Cobra is both a library for creating powerful modern CLI applications as well as a program to generate applications and command files.

https://github.com/spf13/cobra

Cobra is a library providing a simple interface to create powerful modern CLI interfaces similar to git & go tools.

Cobra is also an application that will generate your application scaffolding to rapidly develop a Cobra-based application.

Cobra provides:

• Easy subcommand-based CLIs: app server, app fetch, etc.
• Fully POSIX-compliant flags (including short & long versions)
• Nested subcommands
• Global, local and cascading flags
• Easy generation of applications & commands with cobra init appname & cobra add cmdname
• Intelligent suggestions (app srver… did you mean app server?)
• Automatic help generation for commands and flags
• Automatic detailed help for app help [command]
• Automatic help flag recognition of -h, --help, etc.
• Automatically generated bash autocomplete for your application
• Automatically generated man pages for your application
• Command aliases so you can change things without breaking them
• The flexibility to define your own help, usage, etc.
• Optional tight integration with viper for 12-factor apps

Cobra has an exceptionally clean interface and simple design without needless constructors or initialization methods.

Applications built with Cobra commands are designed to be as user-friendly as possible. Flags can be placed before or after the command (as long as a confusing space isn’t provided). Both short and long flags can be used. A command need not even be fully typed. Help is automatically generated and available for the application or for a specific command using either the help command or the --help flag.