diff --git a/database/commandinfo.go b/database/commandinfo.go
index 020e4bb..afe283c 100644
--- a/database/commandinfo.go
+++ b/database/commandinfo.go
@@ -24,24 +24,22 @@ const (
 )
 
 func execCommand(args [][]byte) redis.Reply {
-	n := len(args)
-	if n > 1 {
-		subCommand := strings.ToLower(string(args[1]))
-		if subCommand == "info" {
-			return getCommands(args[2:])
-		} else if subCommand == "count" {
-			return protocol.MakeIntReply(int64(len(cmdTable)))
-		} else if subCommand == "getkeys" {
-			if n < 2 {
-				return protocol.MakeErrReply("Unknown subcommand or wrong number of arguments for '" + subCommand + "'")
-			}
-			return getKeys(args[2:])
-		} else {
-			return protocol.MakeErrReply("Unknown subcommand or wrong number of arguments for '" + subCommand + "'")
-		}
-	} else {
+	if len(args) == 0 {
 		return getAllGodisCommandReply()
 	}
+	subCommand := strings.ToLower(string(args[0]))
+	if subCommand == "info" {
+		return getCommands(args[1:])
+	} else if subCommand == "count" {
+		return protocol.MakeIntReply(int64(len(cmdTable)))
+	} else if subCommand == "getkeys" {
+		if len(args) < 2 {
+			return protocol.MakeErrReply("wrong number of arguments for 'command|" + subCommand + "'")
+		}
+		return getKeys(args[1:])
+	} else {
+		return protocol.MakeErrReply("Unknown subcommand '" + subCommand + "'")
+	}
 }
 
 func getKeys(args [][]byte) redis.Reply {
diff --git a/database/commandinfo_test.go b/database/commandinfo_test.go
index 26ba0da..3575950 100644
--- a/database/commandinfo_test.go
+++ b/database/commandinfo_test.go
@@ -16,5 +16,5 @@ func TestCommandInfo(t *testing.T) {
 	ret = testServer.Exec(c, utils.ToCmdLine("command", "getkeys", "mset", "a", "a", "b", "b"))
 	asserts.AssertMultiBulkReply(t, ret, []string{"a", "b"})
 	ret = testServer.Exec(c, utils.ToCmdLine("command", "foobar"))
-	asserts.AssertErrReply(t, ret, "Unknown subcommand or wrong number of arguments for 'foobar'")
+	asserts.AssertErrReply(t, ret, "Unknown subcommand 'foobar'")
 }
diff --git a/database/server.go b/database/server.go
index 52c565c..f93a9d9 100644
--- a/database/server.go
+++ b/database/server.go
@@ -122,7 +122,7 @@ func (server *Server) Exec(c redis.Connection, cmdLine [][]byte) (result redis.R
 		}
 		return server.execSlaveOf(c, cmdLine[1:])
 	} else if cmdName == "command" {
-		return execCommand(cmdLine)
+		return execCommand(cmdLine[1:])
 	}
 
 	// read only slave