本程序没有使用类，事实上将下面的函数封装到类中可以实现一样的功能。

方便起见，直接在main函数中写好这些程序。



使用了系统自带的list类。



本程序没有进行错误的捕捉与处理，例如在没有open的情况下执行其他命令也没有报错。



执行帮助：

运行文件后输入open打开文件。

输入list，按照提示操作可以查看文件。

输入del，按照提示操作删除某些字符。

输入ins，按照提示操作插入某些字符。

输入quit，保存并退出。-The program does not use the class, in fact, the following function to the class package can achieve the same functionality. Convenience, these programs written directly in the main function. Use the system comes with the list class. The program does not perform error capture and processing, such as executing other commands are not being given in the case of no open. Execution Help: Input open after running the file to open the file. Enter the list, follow the prompts can view the file. Enter del, delete some characters follow the prompts. Enter ins, insert some characters follow the prompts. Enter quit, save and exit.