taginfo is a useful audio tag reader that can be used in shell scripts.
The bad thing is it can’t set tags so until now I had to use audiotag to set the tags in my shell scripts.

Today I’ve written a simple tool called envtag while experimenting with taglib’s C bindings.
It’s a lot like taginfo and adds a -s option to set the tags from environment variables.
The README is here if you are interested.