Re: Howto: Retrieve only URL metadata

[Adam Porter]

> Is there a light-weight means of just retrieving URL metadata given a
> URL using the url package in Emacs?
>
> Note: I know how to do that using Curl and parsing the output from a
> HEAD method call; am looking for a pure elisp solution

FYI, if you'll forgive the transgression, since plz.el is in ELPA and 
"part of Emacs", here's a simple way to do it:

  (plz-response-headers
   (plz 'head 
"https://lists.gnu.org/archive/html/emacs-devel/2024-03/msg00670.html";
     :as 'response))

  ;; ((date . "Wed, 27 Mar 2024 04:11:27 GMT")
  ;;  (server . "Apache/2.4.29 (Trisquel_GNU/Linux)")
  ;;  (strict-transport-security . "max-age=63072000; 
includeSubDomains; preload")
  ;;  (x-frame-options . "sameorigin")
  ;;  (x-content-type-options . "nosniff")
  ;;  (last-modified . "Wed, 27 Mar 2024 03:44:54 GMT")
  ;;  (etag . "\"1472-6149c3ac97980-gzip\"")
  ;;  (accept-ranges . "bytes")
  ;;  (vary . "Accept-Encoding")
  ;;  (content-encoding . "gzip")
  ;;  (content-length . "2022")
  ;;  (content-type . "text/html"))

A future version will probably simplify that, returning the alist of 
headers directly for calling:

  (plz 'head URL)