build in getopts function, instead of the external getopt program.
This would reduce an external dependency, which would definitely be
better for portability.
+
+---
+
+So it looks like the sh built-in getopts does not include long options
+(eg. "--expire"). Is it worth getting rid of the long options for
+this?
+
+---
+
+Why not just get rid of getopts altogether and perform a simple
+argument-processing loop with bash string tests? We're only invoking
+getopt in three places, and each invocation is no more complex than
+three arguments -- and most arguments take a separate parameter, which
+means that handling tricky arg blobs like -aCxr are not gonna be
+supported anyway.