Add command arguments to help menu and don't show available options if there aren't any

help.go

@@ -21,8 +21,17 @@ func (c *Command) ShowHelp() {
 			fmt.Print("<command> ")
 		}
 	}
-
-	fmt.Println("[options]")
+	fmt.Print("[options]")
+	if len(c.arguments) > 0 {
+		for _, a := range c.arguments {
+			if a.Required {
+				fmt.Print(" <" + a.Name + ">")
+			} else {
+				fmt.Print(" [" + a.Name + "]")
+			}
+		}
+	}
+	fmt.Println()
 
 	if len(c.subcommands) > 0 {
 		fmt.Println()
@@ -38,19 +47,20 @@ func (c *Command) ShowHelp() {
 		}
 	}
 
+	if len(c.opts) > 0 {
 		fmt.Println()
 		fmt.Println("Available options:")
-
 		paddedWidth := c.opts.MaxWidth()
 		for _, f := range c.opts {
 			fmt.Println("  " + opt.HelpLine(f, paddedWidth))
 		}
+	}
 
 	globalOpts := opt.Globals()
 	if len(globalOpts) > 0 {
-		paddedWidth = globalOpts.MaxWidth()
 		fmt.Println()
 		fmt.Println("Global options:")
+		paddedWidth := globalOpts.MaxWidth()
 		for _, f := range globalOpts {
 			fmt.Println("  " + opt.HelpLine(f, paddedWidth))
 		}