function readFileSync(filename) {
  const path = require("path"),
    fs = require("fs");
  try {
    //let p = path.join(__dirname, filename);
    let str = fs.readFileSync(filename, "utf8");
    // let str = fs.readFileSync(p, {encoding: 'utf8'});
    console.log(str);
    return str;
  } catch (e) {
    console.error(e.message);
    return null;
  }
}
Read txt file (SyncMode)
@param filename - absolute path to file
@returns {null|string}