SLEEP(3C)           UNIX Programmer's Manual            SLEEP(3C)

NAME
     sleep - suspend execution for interval

SYNOPSIS
     unsigned long sleep (seconds)
     unsigned long seconds;

HP-UX COMPATIBILITY
     Level:    HP-UX/RUN ONLY

     Origin:   System III

DESCRIPTION
     The current process is  suspended  from  execution  for  the
     number  of  _s_e_c_o_n_d_s  specified  by the argument.  The actual
     suspension time may be less than that requested for two rea-
     sons:  (1) Because scheduled wakeups occur at fixed 1-second
     intervals, and (2) because any caught signal will  terminate
     the _s_l_e_e_p following execution of that signal's catching rou-
     tine.   Also,  the  suspension  time  may  be  longer   than
     requested  by  an  arbitrary amount due to the scheduling of
     other activity in the system.  The value returned  by  _s_l_e_e_p
     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 _s_l_e_e_p time, or
     premature arousal due to 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 _s_l_e_e_p.  If the _s_l_e_e_p time exceeds the time till such an
     alarm signal, the process sleeps only until the alarm signal
     would have occurred, and the caller's alarm catching routine
     is  executed  just before the _s_l_e_e_p routine returns.  If the
     _s_l_e_e_p time is less than the time till  such  an  alarm,  the
     prior  alarm  time  is  reset  to go off at the same time it
     would have without the intervening _s_l_e_e_p.

     _S_e_c_o_n_d_s must be less than 2^32.

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