commandline session
$getopt hello -- $getopt helloo -- $getopt hellooo -- $getopt hellooo how -- how $getopt hellooo how are -- how are $getopt h how are -- how are $getopt h h h -- h h $getopt ab -a -a -- $getopt ab -ab -a -b -- $getopt ab -ab -R getopt: invalid option -- 'R' -a -b -- $getopt ab -ab -l getopt: invalid option -- 'l' -a -b -- $getopt ab -abl getopt: invalid option -- 'l' -a -b -- $getopt ab -abn getopt: invalid option -- 'n' -a -b -- $getopt ab -abc getopt: invalid option -- 'c' -a -b -- $getopt nl -nl -n -l -- $getopt R -nl getopt: invalid option -- 'n' getopt: invalid option -- 'l' -- $getopt R -R -R -- $