# Obtaining metadata from a url or web to for avoid loadit **URL:** \ **Category:** Ruby\ **Created:** [September 20, 2010, 4:16pm UTC](https://www.ruby-forum.com/t/obtaining-metadata-from-a-url-or-web-to-for-avoid-loadit/195253 "2010-09-20T16:16:48Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![saknarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f475e1/32.png) [@saknarede](https://www.ruby-forum.com/u/saknarede)\ **Post date:** [September 20, 2010, 4:16pm UTC](https://www.ruby-forum.com/t/obtaining-metadata-from-a-url-or-web-to-for-avoid-loadit/195253/1 "2010-09-20T16:16:48Z")
Hi! I was googling a lot with very different queris to find an answer, lets see: I’m programming a script who work with web files (html and rss), the program check if exists modifications in tons of urls. It was wondering if I could check the data modification (like a local file) to avoid to download the file and load to memory (for compare with cached files) if the file didn’t change. The question is: are there a method to know the modified date (or other metada) of a file from the url? I hope the question was clear and tanks for your time. ---
**Author:** ![saknarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f475e1/32.png) [@saknarede](https://www.ruby-forum.com/u/saknarede)\ **Post date:** [September 20, 2010, 4:23pm UTC](https://www.ruby-forum.com/t/obtaining-metadata-from-a-url-or-web-to-for-avoid-loadit/195253/2 "2010-09-20T16:23:28Z")
On Mon, Sep 20, 2010 at 7:16 AM, Sak … [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > The question is: are there a method to know the modified date (or other > metada) of a file from the url? See the request methods section of [http://www.w3.org/Protocols/rfc2616/rfc2616.html](http://www.w3.org/Protocols/rfc2616/rfc2616.html) ---
**Author:** ![saknarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f475e1/32.png) [@saknarede](https://www.ruby-forum.com/u/saknarede)\ **Post date:** [September 20, 2010, 10:26pm UTC](https://www.ruby-forum.com/t/obtaining-metadata-from-a-url-or-web-to-for-avoid-loadit/195253/3 "2010-09-20T22:26:55Z")
Hassan S. wrote: > On Mon, Sep 20, 2010 at 7:16 AM, Sak … [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > The question is: are there a method to know the modified date (or other > > metada) of a file from the url? > > See the request methods section of > > [http://www.w3.org/Protocols/rfc2616/rfc2616.html](http://www.w3.org/Protocols/rfc2616/rfc2616.html) Thanks for the info, but I can’t find anything about the question. ---
**Author:** ![saknarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f475e1/32.png) [@saknarede](https://www.ruby-forum.com/u/saknarede)\ **Post date:** [September 20, 2010, 10:52pm UTC](https://www.ruby-forum.com/t/obtaining-metadata-from-a-url-or-web-to-for-avoid-loadit/195253/4 "2010-09-20T22:52:48Z")
On Mon, Sep 20, 2010 at 1:26 PM, Sak … [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > See the request methods section of > > > > [http://www.w3.org/Protocols/rfc2616/rfc2616.html](http://www.w3.org/Protocols/rfc2616/rfc2616.html) > > Thanks for the info, but I can’t find anything about the question. 9.4 HEAD The HEAD method is identical to GET except that the server MUST NOT return a message-body in the response. The metainformation contained in the HTTP headers in response to a HEAD request SHOULD be identical to the information sent in response to a GET request. This method can be used for obtaining metainformation about the entity implied by the request without transferring the entity-body itself. This method is often used for testing hypertext links for validity, accessibility, and recent modification. Also, 13.3.1 Last-Modified Dates