             result = try self.execute(command!)
         } catch {
             DDLogWarn("command execute error.")
-            self.delegate?.didReturnResult("command execute error.")
+            self.delegate?.didReturnResult("command execute error:\(error)")
             return false
         }
         

            command = try CommandLineParser.shareParser.buildCommand(commandLine!)
        } catch {
            DDLogWarn("command build error.")
            self.delegate?.didReturnResult("command build error.")
            return false
        }
        

            commandLine = try CommandLineParser.shareParser.parse(string)
        } catch {
            DDLogWarn("command parse error.")
            self.delegate?.didReturnResult("command parse error:\(error)")
            return false
        }
        
