Go to file
Ville Skyttä badcce14f8
style(bash-v2): various cleanups (#1702)
* use arithmetic evaluation in numeric context

* remove unnecessary $ from array index variables

* [[ ]] over [ ], == over =, remove unnecessary quoting

* use ${foo-} rather than ${foo:-} in emptiness check

The result of the expansion is null no matter if the variable is unset
or null in both cases; the former form is arguably easier on the eye.

* remove unnecessary trailing linefeed removal

No longer needed as of f464d6c82e, saves
a subshell.

* use herestring in activehelp extraction

Herestrings read cleaner than process substitutions, and work in posix
mode (but we do and will have some process substitutions so this doesn't
matter much). Both approaches may end up using temporary files.
2022-10-17 15:24:27 -04:00
.github ci: add minimum GitHub token permissions for workflows (#1792) 2022-10-03 08:53:12 -06:00
doc feat: make InitDefaultCompletionCmd public (#1467) 2022-10-10 19:06:30 -04:00
.gitignore leverage makefile to run build tasks (#976) 2020-02-20 12:25:38 -07:00
.golangci.yml add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
.mailmap Add .mailcap for a more tidy "git shortlog" output 2015-11-20 15:24:23 -07:00
active_help_test.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
active_help.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
active_help.md Add Active Help support (#1482) 2022-06-15 20:08:16 -04:00
args_test.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
args.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
bash_completions_test.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
bash_completions.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
bash_completions.md Bash completion V2 with completion descriptions (#1146) 2021-06-30 15:24:58 -06:00
bash_completionsV2_test.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
bash_completionsV2.go style(bash-v2): various cleanups (#1702) 2022-10-17 15:24:27 -04:00
cobra_test.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
cobra.go Add OnFinalize method (#1788) 2022-10-03 08:52:50 -06:00
command_notwin.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
command_test.go Add groups for commands in help (#1003) 2022-10-10 14:59:11 -06:00
command_win.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
command.go feat: make InitDefaultCompletionCmd public (#1467) 2022-10-10 19:06:30 -04:00
completions_test.go Include --help and --version flag in completion (#1813) 2022-10-04 16:41:30 -06:00
completions.go feat: make InitDefaultCompletionCmd public (#1467) 2022-10-10 19:06:30 -04:00
CONDUCT.md Cobra User Contract (#1292) 2021-01-26 10:55:24 -07:00
CONTRIBUTING.md Add CONTRIBUTING.md (#1183) 2020-08-10 22:14:21 -06:00
fish_completions_test.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
fish_completions.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
fish_completions.md Extend Go completions and revamp zsh comp (#1070) (#1070) 2020-06-29 13:52:14 -06:00
flag_groups_test.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
flag_groups.go Expose ValidateRequiredFlags and ValidateFlagGroups (#1760) 2022-09-27 06:27:48 -04:00
go.mod Update gopkg.in/yaml.v2 to gopkg.in/yaml.v3 (#1766) 2022-08-13 16:18:46 -06:00
go.sum Update gopkg.in/yaml.v2 to gopkg.in/yaml.v3 (#1766) 2022-08-13 16:18:46 -06:00
LICENSE.txt adding license 2013-09-03 18:46:13 -04:00
MAINTAINERS Add MAINTAINERS file (alphabetical order) (#1545) 2022-02-28 08:24:45 -07:00
Makefile With go 1.18, we must use go install for a binary (#1726) 2022-08-30 08:34:58 -06:00
powershell_completions_test.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
powershell_completions.go Allow user to add completion for powershell alias (#1621) 2022-10-03 13:06:04 -04:00
powershell_completions.md powershell completion with custom comp (#1208) 2020-12-29 07:57:32 -07:00
projects_using_cobra.md Add Constellation to projects using cobra. (#1829) 2022-10-13 09:47:58 -04:00
README.md Add groups for commands in help (#1003) 2022-10-10 14:59:11 -06:00
shell_completions.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
shell_completions.md Allow user to add completion for powershell alias (#1621) 2022-10-03 13:06:04 -04:00
user_guide.md Add groups for commands in help (#1003) 2022-10-10 14:59:11 -06:00
zsh_completions_test.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
zsh_completions.go add missing license headers (#1809) 2022-09-16 07:55:56 -04:00
zsh_completions.md Improve zsh completion documentation (#1169) 2020-07-19 16:02:46 -06:00

cobra logo

Cobra is a library for creating powerful modern CLI applications.

Cobra is used in many Go projects such as Kubernetes, Hugo, and GitHub CLI to name a few. This list contains a more extensive list of projects using Cobra.

Go Reference Go Report Card Slack

Overview

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

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
  • Intelligent suggestions (app srver... did you mean app server?)
  • Automatic help generation for commands and flags
  • Grouping help for subcommands
  • Automatic help flag recognition of -h, --help, etc.
  • Automatically generated shell autocomplete for your application (bash, zsh, fish, powershell)
  • 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 seamless integration with viper for 12-factor apps

Concepts

Cobra is built on a structure of commands, arguments & flags.

Commands represent actions, Args are things and Flags are modifiers for those actions.

The best applications read like sentences when used, and as a result, users intuitively know how to interact with them.

The pattern to follow is APPNAME VERB NOUN --ADJECTIVE or APPNAME COMMAND ARG --FLAG.

A few good real world examples may better illustrate this point.

In the following example, 'server' is a command, and 'port' is a flag:

hugo server --port=1313

In this command we are telling Git to clone the url bare.

git clone URL --bare

Commands

Command is the central point of the application. Each interaction that the application supports will be contained in a Command. A command can have children commands and optionally run an action.

In the example above, 'server' is the command.

More about cobra.Command

Flags

A flag is a way to modify the behavior of a command. Cobra supports fully POSIX-compliant flags as well as the Go flag package. A Cobra command can define flags that persist through to children commands and flags that are only available to that command.

In the example above, 'port' is the flag.

Flag functionality is provided by the pflag library, a fork of the flag standard library which maintains the same interface while adding POSIX compliance.

Installing

Using Cobra is easy. First, use go get to install the latest version of the library.

go get -u github.com/spf13/cobra@latest

Next, include Cobra in your application:

import "github.com/spf13/cobra"

Usage

cobra-cli is a command line program to generate cobra applications and command files. It will bootstrap your application scaffolding to rapidly develop a Cobra-based application. It is the easiest way to incorporate Cobra into your application.

It can be installed by running:

go install github.com/spf13/cobra-cli@latest

For complete details on using the Cobra-CLI generator, please read The Cobra Generator README

For complete details on using the Cobra library, please read the The Cobra User Guide.

License

Cobra is released under the Apache 2.0 license. See LICENSE.txt