htaccess doesn't stop this agent

i thought this would stop it

[incywincy]

could any of you htaccess experts help?

i'm getting this agent in my logs and want to stop it.

access_log fragment:
68.97.85.241 - - [02/Jan/2003:20:23:19 +0000] "GET / HTTP/1.1" 200 16353 "-" "Mozilla/4.0 (compatible; grub-client-1.0.6; Crawl your own stuff with [grub.org)"...]
213.51.142.55 - - [03/Jan/2003:05:10:32 +0000] "GET /index.html HTTP/1.1" 200 16360 "-" "Mozilla/4.0 (compatible; grub-client-1.0.6; Crawl your own stuff with [grub.org)"...]

.htaccess fragment:

RewriteCond %{HTTP_USER_AGENT} ^grub [OR]
etc etc

why doesn't this work?

thanks in advance...

[jdMorgan]

RewriteCond %{HTTP_USER_AGENT} ^grub [OR]
etc etc

why doesn't this work?

It doesn't work because the user agent does not begin with "grub", it begins with "Mozilla". The start anchor "^" means the pattern should match anything starting with "grub".

In order to block "Mozilla/4.0 (compatible; grub-client-1.0.6; Crawl your own stuff with [grub.org)"...]

You could use:

RewriteCond %{HTTP_USER_AGENT} ^Mozilla/4\.0\ \(compatible\;\ grub [OR]

or, leave the start anchor off, and use:

RewriteCond %{HTTP_USER_AGENT} grub [OR]

Here's a concise Regular Expressions tutorial [etext.lib.virginia.edu] for more info.

HTH,
Jim

[incywincy]

thankyou very much.

time to brush up on regular expressions!

[jdMorgan]

You're welcome...

After the brushup on regex start and end anchors, you may want to check through your block list and make sure it's doing what you expect - those stray anchors can mess things up. If you know the user agent starts and/or ends with a particular string, use the anchors - they can speed up the compare measurably. If not, leave them off until you've actually caught a sample, then refine the pattern and add anchors for a more efficient match.

For those who haven't seen it yet, one of our forum hosts, DaveAtIFG, did a bang-up job on this Introduction to mod_rewrite [webmasterworld.com].

Jim