> ./getoptdemo -ab arg1 -dc
-ab arg1 -dc
result for ":ab:c:":
optind=01 -a
optind=03 -b arg1
optind=03 -d [unknown option]
optind=04 -c [need an argument]
result for "ab:c:":
optind=01 -a
optind=03 -b arg1
optind=03 -d [unknown option]
optind=04 -c [unknown option]