Merge pull request #104 from marco-m/subcommands-usage-simple

Subcommands usage simple

example_test.go

@@ -193,7 +193,7 @@ func Example_helpTextWithSubcommand() {
 	MustParse(&args)
 
 	// output:
-	// Usage: example [--verbose]
+	// Usage: example [--verbose] <command> [<args>]
 	//
 	// Options:
 	//   --verbose

parse.go

@@ -129,7 +129,7 @@ type Parser struct {
 	version     string
 	description string
 
-	// the following fields change curing processing of command line arguments
+	// the following field changes during processing of command line arguments
 	lastCmd *command
 }
 

usage.go

@@ -88,6 +88,12 @@ func (p *Parser) writeUsageForCommand(w io.Writer, cmd *command) {
 			fmt.Fprint(w, spec.placeholder)
 		}
 	}
+
+	// if the program supports subcommands, give a hint to the user about their existence
+	if len(cmd.subcommands) > 0 {
+		fmt.Fprint(w, " <command> [<args>]")
+	}
+
 	fmt.Fprint(w, "\n")
 }