diff --git a/src/cli/command_parser.rb b/src/cli/command_parser.rb
index 357d1082ab..5165a668b3 100755
--- a/src/cli/command_parser.rb
+++ b/src/cli/command_parser.rb
@@ -338,7 +338,11 @@ EOT
                         }.join(' ')
 
                         puts "Wrong number of arguments"
-                        puts "The arguments should be: #{args_str}"
+                        if args_str.empty?
+                            puts "No argument is required"
+                        else
+                            puts "The arguments should be: #{args_str}"
+                        end
                         exit -1
                     end
 
@@ -346,7 +350,15 @@ EOT
                     argument = nil
                     error_msg = nil
                     format.each { |f|
-                        format_hash = @formats[f] ? @formats[f] : @formats[:text]
+                        if @formats[f]
+                            format_hash = @formats[f]
+                        elsif f.nil?
+                            argument = nil
+                            break
+                        else
+                            format_hash = @formats[:text]
+                        end
+
                         rc = format_hash[:proc].call(arg)
                         if rc[0]==0
                             argument=rc[1]