Further testing suggests that macOS unconditionally replaces the final character with a
`1` (I tested with `kbio02` as the device short name, which became the "Serial Number"
`CDkbio02`, and it got changed to `CDkbio01` in the filename). This change will try
looking for any file that matches the serial number with the final character replaced with
"1" (not just if that charater is "E"). I also added some comments that might help update
the script in the future if the OS changes behaviour.
Several people have reported difficulty flashing firmware on macOS High Sierra because the
device port filename doesn't match the serial number from system_profiler. In particular,
system_profiler would return a string ending in `E` whereas the device filename would have
a `1`. This change adds a check for that filename explictily.
I also corrected the location_id fallback (the substring should have been just 3
characters long, not 4), and it works properly on my system if I make the device shortname
7 characters long, and the filename reverts to using the location id instead.
Last, I added one more check, simply listing the filenames, and searching for a match for
the string `kbio01`, which should be present (although in one case, it wasn't).
Michael Richters