Ignore/pass over the double dash (--) marker

[Higgcz]

I'm working on a command line application which includes something like ssh wrapper. Basically what I'm doing is I'm resolving hostname myself, but then I want to pass all other parameters to the underlying ssh command. However, I've noticed that Click is consuming the first double dash (--) marker.

I was hoping Click has somewhere a variable containing all unprocessed arguments, but apparently, that's not the case, or at least I couldn't find it. So, in the end, I ended up adding one more click.Context option called ignore_end_of_the_opts_marker that tells Click to pass over the double dash, so if you combine it with ignore_unknown_options, you can pick all unprocessed arguments.

Eg.:

@click.command(context_settings=dict(
    ignore_unknown_options=True,
    ignore_end_of_the_opts_marker=True
    ))
@click.argument('args', nargs=-1, type=click.UNPROCESSED)
@click.pass_context
def cli(ctx, args):
    print('All the arguments:', args)

I've noticed some people are also writing wrapper-like tools, so maybe more people would be interested in this option.

So far, I'm not sure if it's worth a Pull Request, let me know if it is, I've tried to document everything consistently with the rest of the code, but I can imagine there could be a better name for this option. Or maybe you have a better idea of how to solve this issue.

Anyway, if someone is interested, here is my fork: https://github.com/Higgcz/click

[adzenith]

Thoughts on making this into a PR? I would love to see this in upstream click.

[Midnighter]

I was looking for this possibility right now as it is becoming a common CLI pattern. Thank you for providing the code.

[sashati]

Apparently, the Fork is kind of outdated. If anybody knows a way to resolve this issue?

[POD666]

I end up with the following snippet:

class HandleDoubleDashArg(click.Group):
    def parse_args(self, ctx, args):
        if "--" in args:
            # concat all options that follow double dash into tuple
            double_dash_idx = args.index("--")
            args = args[:double_dash_idx] + [tuple(args[double_dash_idx + 1 :])]
            # ['--arg', '123', '--', 'qwe', 'rty'] -> ['--arg', '123', ('qwe', 'rty')]
        elif "--help" in args:
            pass  # skip if help is requested
        else:
            # trick: feed an empty string as positional argument
            # so that the latests from args is considered as child command

            # find child command
            for child_command in self.commands:
                if child_command in args:
                    idx = args.index(child_command)
                    args.insert(idx, ())
                    # ['--arg', '123', 'my_child_command'] -> ['--arg', '123', (), 'my_child_command']
                    break
            else:
                # TODO: to be improved
                args.insert(-1, ())
                # ['--arg', '123', 'qwerty'] -> ['--arg', '123', (), 'qwerty']
                # -> should lead to `Error: No such command 'qwerty'`
                # ['--arg', '123', 'qwerty', '--qwe'] -> ['--arg', '123', 'qwerty', (), '--qwe']
                # -> Error: No such command '()'.
                # ['--arg', '123', 'qwerty', '--qwe', '--rty'] -> ['--arg', '123', 'qwerty', '--qwe', (), '--rty']
                # -> Error: No such command '--qwe'.
        super(HandleDoubleDashArg, self).parse_args(ctx, args)


@click.group(cls=HandleDoubleDashArg, invoke_without_command=True)
@click.option("--arg")
@click.argument("double_dash_args")
@click.pass_context
def my_group_command(ctx, double_dash_args):
    # ...
    if ctx.invoked_subcommand is None:
        # ...
        pass


@my_group_command.command()
def my_child_command(ctx):
    # ...
    pass

It's limited to my use case but might be helpful.

[davidism]

Pretty much a duplicate of #619, see additional discussion there. Just like if you need to pass an argument that looks like an option, use -- if you need to pass a -- as an argument.

wrapper -- ssh -v -- bash -c ...