|The Apache HTTP Server Reference Manual
by Apache Software Foundation
Paperback (6"x9"), 862 pages
RRP £19.95 ($29.95)
mod_authz_host, in conjunction with mod_setenvif, can be used to restrict access to your website based on the value of arbitrary environment variables. This is done with the Allow from env= and Deny from env= syntax.
SetEnvIf User-Agent BadBot GoAway=1
Allow from all
Deny from env=GoAway
Warning: Access control by User-Agent is an unreliable technique, since the User-Agent header can be set to anything at all, at the whim of the end user.
In the above example, the environment variable GoAway is set to 1 if the User-Agent matches the string BadBot. Then we deny access for any request when this variable is set. This blocks that particular user agent from the site.
An environment variable test can be negated using the =! syntax:
Allow from env=!GoAway
|ISBN 9781906966034||The Apache HTTP Server Reference Manual||See the print edition|