simple exec sync in nodejs

execSync

var fs = require('fs');
var exec = require('child_process').exec;

/**
 * execSync
 *
 * simple version of execSync
 * refer to 'shelljs -> exec', https://github.com/arturadib/shelljs/blob/master/src/exec.js
 * @param  {String} cmd 
 * @param {Object} option
 */
function execSync(cmd, option) {
    var timestamp = new Date().getTime(),
        outFile = '/tmp/exec_sync_out_' + timestamp,
        errFile = '/tmp/exec_sync_err_' + timestamp,
        doneFile = '/tmp/exec_sync_done_' + timestamp,
        sleepFile = '/tmp/exec_sync_sleep_' + timestamp;

    exec(cmd + ' 2> ' + errFile + ' 1> ' + outFile + '; echo $? > ' + doneFile, option);

    // block and wait child process done
    while (!fs.existsSync(doneFile)) {
        // reduce cpu usage
        fs.writeFileSync(sleepFile, 'a');
    }

    var code = fs.readFileSync(doneFile, {'encoding': 'utf8'}),
        stdout = fs.readFileSync(outFile, {'encoding': 'utf8'}),
        stderr = fs.readFileSync(errFile, {'encoding': 'utf8'});

    fs.unlinkSync(doneFile);
    fs.unlinkSync(outFile);
    fs.unlinkSync(errFile);
    fs.unlinkSync(sleepFile);

    return {
        code: code ? parseInt(code) : 0,
        stdout: stdout,
        stderr: stderr
    };
}