Add expires header without mod_expires?

Question

I know that I can add expires header using mod_expires. However, what can I do if the Apache server doesn't have mod_expires installed and I don't want to route the access to the files through a scripting language like PHP?

Answer 1

You could use mod_header to set the header field manually:

Header set Expires "..."

But since Expires requires an absolute time, use Cache-Control’s max-age parameter for times relative to the access time:

Header merge Cache-Control max-age=3600

Answer 2

This should tell the browser to refresh the page on subsequent visits. The expires date just has to be in the past... you could set the date using PHP to make it "just" in the past, or just leave it as the date you found this answer!!!

header("Cache-Control: no-cache, must-revalidate");
header("Expires: Thu, 2 Sep 2010 05:00:00 GMT");

UPDATE: Apologies - I missed the "Don't" in the sentence about routing files through PHP! You can also use these HTML meta tags:

<meta http-equiv="Cache-Control" content="no-cache">
<meta http-equiv="Pragma" content="no-cache">
<meta http-equiv="expires" content="Thu, 2 Sep 2010 05:00:00 GMT">

Answer 3

If you have static Expires headers, the following will add an Expires header to your js and css files:

<FilesMatch "\.(js|css)$">
Header set Expires "Fri, 01 Jan 2010 00:00:00 GMT"
</FilesMatch>