How to use describe-key with multi-key sequences?

How to use describe-key with multi-key sequences?

[bill]

How can one describe-key with "compound commands" such as "C-u f" in
mail-mode?  If I try C-h k C-u f, I get the description of C-u, not
the description of C-u f...

Thanks in advance!

bill

Re: How to use describe-key with multi-key sequences?

[Michael Slass]

bill <bill_knight2@yahoo.com> writes:

>How can one describe-key with "compound commands" such as "C-u f" in
>mail-mode?  If I try C-h k C-u f, I get the description of C-u, not
>the description of C-u f...
>
>Thanks in advance!
>
>bill
>

C-u runs universal-prefix-arg.  What you want to do is to get the
description of the function run by the key "f", and read that to see
how the behavior is modified by a prefix arg.  For example to see what
happens with C-u M-; ...   

C-h k M-;

,----
| M-; runs the command comment-dwim
|    which is an interactive compiled Lisp function in `newcomment'.
| (comment-dwim ARG)
| 
| Call the comment command you want (Do What I Mean).
| If the region is active and `transient-mark-mode' is on, call
|   `comment-region' (unless it only consists of comments, in which
|   case it calls `uncomment-region').
| Else, if the current line is empty, insert a comment and indent it.
| Else if a prefix ARG is specified, call `comment-kill'.
| Else, call `comment-indent'.
`----

This tells me that M-; runs comment-dwim (do what i mean).  The second
line up from the bottom says that with a prefix arg (meaning that I
hit C-u first), it will run comment-kill instead.

-- 
Mike Slass