The `elgetopt` program

elgetopt performs getopt-style parsing on the arguments to an execline script.

Interface

     elgetopt [ -D default ] optstring prog...

elgetopt expects to find a valid number n of arguments in the # environment variable, and n+1 environment variables 0, 1, ..., n. It exits 100 if it is not the case.
elgetopt pushes environment variables starting with ELGETOPT_. To get the previous values back, use emptyenv -o.
elgetopt looks into 1, 2... for options, as specified by optstring, which is a standard getopt string.
If the -c switch is recognized, elgetopt sets the ELGETOPT_c environment variable. The value of that variable is the argument to the -c switch if it has one, and 1 (or default if given) otherwise.
After setting all recognized options, elgetopt makes new #, 1, 2... "positional parameters" with what remains.
elgetopt then execs into prog....

-D default : use default as the value for the ELGETOPT_c environment variable if there is no argument to the -c switch. Default is 1. The value is the same for all the options defined by elgetopt.