add ArgsUsage to App and Command

app.go

@@ -15,6 +15,8 @@ type App struct {
 	Name string
 	// Description of the program.
 	Usage string
+	// Description of the program argument format.
+	ArgsUsage string
 	// Version of the program
 	Version string
 	// List of commands to execute
@@ -68,6 +70,7 @@ func NewApp() *App {
 	return &App{
 		Name:         os.Args[0],
 		Usage:        "A new cli application",
+		ArgsUsage:    "[arguments...]",
 		Version:      "0.0.0",
 		BashComplete: DefaultAppComplete,
 		Action:       helpCommand.Action,

command.go

@@ -18,6 +18,8 @@ type Command struct {
 	Usage string
 	// A longer explanation of how the command works
 	Description string
+	// A short description of the arguments of this command
+	ArgsUsage string
 	// The function to call when checking for bash command completions
 	BashComplete func(context *Context)
 	// An action to execute before any sub-subcommands are run, but after the context is ready
@@ -158,6 +160,9 @@ func (c Command) startApp(ctx *Context) error {
 	} else {
 		app.Usage = c.Usage
 	}
+	if c.ArgsUsage == "" {
+		c.ArgsUsage = "[arguments...]"
+	}
 
 	// set CommandNotFound
 	app.CommandNotFound = ctx.App.CommandNotFound

help.go

@@ -15,7 +15,7 @@ var AppHelpTemplate = `NAME:
    {{.Name}} - {{.Usage}}
 
 USAGE:
-   {{.Name}} {{if .Flags}}[global options]{{end}}{{if .Commands}} command [command options]{{end}} [arguments...]
+   {{.Name}} {{if .Flags}}[global options]{{end}}{{if .Commands}} command [command options]{{end}} {{.ArgsUsage}}
    {{if .Version}}
 VERSION:
    {{.Version}}
@@ -41,7 +41,7 @@ var CommandHelpTemplate = `NAME:
    {{.FullName}} - {{.Usage}}
 
 USAGE:
-   command {{.FullName}}{{if .Flags}} [command options]{{end}} [arguments...]{{if .Description}}
+   command {{.FullName}}{{if .Flags}} [command options]{{end}} {{.ArgsUsage}}{{if .Description}}
 
 DESCRIPTION:
    {{.Description}}{{end}}{{if .Flags}}
@@ -58,7 +58,7 @@ var SubcommandHelpTemplate = `NAME:
    {{.Name}} - {{.Usage}}
 
 USAGE:
-   {{.Name}} command{{if .Flags}} [command options]{{end}} [arguments...]
+   {{.Name}} command{{if .Flags}} [command options]{{end}} {{.ArgsUsage}}
 
 COMMANDS:
    {{range .Commands}}{{join .Names ", "}}{{ "\t" }}{{.Usage}}
@@ -72,6 +72,7 @@ var helpCommand = Command{
 	Name:      "help",
 	Aliases:   []string{"h"},
 	Usage:     "Shows a list of commands or help for one command",
+	ArgsUsage: "[command]",
 	Action: func(c *Context) {
 		args := c.Args()
 		if args.Present() {
@@ -86,6 +87,7 @@ var helpSubcommand = Command{
 	Name:      "help",
 	Aliases:   []string{"h"},
 	Usage:     "Shows a list of commands or help for one command",
+	ArgsUsage: "[command]",
 	Action: func(c *Context) {
 		args := c.Args()
 		if args.Present() {