sleep(3C)            COMPATIBILITY FUNCTIONS            sleep(3C)



NAME
     sleep - suspend execution for interval

SYNOPSIS
     #include <unistd.h>

     unsigned sleep (unsigned seconds);

DESCRIPTION
     The current process is  suspended  from  execution  for  the
     number  of  seconds  specified  by the argument.  The actual
     suspension time may be less than that requested because  any
     caught  signal  will terminate the sleep following execution
     of that signal's catching  routine.   Also,  the  suspension
     time  may  be  longer  than requested by an arbitrary amount
     because of the scheduling of other activity in  the  system.
     The  value  returned by sleep will be the ``unslept'' amount
     (the requested time minus the time actually slept)  in  case
     the  caller  had an alarm set to go off earlier than the end
     of the requested sleep time, or premature arousal because of
     another caught signal.

     The routine is implemented by setting an  alarm  signal  and
     pausing  until it (or some other signal) occurs.  The previ-
     ous state of the alarm signal is saved  and  restored.   The
     calling  program may have set up an alarm signal before cal-
     ling sleep.  If the sleep time exceeds the time  until  such
     alarm signal, the process sleeps only until the alarm signal
     would have occurred.  The caller's alarm  catch  routine  is
     executed  just before the sleep routine returns.  But if the
     sleep time is less than the time till such alarm, the  prior
     alarm time is reset to go off at the same time it would have
     without the intervening sleep.

SEE ALSO
     alarm(2), pause(2), signal(2), wait(2).



















          Last change: C Programming Language Utilities         1