Question

How can I create an alias for a command in a line-oriented command interpreter implemented using the cmd module?

To create a command, I must implement the do_cmd method. But I have commands with long names (like constraint) and I want to provide aliases (in fact, shortcuts) for these commands (like co). How can I do that?

One possibility that came to my mind is to implement the do_alias (like do_co) method and just calling do_cmd (do_constraint) in this method. But this brings me new commands in the help of the CLI.

Is there any other way to achieve this? Or may be is there a way to hide commands from the help output?

Answer 1

You can overwrite the default method and search for a suitable command handler (as already suggested by Brian):

import cmd

class WithAliasCmd(cmd.Cmd):

    def default(self, line):
        cmd, arg, line = self.parseline(line)
        func = [getattr(self, n) for n in self.get_names() if n.startswith('do_' + cmd)]
        if func: # maybe check if exactly one or more elements, and tell the user
            func[0](arg)