Compressing multiple files using zlib

Question

The below code will compress one file. How can I compress multiple files

var gzip = zlib.createGzip();
var fs = require('fs');
var inp = fs.createReadStream('input.txt');
var out = fs.createWriteStream('input.txt.gz');

inp.pipe(gzip).pipe(out);

Answer 1

Something that you could use:

var listOfFiles = ['firstFile.txt', 'secondFile.txt', 'thirdFile.txt'];

function compressFile(filename, callback) {
    var compress = zlib.createGzip(),
        input = fs.createReadStream(filename),
        output = fs.createWriteStream(filename + '.gz');

    input.pipe(compress).pipe(output);

    if (callback) {
        output.on('end', callback);
    }
}

#1 Method:

// Dummy, just compress the files, no control at all;
listOfFiles.forEach(compressFile);

#2 Method:

// Compress the files in waterfall and run a function in the end if it exists
function getNext(callback) {
    if (listOfFiles.length) {
        compressFile(listOfFiles.shift(), function () {
            getNext(callback);
        });
    } else if (callback) {
        callback();
    }
}

getNext(function () {
    console.log('File compression ended');
});