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stream-eachline Build Status

Like readline or split, but behaves more like ruby's .each_with_index method when streams lack trailing newlines.

Getting Started

Install the module with: npm install stream-eachline

var eachline = require('stream-eachline').eachline;
// Modify each line in process.stdin input stream (while streaming) 
// and when done log an array of modified lines. 
eachline(process.stdin, function(line, index) {
  return '[' + index + '' + line.toUpperCase();
}, function(lines) {
  console.log('Array of modified lines:', lines);
// The following examples all do the same thing: 
eachline(process.stdin, function(line, index) {
  return line;
}, function(lines) {
// You may omit lineFunction if you don't need to modify the streamed lines. 
eachline(process.stdin, doSomethingWithLines);
// You may omit instream if you want to process process.stdin's lines. 


eachline([instream], [lineFunction], doneFunction)

Why this library?

# I couldn't get readline to give me the last line of a stream if there
# was no trailing newline.
$ echo -en 'foo\nbar\nbaz\n' | node examples/readline-broken.js
[ '[0] <foo>', '[1] <bar>', '[2] <baz>' ]
$ echo -en 'foo\nbar\nbaz' | node examples/readline-broken.js
[ '[0] <foo>', '[1] <bar>' ]
# This is the behavior I expected, based on my experience with ruby's
# STDIN.each_with_index method.
$ echo -en 'foo\nbar\nbaz\n' | ruby examples/each-with-index.rb
["[0] <foo>", "[1] <bar>", "[2] <baz>"]
$ echo -en 'foo\nbar\nbaz' | ruby examples/each-with-index.rb
["[0] <foo>", "[1] <bar>", "[2] <baz>"]
# This lib behaves more like ruby's STDIN.each_with_index method.
$ echo -en 'foo\nbar\nbaz\n' | node examples/eachline-yay.js
[ '[0] <foo>', '[1] <bar>', '[2] <baz>' ]
$ echo -en 'foo\nbar\nbaz' | node examples/eachline-yay.js
[ '[0] <foo>', '[1] <bar>', '[2] <baz>' ]


In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using Grunt.

Release History

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Copyright (c) 2014 "Cowboy" Ben Alman
Licensed under the MIT license.