Emacs’ universal/prefix argument
I've used C-u
as a prefix to many key presses in emacs and conkeror before. I never really knew what it did. Recently, I read this that show you how to repeat commands by typing M-#
, where #
is a number such as 5 or 100, before a command, such as C-n
or 0
. I've also read function definitions in different .el
files or emacs' documentation that speaks of function arguments. I knew that emacs commands correspond to functions, but I never knew how to pass in arguments.
Basically, C-u #
and M-#
(substitute #
with a number) passes numeric arguments to the function called. C-u
without #
is equivalent to M-4
. Read [[http://www.gnu.org/software/emacs/manual/html_ node/emacs/Arguments.html][this]] for a more thorough explanation. This shows how one can "overload" a function using the prefix argument.