Thank you IsaacKuo !!!
That is in keeping with my normal pick and shovel (or BFH) approach to fixing problems
It sort of reminds me of a script I used on my Osborn (CP/M) computer to start Wordstar. Instead of actually starting Wordstar ws<Enter> would execute the script which would:
Start Wordstar (which was patched to look on the B diskette for data files)
Upon exiting from Wordstar it would prompt me to put my backup diskette in the A drive
Use PIP (peripheral interchange program) to backup any new or changed files from the data diskette in B to the backup diskette in A
The music file question is not really critical. I AM looking for little tasks to start building my knowledge and skills in managing systemd. The task I really want to accomplish is to configure my servers to conditionally unlock and mount encrypted file systems IF and ONLY IF a certain USB drive is present and contains the appropriate key file(s). Currently is use /etc/crypttab and /etc/fstab. If the key file is not available the server will not boot. I have a script roughed out to do the conditional unlock/mount but I have no idea how and where to shove it into the systemd universe.
Ken