Request: filter/highlight regex-matched entries

[kylemallory]

I'd like the ability to filter journalctl entries which match a regex expression. For example, if I wanted to see failed login attempts on the ssh.service for a particular IP address, or ERROR level messages from a web service.

As many browsers can highlight "found occurances", this would only be a nice-to-have, but I think could be a useful feature.

Ideally, you could specify multiple patterns, with the ability to toggle individual patterns or delete them. Tied to a user/role management system, "default" or enforced patterns could be applied to specific individuals/roles.