This is a feature I knew about, and one I've found useful. It means I can keep working on a long shell script while the first part is running. The "be careful

This is a feature I knew about, and one I've found useful. It means I can keep working on a long shell script while the first part is running. The "be careful" applies to editing parts of the script that have already run. Bash in general is a really helpful tool because it lets you trade off some safety for the ability to move very quickly, and this kind of on-the-fly editing is a good example.