Richard,

In general, whenever apropos identifies a routine as a "Command" that 
means you can execute it from the minibuffer using M-x

When apropos identifies a routine as a "Function," M-x does not work; 
but you can still execute it from the minibuffer as a typed-in lisp 
function call using M-:

For example, you could set register 'a' to the string "hello" by typing
M-:
Eval: (set-register ?a "hello")

You could make your own interactive M-x command called set-reg-string 
to prompt you in the minibuffer for a register name and a string to 
be stored in that register by adding this to your .emacs file:

   (defun set-reg-string (reg string)
     (interactive "cRegister: \nsString: ")
     (set-register reg string))

If you try this, you will find that as soon as you type a character 
in response to the "Register: " prompt it advances immediately to the 
"String: " prompt without giving you a chance to see or edit the 
register name.  You could fix this by changing your command 
definition to:

   (defun set-reg-string (reg string)
     (interactive "sRegister: \nsString: ")
     (set-register (elt reg 0) string))

To learn more about creating your own interactive commands, consult 
the "Command Loop" chapter in the GNU Emacs Lisp Reference Manual, 
available for download in many formats at:

http://www.sunsite.ualberta.ca/Documentation/Gnu/emacs-lisp-ref-21-2.7/emacs-lisp-ref.html

--Greg


At 5:57 PM +0100 9/12/02, lawrence mitchell wrote:
>Richard White wrote:
>
>>  I'm trying to make use of the registers in GNU Emacs but when I run
>>  the command set-register the minibuffer says there is no match
>>  (Despite apropos listing it).  I'm using version 20.2.1; does this
>>  version have register use enabled and if so how do I get it to work
>>  (please)?
>
>set-register isn't an interactive function, i.e. you can't call
>it via M-x or through a keybinding.  The Emacs manual describes
>how to use registers in far more detail than I ever could, see
>the Info node "(emacs)Registers", you can get there by evaluating
>(Info-goto-node "(emacs)Registers") in Emacs.
>
>--
>lawrence mitchell <wence@gmx.li>