addEventListener("fetch", (event) => {
  event.respondWith(
    doRedirects(event.request).catch(
      // catch error with a trace of which functions were called, in what order, from which line and file, and with what arguments
      (err) => new Response(err.stack, { status: 500 })
    )
  );
});

// final redirect destination
const newLocationHost = "developers.cloudflare.com";

async function doRedirects(request) {
  // get user-agent header
  let reqUA = request.headers.get('user-agent')
  
  // match method that accepts a regular expression
  const regexcurl = /curl[\s\S]*/;
  if (reqUA !== null && reqUA.match(regexcurl)) {

    // new location through HTTPS
    let newLocation = "https://"+newLocationHost

    //return Response.redirect(newLocation, 302);
    // return redirect
    return new Response(undefined, {
      status: 302,
      statusText: 'Found',
      headers: {
        Location: newLocation
      }
    });
  }
return fetch(request);
}