go-flags

go-flags: a go library for parsing command line arguments

This library provides similar functionality to the builtin flag library of go, but provides much more functionality and nicer formatting. From the documentation:

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:

• Options with short names (-v)
• Options with long names (--verbose)
• Options with and without arguments (bool v.s. other type)
• Options with optional arguments and default values
• Multiple option groups each containing a set of options
• Generate and print well-formatted help message
• Passing remaining command line arguments after -- (optional)
• Ignoring unknown command line options (optional)
• Supports -I/usr/include -I=/usr/include -I /usr/include option argument specification
• Supports multiple short options -aux
• Supports all primitive go types (string, int{8..64}, uint{8..64}, float)
• Supports same option multiple times (can store in slice or last option counts)
• Supports maps
• Supports function callbacks
• Supports namespaces for (nested) option groups

The flags package uses structs, reflection and struct field tags to allow users to specify command line options. This results in very simple and concise specification of your application options. For example:

type Options struct {
	Verbose []bool `short:"v" long:"verbose" description:"Show verbose debug information"`
}

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]}.

Example:

…

More information can be found in the godocs: http://godoc.org/github.com/jessevdk/go-flags