Deleting lines in a file from configuration files with editfiles

[Berthold Cogel]

Hello!

I'm looking for a method to delete lines that I can not describe with a 
string or a regex in a cfengine script.

For example:

I want to edit root's authorized_keys file. I want to distribute ssh 
public keys with cfengine. It is not a problem to collect the keys and 
append them to authorized_keys. But I would also like to revoke keys by 
distributing them in a single file.

I need something like 'DeleteLinesMatchingFromFile', 
'DeleteLinesContainingFileItems' or 'Delete "ThisLine".

Of course I can rebuild the file from scratch with cfengine. But there 
are situations where I don't want to do this.

Regards,

Berthold