stackoverflow-sort2.js

// sort2 uses sort-stream, as suggested by Joe Krill
//////////////////////////////////////////////////////////////////////////////////////

var fs = require('fs');
var sort = require('sort-stream');
var parse = require('csv-parse');
var transform = require('stream-transform');

var start = Date.now();

// Create a readble stream from the input file.
var pipe = fs.createReadStream('./input.txt')
    // Use `csv-parse` to parse the input using a tab character (\t) as the
    // delimiter. This produces a record for each row which is an array of
    // field values.
    .pipe(parse({
        delimiter: '\t'
    }))
    // Use `sort-stream` to sort the parsed records on the third field.
    .pipe(sort(function (a, b) {
        return a[2].localeCompare(b[2]);
    }))
    // Use `stream-transform` to transform each record (an array of fields) into
    // a single tab-delimited string to be output to our destination text file.
    .pipe(transform(function (row) {
        return row.join('\t') + '\r';
    }))
    // And finally, output those strings to our destination file.
    .pipe(fs.createWriteStream('./out2.txt'));

pipe.on('finish', function () {
    var closetime = Date.now();
    console.log('Read entirefile. ', (closetime - start)/1000, ' secs');
});