os.sleep

Function os.sleep
Pauses the computer for a number of seconds. Fractions of a second are supported, but only down to a game tick, or 1/20 of a second (0.05s). Times are rounded up to the next tick, so os.sleep(1.01) and os.sleep(1.05) both wait for 1.05 seconds. You can also use sleep( timeout ).
Syntax	os.sleep(number timeout)
Returns	nil
Part of	ComputerCraft
API	OS

Examples

Example
Pause for 3 seconds.
Code	os.sleep( 3 )

Concerns when using events

The implementation of the sleep function is as follows:

function sleep( _nTime )
  local timer = os.startTimer( _nTime )
  
  repeat
    local sEvent, param = os.pullEvent( "timer" )
  until param == timer
end

If you are using events and the sleep function at the same time, you may notice events received during the sleep never firing. The sleep function continually loops, emptying the event queue, until the timer event fires. If you still want to sleep, you should create your own sleep function which takes care of the events while sleeping. One such function would be:

-- Replacement for sleep, which passes on events instead of dropping them

local function wait ( time )
  local timer = os.startTimer(time)
  
  while true do
    local event = {os.pullEvent()}
    
    if (event[1] == "timer" and event[2] == timer) then
      break
    else
      processEvents(event) -- a custom function in which you would deal with received events
    end
  end
end