Re: Caching Servers Considered Harmful (was: Re: Finger URL)

John Labovitz (
Mon, 22 Aug 1994 22:22:50 +0200

[Martijn Koster <>]
> Just wondering -- do you specify a Expired header for that file,
> indicating it expires daily? If so any cache that doesn't honour it is
> broken. If you don't, then what do you expect?

I just looked through the NCSA httpd source code and found
no way to specify an Expires: header for a file. If this
was a CGI script, I know I could add one myself, but how
do I tell the server to send an Expires: header for an
ordinary HTML or GIF file?

I realize this is getting off track, but it'd be nice to
be able to specify HTTP headers for random files. For the
Unix environment, perhaps file `foo.html' could have an
associated `foo.html.hdr' file that the HTTP server knows
to look for, and adds any headers found there (like Expires).
This would also be a solution to the problem of moved files
-- if I rename `foo.html' to `bar.html', then `foo.html.hdr'
could contain `Location: bar.html' (is that right?), without
having to modify httpd's config file.

John Labovitz
Global Network Navigator <>
O'Reilly & Associates, Sebastopol, California, USA (+1 707 829 0515)