respawn.js

var fs      = require('fs'),
    cfg     = JSON.parse(fs.readFileSync('respawn.json', { encoding: 'utf8' })),
    now     = new Date(),
    t_stamp = now.getFullYear()    + '-' +
              (now.getMonth() + 1) + '-' +
              now.getDate();



function copy(source, target) {
    fs.createReadStream(source).pipe(fs.createWriteStream(target));
}


function echo(msg, indent) {

    indent = indent || 1;

    console.log(Array(indent + 1).join('\t') + msg);
}


function maybe_add_ts(path) {

    return cfg.add_timestamp === true ?
            path + ' ' + t_stamp :
            path;
}

function prepare_backup_dir(path) {

    if (!fs.existsSync(path)) {
        fs.mkdirSync(path);
    }
}



echo('\n\tStarting backups!\n\n');

cfg.targets.forEach(function (target) {

    var backup_dir = cfg.backup_root_dir + target.backup_subdir,
        filenames;

    backup_dir = maybe_add_ts(backup_dir);
    prepare_backup_dir(backup_dir);

    echo('Backing up ' + target.source_dir + ' to ' + backup_dir + '...\n');

    filenames = fs.readdirSync(target.source_dir).filter(function (name) {
        var extMatch = name.match(/.+\.(.+)/);
        return extMatch !== null && 
               target.extension_blacklist.indexOf(extMatch[1]) === -1;
    });

    filenames.forEach(function (filename) {
        var file_to_copy = target.source_dir + '\\' + filename,
            target_path  = backup_dir  + '\\' + filename;

        echo(file_to_copy + ' -> ' + target_path, 2);
        copy(file_to_copy, target_path);

        target.alternative_backup_dirs.forEach(function (alternative) {

            alternative = maybe_add_ts(alternative);
            prepare_backup_dir(alternative);

            alternative += '\\' + filename;

            echo(file_to_copy + ' -> ' + alternative + ' (alternative)', 3);
            copy(file_to_copy, alternative);
        });
    });

    echo('\n\n\tDone.\n');
});

respawn.json

{
    "backup_root_dir": "C:\\",
    "targets":     [
        {
            "source_dir":              ".",
            "backup_subdir":           "spawn",
            "alternative_backup_dirs": [
                "C:\\spawn2",
                "C:\\spawn3"
            ],
            "extension_blacklist":     [
                "xlsx", "txt"
            ]
        }
    ],

    "add_timestamp": true
}