How can I check which version of Apache is installed on a Debian machine?
Is there a command for doing this?
Try apachectl -V:
$ apachectl -V
Server version: Apache/2.2.9 (Unix)
Server built: Sep 18 2008 21:54:05
Server's Module Magic Number: 20051115:15
Server loaded: APR 1.2.7, APR-Util 1.2.7
Compiled using: APR 1.2.7, APR-Util 1.2.7
... etc ...
If it does not work for you, run the command with sudo
.