Concatenate files with node.js

fjoin.js

/* USAGE:
node fjoin file1 file2 file 3
or
fjoin({files, target}) 
*/

var util = require('util'),
    fs = require('fs'),
    files = [],
    readstream,
    i = 1;

var streamFile = function (stream) {
    var file = files.shift();

    readstream = fs.createReadStream(file, {encoding: 'utf-8'});

    readstream.on('end', function () {
        if (files.length) {
            streamFile(stream);
            i += 1;
        } else {
            stream.end();
            console.log('All done,', i, 'files joined.');
        }
    });

    readstream.pipe(stream, { end: false });
};


var fjoin = function (options, config) {
    var newFile = fs.createWriteStream(options.target),
        args = process.argv.slice(2, process.argv.length);

    files = args.length ? args : options.files.slice(0);

    if (files.length) streamFile(newFile);
};

fjoin({
    files: ['text.txt', 'text.txt'],
    target: 'final.txt'
});

exports.fjoin = fjoin;