 | It is a ``standard'' to use either short or long options
-d dir # short options -d and -h --directory dir # long options --directory and --help |
| Short options have single hyphen, long options have double hyphen |
| Options can take a value or not:
--directory dir --help --confirm -d dir -h -i |
| Short options can be combined
-iddir is the same as -i -d dir |
