Hey Costa,
That's simple, although you might not think so if you're unfamiliar with regular expressions. (See macro below.)
I could have used one Search Variable action to extract each tag-block, but I broke it up into six actions – so the regular expressions would be easier to understand.
This gives you an example of how to pull text out of a text file and parse it into different variables.
(The variables are deleted at the beginning and end of the macro to prevent them from accidentally being reused – in a production macro I'd add more error-checking.)
I'm not familiar with any command-line MP3 tagging software, but Google unsurprisingly says some exist.
I found this pretty quickly on Stackexchange: Is there a good command-line ID3 tool for OS X?
I was able to install id3lib using MacPorts (I use it instead of Homebrew).
It did install id3tag.
There's not a man page for it, but there is help: id3tag -h
-Chris
