Thanks for putting this out for public benefit! I haven’t messed around with MacOS much but the things you’ve mentioned are nice to know.
I believe that’s a shell/bash standard variable, but I need to learn where it came from and how it works
You may know this already, but I’ve found the man (as in manual) utility to be one of the most useful things in GNU/Linux user space. I don’t have much insight into ‘${file##*/}’ off the cuff, but I can tell you there’s manual entries for file, sh, and bash that may help you track it down.
<span style="font-style:italic;color:#969896;"># simply type man [some-command]
</span><span style="color:#323232;">man file
</span><span style="color:#323232;">man sh
</span><span style="color:#323232;">man bash
</span><span style="color:#323232;">man man </span><span style="font-style:italic;color:#969896;"># very useful for getting started!
</span>
Manpages are local to your system so they’re extremely fast to pull up and searchable!
Here’s some online info on man if you’re interested: