Now that Ubuntu 20.04 LTS is out, it was time to update my bootable USB drive with a bunch of ISO images. Except I got tired of editing grub.cfg by hand. So I wrote a script. Now all I have to do is plug in my USB drive, download a new ISO into it, run make in the /boot/grub subdirectory, and presto! It works. What the script does: finds all ISO files in .