ttys

Guaranteed read and write streams to the terminal

This micro module provides tty.ReadStream and tty.WriteStream instances to the user's terminal, even when the regular stdin or stdout streams are already being piped to other commands.

Installation

Install with npm:

$ npm install ttys

The setup

Suppose you want to provide a curl | node command to your users.

The script could be something as simple as printing "Hello World" and exiting.

// script.js
console.log('Hello World')

Place that on your websever and have your users invoke the command:

$ curl aweso.me/script.js | node
Hello World

Awesome!!!

The problem

Now suppose that you wanted to alter script.js to prompt the user for their name, so that you can personalize it a little bit.

The problem is that process.stdin is used up because it gets piped from the curl command, and ends before node runs the script. If you try to call process.stdin.resume() and listen for "data" and "end" events, you will see that the "end" event will be fired immediately.

The solution

Using ttys, you can get guaranteed access to a stdin readable stream and stdout writable stream. It's easy!

var ttys = require('ttys')
var readline = require('readline')
 
var i = readline.createInterface(ttys.stdin, ttys.stdout)
i.question('What is your name? ', function (name) {
  console.log('Hello %s', name)
 
  i.close()
  ttys.stdin.pause()
})

Now when your users run the script, then they will be prompted as you would expect:

$ curl aweso.me/script.js | node
What is your name? Nathan
Hello Nathan

That's it!

License

(The MIT License)

Copyright (c) 2012 Nathan Rajlich <nathan@tootallnate.net>

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.