Find and Head with Node.js

find.js

function scanDirStream(needle, params) {
    var options = {
        // find -type
        type: 'f',
        // find -name
        name: '*',
        limit: 100
    };
    for (var attrname in params) { options[attrname] = params[attrname]; }
    return new Promise((resolve, reject) => {
        var opt = [needle];
        for (var k in options) {
            var v = options[k];
            if (!Util.empty(v) && k != 'limit') {
                opt.push('-' + k);
                opt.push(v);
            }
        };
        var res = '';
        console.log(opt)
        var find = spawn('find', opt);
        var head = spawn('head',[ '-n', options.limit]);
        find.stdout.pipe(head.stdin);
        head.stdout.on('data', _data => {
            var buff = Buffer.from(_data, 'utf-8').toString();
            if (buff != '') res += buff;
        })
        head.stderr.on('data', error => {
            return reject(Buffer.from(error, 'utf-8').toString());
        });
        head.on('close', (_) => {
            data = res.split('\n');
            data = data.slice(0, data.length - 1);
            return resolve(data);
        });
    });
}//scanDirStream