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

[Kevin Rodgers]

Dieter Wilhelm wrote:
> Hi
>
> 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).

--
Kevin Rodgers
Denver, Colorado, USA