gistfile1.txt

from cmd import Cmd

class MyCmd(Cmd):
    def onecmd(self, str):
        if str == 'ls':
            # here we should print the files in the cwd
            print 'No files. Sorry!'


    def precmd(self, line):
        print 'the user entered %s' % line
        return 'dir'

    def postcmd(self, stop, line):
        print 'This will be dir, since we are returning that on precmd ', line
        if stop:
            return 'stopthis'
        return line
    

c = MyCmd()
c.cmdloop()