What is the double dash in this bash script excerpt doing

Question

I\'m looking at an excerpt of bash and I\'m trying to understand what exactly is happening here, particularly in the COMPREPLY assignment:

 case         


        

Answer 1

The double dashes end the argument portion in getopt_long. From the manual.

The special argument "--" forces an end of option-scanning regardless of the scanning mode.

https://linux.die.net/man/3/getopt_long

The double semi colons end a case branch.