It's easy to add a few lines of text to files on Linux, but there are tools that make it easier to add many lines.

You could even embed an executable file in a script — even another script — and then execute that script which might unpack another script. It boggles the mind.

If nano is your Linux editor of choice, and you want to make it a bit more flexible, Jack Wallen is ready to help you with the built-in Execute tool.