/etc/logcheck/ignore.d.workstation/kdm is in logcheck-database 1.3.17.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | ^\w{3} [ :0-9]{11} [._[:alnum:]-]+ kdm: :0\[[0-9]+\]: \(pam_[[:alnum:]]+\) session opened for user [[:alnum:]-]+ by \(uid=[0-9]+\)$
^\w{3} [ :0-9]{11} [._[:alnum:]-]+ kdm: :0\[[0-9]+\]: \(pam_[[:alnum:]]+\) session closed for user [[:alnum:]-]+$
^\w{3} [ :0-9]{11} [._[:alnum:]-]+ kdm: :0\[[0-9]+\]: pam_[[:alnum:]]+\(kdm:session\): session opened for user [[:alnum:]-]+ by \(uid=[0-9]+\)$
^\w{3} [ :0-9]{11} [._[:alnum:]-]+ kdm: :0\[[0-9]+\]: pam_[[:alnum:]]+\(kdm:session\): session closed for user [[:alnum:]-]+$
^\w{3} [ :0-9]{11} [._[:alnum:]-]+ kdm_greet\[[0-9]+\]: Can't open default user face$
|