emitLines.js

/**
 * By TooTallNate, originally posted at https://gist.github.com/1785026
 * A quick little thingy that takes a Stream instance and makes
 * it emit 'line' events when a newline is encountered.
 * Modified by Max Weller to accept custom line feed characters (e.g. \r\n)
 *
 *   Usage:
 *   ‾‾‾‾‾
 *  var emitLines = require('./emitLines');
 *  emitLines(process.stdin, "\n")
 *  process.stdin.resume()
 *  process.stdin.setEncoding('utf8')
 *  process.stdin.on('line', function (line) {
 *    console.log(line event:', line)
 *  })
 *
 */

function emitLines (stream, lineFeedChar) {
  var backlog = ''
  stream.on('data', function (data) {
    console.log("data in "+data.length+" bytes");
    backlog += data
    var n = backlog.indexOf(lineFeedChar)
    // got a \n? emit one or more 'line' events
    while (~n) {
      stream.emit('line', backlog.substring(0, n))
      backlog = backlog.substring(n + lineFeedChar.length)
      n = backlog.indexOf(lineFeedChar)
    }
  })
  stream.on('end', function () {
    if (backlog) {
      stream.emit('line', backlog)
    }
  })
}

module.exports = emitLines;