[tlug] Web Page Caching: Timestamps, HTTP+HTML,touch (Re: Website Update Prompt -II)

[Jim <jep200404@example.com>]

Lyle wrote:

> Re: [Jim] Also understand that not just HTML is in play. HTTP is also
> involved. Feast your eyes on this:
> 
>    wget -S -O /dev/null http://www5d.biglobe.ne.jp/~LLLtrs/

>   Date: Tue, 24 Jan 2006 04:41:56 GMT

>   Last-Modified: Tue, 13 Dec 2005 07:39:27 GMT

> This raises a question - it shows that it was last modified on
> December 13th, 2005.  Where did that information come from?

Bingo! That's the right question and there will be more. 
Welcome to HTTP. Explore. Enjoy the ride. 
This is in addition to the HTML. 

Also, learn the "touch" command. If you are messing around with 
file timestamps, how to you restore an old version of a file 
with the old timestamp? 

   cp -p
   mv
   tar (backup and restore)

The "make" command relies on file timestamps.