From c105049f7ea5927ec9d7258624391f6a2b43a6a3 Mon Sep 17 00:00:00 2001
From: Victor Vieux <victor@dotcloud.com>
Date: Thu, 11 Apr 2013 16:27:01 +0200
Subject: [PATCH] display usage when no parameter

---
 commands.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/commands.go b/commands.go
index 20d6b45c97..9049596b39 100644
--- a/commands.go
+++ b/commands.go
@@ -389,6 +389,10 @@ func (srv *Server) CmdRm(stdin io.ReadCloser, stdout io.Writer, args ...string)
 	if err := cmd.Parse(args); err != nil {
 		return nil
 	}
+	if cmd.NArg() < 1 {
+		cmd.Usage()
+		return nil
+	}
 	for _, name := range cmd.Args() {
 		container := srv.runtime.Get(name)
 		if container == nil {