)
    at Object.afterConnect [as oncomplete] (net.js:652:10)

What am I missing?

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TooTallNate commented Jun 27, 2012

@newleafdigital You need node v0.8.0 for this example.

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benbuckman commented Jun 27, 2012


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benbuckman commented Jun 27, 2012

Is there any way in 0.6 to pipe stdout / console.log to a repl, so while I'm running commands, I can see the logs? It seems like it should be straightforward, but I can't get it to work.

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AlexeyKupershtokh commented Jun 29, 2012

    r.context.inspect = function(value) {
        r.outputStream.write('\n' + r.writer(value) + '\n');

This method is useful as callback to inspect values when console.log() is unavailable.
Example of usage:

socket> setTimeout(function() {inspect(user);}, 1000);null;
null // immediate reaction
{ coins: 10 } // after the timeout

Though please be careful: this code crashes the server if repl client disconnects before the timeout.

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qzaidi commented Apr 21, 2013

Looks like this stopped working with 0.10.0, running the client results in the following error.

throw new Error('Cannot switch to old mode now.');

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sandover commented Jul 23, 2013

I'm curious, too -- I'd like a remote REPL participant to be able to see the results of whatever they do, in their own REPL, instead of having that output "leak" back into the terminal where the program is running.

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jakwings commented Dec 3, 2013


var socket = require('');

i am not getting remote addeess and it gives undefined


req.headers['x-forwarded-for'] it gives local ip address ...

i want remote ip address

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KrishnaAnanthi commented Apr 25, 2018

how to start the client and server in this application?

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KrishnaAnanthi commented Apr 25, 2018

i tried node repl-server.js it is giving me an error
throw err;

Error: Cannot find module 'C:\D Drive\Learning\repl-server.js'
at Function.Module._resolveFilename (module.js:536:15)
at Function.Module._load (module.js:466:25)
at Function.Module.runMain (module.js:676:10)
at startup (bootstrap_node.js:187:16)
at bootstrap_node.js:608:3

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