Re: How to detect C-u supplied arguments from other prefix arguments

[dieter . wilhelm]

On 8 août, 07:06, Kevin Rodgers <kevin.d.rodg...@gmail.com> wrote:
> Dieter Wilhelm wrote:
> > I'd like to detect whether prefix arguments of a command are supplied
> > by C-u or otherwise.
> > My idea is to use this-command-keys and compare it to some string,
> > like the following pseudo code:
>
> > (defun bla (arg)
> >   (interactive "p")
> >   (when (string= "C-u" (substring (this-command-keys) 0 2))
> >     (message "hurray")))
>
> > I just don't understand how to compare key sequences.  Or maybe
> > there's better way of doing it?
>
> Yuck.  If all you're concerned about is whether the prefix arg was
> specified by 1 or more C-u keys (with no minus sign or digits), you
> can use (consp current-prefix-arg).

Unfortunately this doesn't work in all cases:  I'd also like to
specify numerical
arguments with C-u (not only powers of 4).   For example

C-u 3 M-x some-command

and would like to distinguish it from other means of supplying
numerical
arguments e.g.:

M-3 M-x some-command

> Kevin Rodgers
Thanks
  Dieter