Add groups for commands in help

Adds the possibility to group the commands in the help message.

README.md

@@ -550,6 +550,11 @@ command and flag definitions are needed.
 Help is just a command like any other. There is no special logic or behavior
 around it. In fact, you can provide your own if you want.
 
+### Grouping commands in help
+
+Cobra supports grouping of available commands. Groups can either be explicitly defined by `AddGroup` and set by
+the `Group` element of a subcommand. If Groups are not explicitly defined they are implicitly defined.
+
 ### Defining your own help
 
 You can provide your own Help command or your own template for the default command to use

command.go

@@ -33,6 +33,12 @@ var ErrSubCommandRequired = errors.New("subcommand is required")
 // FParseErrWhitelist configures Flag parse errors to be ignored
 type FParseErrWhitelist flag.ParseErrorsWhitelist
 
+// Structure to manage groups for commands
+type Group struct {
+	Group string
+	Title string
+}
+
 // Command is just that, a command for your application.
 // E.g.  'go run ...' - 'run' is the command. Cobra requires
 // you to define the usage and description as part of your command
@@ -51,6 +57,9 @@ type Command struct {
 	// Short is the short description shown in the 'help' output.
 	Short string
 
+	// The group under which the command is grouped in the 'help' output.
+	Group string
+
 	// Long is the long message shown in the 'help <this-command>' output.
 	Long string
 
@@ -162,6 +171,9 @@ type Command struct {
 		called bool
 	}
 
+	// groups for commands
+	commandgroups []*Group
+
 	// args is actual args parsed from flags.
 	args []string
 	// flagErrorBuf contains all error messages from pflag.
@@ -194,6 +206,9 @@ type Command struct {
 	// helpCommand is command with usage 'help'. If it's not defined by user,
 	// cobra uses default help command.
 	helpCommand *Command
+	// helpCommandGroup is the default group the helpCommand is in
+	helpCommandGroup string
+
 	// versionTemplate is the version template defined by user.
 	versionTemplate string
 
@@ -263,6 +278,15 @@ func (c *Command) SetHelpCommand(cmd *Command) {
 	c.helpCommand = cmd
 }
 
+// SetHelpCommandGroup sets the group of the help command.
+func (c *Command) SetHelpCommandGroup(group string) {
+	if c.helpCommand != nil {
+		c.helpCommand.Group = group
+	}
+	// helpCommandGroup is used if no helpCommand is defined by the user
+	c.helpCommandGroup = group
+}
+
 // SetHelpTemplate sets help template to be used. Application can use it to set custom template.
 func (c *Command) SetHelpTemplate(s string) {
 	c.helpTemplate = s
@@ -469,10 +493,13 @@ Aliases:
   {{.NameAndAliases}}{{end}}{{if .HasExample}}
 
 Examples:
-{{.Example}}{{end}}{{if .HasAvailableSubCommands}}
+{{.Example}}{{end}}{{if .HasAvailableSubCommands}}{{$cmds := .Commands}}
+
+Available Commands:{{range $cmds}}{{if (and (eq .Group "") (or .IsAvailableCommand (eq .Name "help")))}}
+  {{rpad .Name .NamePadding }} {{.Short}}{{end}}{{end}}{{range $group := .Groups}}
 
-Available Commands:{{range .Commands}}{{if (or .IsAvailableCommand (eq .Name "help"))}}
-  {{rpad .Name .NamePadding }} {{.Short}}{{end}}{{end}}{{end}}{{if .HasAvailableLocalFlags}}
+{{.Title}}{{range $cmds}}{{if (and (eq .Group $group.Group) (or .IsAvailableCommand (eq .Name "help")))}}
+  {{rpad .Name .NamePadding }} {{.Short}}{{end}}{{end}}{{end}}{{end}}{{if .HasAvailableLocalFlags}}
 
 Flags:
 {{.LocalFlags.FlagUsages | trimTrailingWhitespaces}}{{end}}{{if .HasAvailableInheritedFlags}}
@@ -1034,6 +1061,7 @@ Simply type ` + c.Name() + ` help [path to command] for full details.`,
 					cmd.Help()
 				}
 			},
+			Group: c.helpCommandGroup,
 		}
 	}
 	c.RemoveCommand(c.helpCommand)
@@ -1072,6 +1100,10 @@ func (c *Command) AddCommand(cmds ...*Command) {
 			panic("Command can't be a child of itself")
 		}
 		cmds[i].parent = c
+		// if Group is not defined generate a new one with same title
+		if x.Group != "" && !c.ContainsGroup(x.Group) {
+			c.AddGroup(&Group{Group: x.Group, Title: x.Group})
+		}
 		// update max lengths
 		usageLen := len(x.Use)
 		if usageLen > c.commandsMaxUseLen {
@@ -1094,6 +1126,28 @@ func (c *Command) AddCommand(cmds ...*Command) {
 	}
 }
 
+// Groups returns a slice of child command groups.
+func (c *Command) Groups() []*Group {
+	return c.commandgroups
+}
+
+// ContainGroups return if group is in command groups.
+func (c *Command) ContainsGroup(group string) bool {
+	for _, x := range c.commandgroups {
+		if x.Group == group {
+			return true
+		}
+	}
+	return false
+}
+
+// AddGroup adds one or more command groups to this parent command.
+func (c *Command) AddGroup(groups ...*Group) {
+	for _, x := range groups {
+		c.commandgroups = append(c.commandgroups, x)
+	}
+}
+
 // RemoveCommand removes one or more commands from a parent command.
 func (c *Command) RemoveCommand(cmds ...*Command) {
 	commands := []*Command{}