Function readFileFirstLine

src/utilities/get-interpreter.js:8–17

* @param {string | URL} file * @returns {string | undefined}

(file)

 * @returns {string | undefined}
 */
function readFileFirstLine(file) {
  const liner = new readlines(toPath(file));
  const firstLineBuffer = liner.next();

  if (typeof liner.fd === "number") {
    liner.close();
  }

  return firstLineBuffer?.toString("utf8");
}

/**
 * @param {string | URL} file