[jmholla]

I've shared this before, but this sed tutorial made me a pro. [0] Even if you don't use it for more complex things, you may find there are faster ways to do the things you are now.

[0]: https://www.grymoire.com/Unix/Sed.html

Edit: That said, I don't even want to start dissecting the submitted code.

[DryLabRebel]

Grymoire is how I learned sed, and is a fantastic quick reference for grep and regex also.