python - 检查通过 python cmd 模块传递的参数

Question

这是一个两部分的问题，请看下面:

• 我需要创建某种控制台供测试人员用来手动运行某些命令! 是cmd模块好走吗？

下面是我目前使用 cmd 的代码模块，我只是想学习，到目前为止我有两个问题:

• 为什么自动完成功能不起作用？如果我加倍 <TAB>我什么也没得到，光标只是向前移动。不是默认提供了自动完成功能吗？

• 我是否必须为每个方法处理错误数量的参数？如果使用错误数量的参数调用方法，或者在应该使用参数调用但实际上没有调用方法时，我希望方法 - “帮助”文本自动显示。

.

class InteractiveConsole(cmd.Cmd):
    """ Interactive command line """

    def __init__(self):
        cmd.Cmd.__init__(self)
        self.prompt = "=>> "
        self.intro = "Welcome to IRT console!"

    def do_hist(self, args):
        """Print a list of commands that have been entered"""
        print self._hist

    def do_exit(self, args):
        """Exits from the console"""
        return -1

    def do_help(self, args):
        """Get help on commands
           'help' or '?' with no arguments prints a list of commands for which help is available
           'help <command>' or '? <command>' gives help on <command>
        """
        # # The only reason to define this method is for the help text in the doc string
        cmd.Cmd.do_help(self, args)

    # # Override methods in Cmd object ##
    def preloop(self):
        """Initialization before prompting user for commands.
           Despite the claims in the Cmd documentaion, Cmd.preloop() is not a stub.
        """
        cmd.Cmd.preloop(self)  # # sets up command completion
        self._hist = []  # # No history yet
        self._locals = {}  # # Initialize execution namespace for user
        self._globals = {}

    def postloop(self):
        """Take care of any unfinished business.
           Despite the claims in the Cmd documentaion, Cmd.postloop() is not a stub.
        """
        cmd.Cmd.postloop(self)  # # Clean up command completion
        print "Exiting..."

    def precmd(self, line):
        """ This method is called after the line has been input but before
            it has been interpreted. If you want to modify the input line
            before execution (for example, variable substitution) do it here.
        """
        if line != '':
            self._hist += [ line.strip() ]
        return line

    def postcmd(self, stop, line):
        """If you want to stop the console, return something that evaluates to true.
           If you want to do some post command processing, do it here.
        """
        return stop

    def default(self, line):
        """Called on an input line when the command prefix is not recognized.
           In that case we execute the line as Python code.
        """
        try:
            exec(line) in self._locals, self._globals
        except Exception, e:
            print e.__class__, ":", e

    def emptyline(self):
        """Do nothing on empty input line"""
        pass





    def do_install(self, pathToBuild):
        """install [pathToBuild]
        install using the specified file"""
        if pathToBuild:
            print "installing %s" % pathToBuild
        else:
            print "<ERROR> You must specify the absolute path to a file which should be used!"


    def do_configure(self, pathToConfiguration):
        """configure [pathToConfiguration]
        configure using the specified file"""
        if pathToConfiguration:
            print "configuring %s" % pathToConfiguration
        else:
            print "<ERROR> You must specify the absolute path to a file which should be used!"

Answer 1

来自 cmd documentation :

The optional argument completekey is the readline name of a completion key; it defaults to Tab. If completekey is not None and readline is available, command completion is done automatically.

你需要有 readline可用于制表符完成工作。

命令方法只接受一个 参数，您需要在命令方法本身中解析参数。您当然可以调用self.do_help()或 self.help_<cmd>()必要时的方法。