cmd: Note commands which need obscured input in the docs - fixes #4252

cmd/cmd.go

@@ -486,6 +486,9 @@ func AddBackendFlags() {
 					help = help[:nl]
 				}
 				help = strings.TrimSpace(help)
+				if opt.IsPassword {
+					help += " (obscured)"
+				}
 				flag := pflag.CommandLine.VarPF(opt, name, opt.ShortOpt, help)
 				if _, isBool := opt.Default.(bool); isBool {
 					flag.NoOptDefVal = "true"

cmd/help.go

@@ -325,6 +325,9 @@ func showBackend(name string) {
 			}
 			fmt.Printf("#### --%s%s\n\n", opt.FlagName(backend.Prefix), shortOpt)
 			fmt.Printf("%s\n\n", opt.Help)
+			if opt.IsPassword {
+				fmt.Printf("**NB** Input to this must be obscured - see [rclone obscure](/commands/rclone_obscure/).\n\n")
+			}
 			fmt.Printf("- Config:      %s\n", opt.Name)
 			fmt.Printf("- Env Var:     %s\n", opt.EnvVarName(backend.Prefix))
 			fmt.Printf("- Type:        %s\n", opt.Type())