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% File src/library/base/man/Sys.sleep.Rd
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% File src/library/base/man/Sys.sleep.Rd
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% Part of the R package, https://www.R-project.org
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% Part of the R package, https://www.R-project.org
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% Copyright 1995-2007 R Core Team
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% Copyright 1995-2015 R Core Team
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% Distributed under GPL 2 or later
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% Distributed under GPL 2 or later
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\name{Sys.sleep}
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\name{Sys.sleep}
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\alias{Sys.sleep}
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\alias{Sys.sleep}
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\title{Suspend Execution for a Time Interval}
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\title{Suspend Execution for a Time Interval}
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\description{
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\description{
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  Suspend execution of \R expressions for a given number of seconds
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  Suspend execution of \R expressions for a specified time interval.
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}
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}
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\usage{
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\usage{
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Sys.sleep(time)
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Sys.sleep(time)
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}
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}
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\arguments{
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\arguments{
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  \item{time}{The time interval to suspend execution for, in seconds.}
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  \item{time}{The time interval to suspend execution for, in seconds.}
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}
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}
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\details{
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\details{
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  Using this function allows \R to be given very low priority and hence
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  Using this function allows \R to temporarily be given very low
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  not to interfere with more important foreground tasks.  A typical use
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  priority and hence not to interfere with more important foreground
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  is to allow a process launched from \R to set itself up and read its
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  tasks.  A typical use is to allow a process launched from \R to set
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  input files before \R execution is resumed.
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  itself up and read its input files before \R execution is resumed.
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  The intention is that this function suspends execution of \R
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  The intention is that this function suspends execution of \R
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  expressions but wakes the process up often enough to respond to GUI
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  expressions but wakes the process up often enough to respond to GUI
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  events, typically every 0.5 seconds.
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  events, typically every half second.  It can be interrupted
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  (e.g.\sspace{}by \samp{Ctrl-C} or \samp{Esc} at the \R console).
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  There is no guarantee that the process will sleep for the whole of the
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  There is no guarantee that the process will sleep for the whole of the
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  specified interval, and it may well take slightly longer in real time
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  specified interval (sleep might be interrupted), and it may well take
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  slightly longer in real time to resume execution.
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  \code{time} must be non-negative (and not \code{NA} nor \code{NaN}):
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  \code{Inf} is allowed (and might be appropriate if the intention is to
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  to resume execution.  The resolution of the time interval is
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  wait indefinitely for an interrupt).  The resolution of the time
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  system-dependent, but will normally be down to 0.02 secs or better.
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  interval is system-dependent, but will normally be 20ms or better.
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  (On modern Unix-alikes it will be better than 1ms.)
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  (On modern Unix-alikes it will be better than 1ms.)
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}
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}
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\value{
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\value{
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  Invisible \code{NULL}.
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  Invisible \code{NULL}.
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}
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}
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\note{
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\note{
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  This function may not be implemented on all systems.  Where it is not
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  Despite its name, this is not currently implemented using the
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  implemented calling it given an error.
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  \code{sleep} system call (although on Windows it does make use of
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  \code{Sleep}).
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}
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}
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\examples{\donttest{
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\examples{\donttest{
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testit <- function(x)
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testit <- function(x)
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{
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{