cmdsrv

simple text protocol command server

npm install cmdsrv
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cmdsrv

NPM version

cmdsrv is a simple text protocol server that allows you to easily define the protocol and it's handlers.

The goal of cmdsrv is to be a very simplistic way to create your own text based protocol (like the memcached protocol).

Example Protocol

GET <KEY>
SET <KEY> <VALUE>
DEL <KEY>
STATS

Installation

Via Git

git clone git://github.com/brettlangdon/cmdsrv.git
cd ./cmdsrv
npm install

Via NPM

npm install cmdsrv

Usage

var cmdsrv = require("cmdsrv");

var data = {};

var server = new cmdsrv();

server.on("get", function(connection, key){
    // `connection` is just a normal `net.Socket` connection
    var result = data[key] || "";
    connection.write("RESULT " + result + "\r\n");
});

server.on("set", function(connection, key, value){
    data[key] = value;
    connection.write("SAVED\r\n");
});

server.start();

API

cmdsrv([options])

This is the constructor for cmdsrv and should be invoked as new cmdsrv().

options

  • port - which port to bind to when calling start (default: 3223)
  • delimiter - which character to split each command on (default: " ")
  • bound - which character is used as word boundaries (default: '"')
  • caseSensitive - whether or not the commands should be case sensitive, this means that "GET" and "get" will both be emitted as "get" (default: false)
  • tokenizer - a function(line, delimiter, bound) which returns a list of tokens for the line, if tokenizer is undefined then no tokenization will occur and only the line event will be emitted (default: see lib/tokenizer.js)

cmdsrv.on(command, handler)

Received commands are emitted to any handlers listening for that command.

command

command is the command you want to be able to handle with handler. For example, "get" would mean that handler gets called for each call to the "get" command.

If caseSensitive == true then "GET" !== "get"

handler

handler is a function which gets called every time the command is seen.

The definition for handler will be (connection, [arg1, arg2, ...]), where connection is the client connection (useful for sending responses back with connection.write(data)) and the args are the arguments sent with the command. For example if the client sent the command "get hello" then the function definition for handler might look like function(connection, key) where connection is the net.Socket of the user who sent the command and key is "hello".

cmdsrv.start(callback)

Start the server.

callback

An options callback that gets called when the server is listening.

Default Events

  • error - this is simply the client connection error event being bubbled up to the server. listener definition: function(error)
  • line - this is called with each raw line (not split on delimiter or command lowered, etc). listener definition: function(connection, line)
  • connection - this is called with each new connection. listener definition function(connection)

License

The MIT License (MIT)

Copyright (c) 2013 Brett Langdon <brett@blangdon.com> (http://www.brett.is)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
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