Label processes based on a regexp over ARGV

[hillu]

I have been asked about using the proceess labeling feature based on not only the executable but on the argument list.

I currently see practical implementation problems with this: The regexp engine from the regex crate has the nice feature of providing a multi-pattern matcher. However, it can only work on fixed buffers, not on input streams that are constructed as they are fed to the matcher. So we'd have to copy every argument list before matching, resulting in (I fear) considerable CPU and memory overhead even before the matcher gets to run. I am not aware of an alternative regexp implementation that could be used instead.

This issue needs some more thinking about.

Concrete use-cases of process invocations would certainly be useful, please add them in the comments.