Obtaining metadata from a url or web to for avoid loadit

Ruby
1

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.

2

On Mon, Sep 20, 2010 at 7:16 AM, Sak … [email protected] 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

3

Hassan S. wrote:

On Mon, Sep 20, 2010 at 7:16 AM, Sak … [email protected] 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

Thanks for the info, but I can’t find anything about the question.

4

On Mon, Sep 20, 2010 at 1:26 PM, Sak … [email protected] wrote:

See the request methods section of

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