stackoverflow-sort5.js

// sort5 uses `sort -k3,3`, and process the response sent to stdout  
//////////////////////////////////////////////////////////////////////////////////////
var fs = require('fs'),
    util = require('util'),
    spawn = require('child_process').spawn,
    sort = spawn('sort', ['-k3,3', './input.txt']);

var start = Date.now();

var writer = fs.createWriteStream('out5.txt');

sort.stdout.on('data', function (data) {
    // process data
    data.toString()
        .split('\n')
        .map(line => line.split("\t"))
        .forEach(record => writer.write(record.join('\t') + '\n'));
});

sort.on('exit', function (code) {
    if (code) {
        // handle error
    }
    writer.end();

    var closetime = Date.now();
    console.log('Time. ', (closetime - start) / 1000, ' secs');
});

// optional
sort.stderr.on('data', function (data) {
    // handle error...
    console.log('stderr: ' + data);
});