I would like to know if there is a way to read log messages from all nodes as the occur? For example to scan for a keyword or count the number of warnings or similar use cases.

I understand that it would be an option to change the appropriate roscomm sources and recompile but I don't even know where to start looking for the right place to change. Another option would be to scan the folders of logfiles but this sounds very inefficient.

Has anyone any ideas?

Has anyone done this before and / or can point me in the right direction?