Working with JSON using Node.js, Streams, and the Unix command line

process_customers.js

// Usage:
// cat customers_raw.json | node process_customers > customers.json

// https://github.com/dominictarr/JSONStream
var JSONStream = require('JSONStream');
// https://github.com/rvagg/through2
var through2 = require('through2');

process.stdin
.pipe(JSONStream.parse('*'))
.pipe(through2({objectMode: true}, function(data, encoding, callback) {
  // Do something cool with the `data` object
  this.push(data)
  callback();
}))
.pipe(JSONStream.stringify('[\n', ',\n', '\n]\n'))
.pipe(process.stdout);

// If we use `head` downstream it will send an error signal
process.stdout.on('error', process.exit);

// Also check out command line tool json(1):
// http://trentm.com/json