add option -f to usage and filter support (#64)

cmd/root.go

@@ -248,9 +248,11 @@ func Debug(conf *cfg.Config) *cli.Command {
 
 func HelpUsage(conf *cfg.Config) *cli.Command {
 	return &cli.Command{
-		Name:    "help-command-overview",
-		Usage:   "show overview of all available commands",
-		Aliases: []string{"usage"},
+		Name:               "help-usage",
+		Usage:              "show overview of all available commands",
+		UsageText:          "help-usage [<filter>]",
+		Aliases:            []string{"usage"},
+		CustomHelpTemplate: addReference(`<filter> implies -f`),
 
 		Flags: []cli.Flag{
 			&cli.BoolFlag{
@@ -259,16 +261,32 @@ func HelpUsage(conf *cfg.Config) *cli.Command {
 				Destination: &conf.Hidden,
 				Aliases:     []string{"H"},
 			},
+			&cli.BoolFlag{
+				Name:        "full-commands",
+				Usage:       "show full commands",
+				Destination: &conf.Force,
+				Aliases:     []string{"f"},
+			},
 		},
 
 		Action: func(ctx context.Context, cmd *cli.Command) error {
 			maxCommandWidth := 0
+			filter := cmd.Args().Get(0)
+
+			if filter != "" {
+				conf.Force = true
+			}
 
 			// first pass, determine max command width
 			if err := walkVisible(conf, cmd.Root(), func(cmd *cli.Command) error {
 				path := cmd.Path()
 				size := len(path[len(path)-1])
 
+				if conf.Force {
+					path := strings.Join(cmd.Path(), " ")
+					size = len(path)
+				}
+
 				if size > maxCommandWidth {
 					maxCommandWidth = size
 				}
@@ -283,9 +301,19 @@ func HelpUsage(conf *cfg.Config) *cli.Command {
 			// second pass, build tree
 			return walkVisible(conf, cmd.Root(), func(cmd *cli.Command) error {
 				path := cmd.Path()
-				command := path[len(path)-1]
 
-				if len(path) == 1 || command == "help" {
+				if filter != "" {
+					if !strings.Contains(strings.Join(path, " "), filter) {
+						return nil
+					}
+				}
+
+				command := path[len(path)-1]
+				if conf.Force {
+					command = strings.Join(cmd.Path(), " ")
+				}
+
+				if len(path) == 1 || strings.HasSuffix(command, "help") {
 					return nil
 				}