Package flags provides an extensive command line option parser. The flags package is similar in functionality to the go builtin flag package but provides more options and uses reflection to provide a convenient and succinct way of specifying command line options. Supported features: The flags package uses structs, reflection and struct field tags to allow users to specify command line options. This results in very simple and consise specification of your application options. For example: This specifies one option with a short name -v and a long name --verbose. When either -v or --verbose is found on the command line, a 'true' value will be appended to the Verbose field. e.g. when specifying -vvv, the resulting value of Verbose will be {[true, true, true]}. Slice options work exactly the same as primitive type options, except that whenever the option is encountered, a value is appended to the slice. Map options from string to primitive type are also supported. On the command line, you specify the value for such an option as key:value. For example Then, the AuthorInfo map can be filled with something like -a name:Jesse -a "surname:van den Kieboom". Available field tags: Either short: or long: must be specified to make the field eligible as an option.