these hooks, it terminates execution of the hook, and clears the hook
variable to @code{nil} so as to prevent an infinite loop of errors.
+ A request coming into the Emacs server (@pxref{Emacs Server,,,
+emacs, The GNU Emacs Manual}) runs these two hooks just as a keyboard
+command does.
+
@node Defining Commands
@section Defining Commands
@cindex defining commands
input comes in, while @code{sleep-for} pauses without updating the
screen.
-@defun sit-for seconds &optional millisec nodisp
+@defun sit-for seconds &optional nodisp
This function performs redisplay (provided there is no pending input
from the user), then waits @var{seconds} seconds, or until input is
available. The value is @code{t} if @code{sit-for} waited the full
Some systems support only a whole number of seconds; on these systems,
@var{seconds} is rounded down.
-The optional argument @var{millisec} specifies an additional waiting
-period measured in milliseconds. This adds to the period specified by
-@var{seconds}. If the system doesn't support waiting fractions of a
-second, you get an error if you specify nonzero @var{millisec}.
-
The expression @code{(sit-for 0)} is a convenient way to request a
redisplay, without any delay. @xref{Forcing Redisplay}.
The usual purpose of @code{sit-for} is to give the user time to read
text that you display.
+
+It is also possible to call @code{sit-for} with three arguments,
+as @code{(sit-for @var{seconds} @var{millisec} @var{nodisp})},
+but that is considered obsolete.
@end defun
@defun sleep-for seconds &optional millisec