Design And Implementation Of A General Command-Line Interface Module

Since the 1980s, graphical user interface (GUI) developed rapidly, and the computer gradually enters all kinds of enterprises, families, and its application is widely promoted. Compared to the command line interface (CLI), graphical interface in the interactivity have incomparable advantages. However, in some need for the implementation of a large number of repetitive work, such as the system management, CLI's scripting, can save users a lot of time. In addition, the CLI requires less system resources than the GUIs. In many embedded devices, the CLI is the only interface. Therefore CLI still has its vitality, is still irreplaceable by the GUIs. The main drawback of CLI is of interactivity, such as the CLI's nothing like the graphic interface to provide help to the user at any time. To enhance the CLI's friendliness, the key is to make the CLI more interactive, to enable users to more easily get access to the most needed help.The objectives of this paper are to improve the friendliness of CLIs, by managing the keywords and parameters of the commands in a unified way, and to provide the users with timely, effective and interactive help messages.Based on the theory of regular expression, this paper presents the command expression to improve the way that we use to describe commands, which make it possible to describe the relationship between parameters and keywords of a command in a flexible way despite central management of commands.This paper focuses on the implementation of a general CLI module, and provides a detailed description of the program flow of it. The module has an open architecture which has the advantages of integrated management as well as the convenient installation of new commands. With the help of command expression and command element type, we are able to validate the user input in the CLI and lower the burden to check command line parameters for a command implementation module, which allows developers to be more concerned with the implementation of commands. In the last two chapters, this paper provides a detailed description of the development of a new command to illustrate the application of the CLI module, summarizes the paper and provides directions of future improvements.