That was my next step, but I had already spent an afternoon on it, so I ended up just making do without and using grep. (Partly because docker has it's own set

That was my next step, but I had already spent an afternoon on it, so I ended up just making do without and using grep. (Partly because docker has it's own set of obnoxious quirks, as it assumes everything can and should be run as root. And rootless docker cannot coexist on a system with over-permissioned docker. I really need to switch over to podman at some point.)