chat2

A simple telnet app to chat with a server. It uses send and expect to chat and wait for an expected response. There is also an exec method to send and expect in sequence.

This module allows you to chat programatically to any server such as a POP3 server or an SMTP server that uses a known protocol that can be sent to and expected. It uses native Promises and is pipeline safe: you can send and expect from multiple async calls and the data will arrive back in the right order.

Install

npm install chat2

Example

static Chat2 = require('chat2');

static chat = new Chat2('localhost', 110, 5000);
chat.connect()
.then(() => {
  chat.expect(/^\+OK/);
})
.then(() => {
  chat.send('USER cliff');
  chat.exec('PASS password', /^+OK/);
})
.then(response => {
  console.log(response);
  chat.send('QUIT');
  chat.close()
})

Constructor

const chat2 = new Chat2(host, port, timeout);

host

hostname or IP address

port

a numeric port, defaulting to 23 if not provided

####timeout

a timeout in milliseconds, defaulting to no timeout

Methods

connect

chat2.connect();

This sets up the connection to the server, sets encoding to utf-8 and sets a keepalive. It mus be called before any other methods.

expect

chat2.expect(<pattern>)
.then(line => {
  console.log("Received: " + line);
});

Called with a regular expression, it returns a promise. The promise resolves when the regular expression is matched, returning the full line that matched.

send

chat2.send(<message>)
.then(() => {
});

Sends a message to the server, returning a promise. The promise resolves with the message sent.

exec

chat2.exec(<message>, <pattern>)
.then(line => {
  console.log("Received: " + line);
});

This calls send followed by expect. It returns a promise which is resolved to the first line that matches the pattern.

Both expect and exec will reject the promise if the timeout is reached. The caught error will be of type ETIMEDOUT.

close

chat2.close()

This will close the connection cleanly and leave the chat2 instance ready to be reconnected, if desired.

History

This program is called chat2 as it was inspired by Randal L. Schwartz' Perl 4 program chat2.pl from 1991.

Similar programs

The teletype module is similar but will lose data if it comes in too fast.

Issues

Please let me know of any issues at the Github Issues page.