Python's cmd library learning

One: cmd introduction

official documents that refer to Python

The cmd class provides a simple framework for writing Line-orientedcommand interpreters. These is often useful for test harnesses, administrativetools, and prototypes that'll later be wrapped in a more sophis Ticatedinterface

CMD is a simple framework for writing programs based on a command-line interpreter, which is often useful for testing tools, management tools, and prototypes later wrapped in more complex interfaces.

II: basic use of CMD

There are several points to note when writing a CMD-based program:

1. to inherit from CMD. CMD Class 2. To initialize the parent Class 3. All commands are preceded by Do_ 4. All command Help is preceded by Help_ 5. A command corresponds to a help, and an error occurs if no help is executed.

Three: cmd example

     

# -*- coding: utf-8 -*- #!/usr/bin/python env# introduces some package import sysimport  cmdimport os# inherits the CMD. CMD class class cli (cmd). CMD):         def __init__ (self):                  #先初始化父类                  cmd.cmd.__init__ (self)                   #设置命令行的提示符                  self.prompt =  "<zhang> "     #第一个命令dir命令 with one parameter              def do_dir (Self,arg):                 if not arg:        &nBsp;               self.help_dir ()                 elif  Os.path.exists (ARG):                         print  "\ n". Join (Os.listdir (ARG))                  else:                          print  "no such pathexists"      #带第二个命令          def do_quit (Self,arg):                 return True     #dir命令的帮助          d Ef help_dir (self):                 print  "syntax:dir path -- displaya list of files and  Directories "     #help命令的帮助         def help_ Quit (self):                 print  "Syntax:quit --terminatesthe application"      #命令的别名          do_q = do_quitif __name__ ==  "__main__": #开始执行cmd   &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;CLI&NBSP;=&NBSP;CLI () #循环接受用户输入的命令          cli.cmdloop ()

IV: Implementation Results

[[email protected] python]# python cmdtest.py <zhang>dirsyntax:dir path--Displaya list of files and directories< ; Zhang>dir/ Tmpkeyring-8mjwb8ferret.ice-unixkeyring-6y9txtorbit-gdm.x11-unixkeyring-e2wqqa.x0-lockpulse-weknqpdx0htqkeyring-aoiv8ekey ring-i47izekeyring-bshjbupulse-8tdhlwhpdc2jkeyring-viwkfekeyring-m5pgn7keyring-pb8q2xkeyring-tme3bwkeyring-gtw1ih.esd-0  <zhang>helpdocumented commands (Type help <topic>): ========================================dir quitundocumented Commands:======================help Q<zhang>q

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