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SLEEP(3)                 BSD Library Functions Manual                 SLEEP(3)

     sleep -- suspend thread execution for an interval measured in seconds

     Standard C Library (libc, -lc)

     #include <unistd.h>

     unsigned int
     sleep(unsigned int seconds);

     The sleep() function suspends execution of the calling thread until
     either seconds seconds have elapsed or a signal is delivered to the
     thread and its action is to invoke a signal-catching function or to ter-minate terminate
     minate the thread or process.  System activity may lengthen the sleep by
     an indeterminate amount.

     This function is implemented using nanosleep(2) by pausing for seconds
     seconds or until a signal occurs.  Consequently, in this implementation,
     sleeping has no effect on the state of process timers, and there is no
     special handling for SIGALRM.

     If the sleep() function returns because the requested time has elapsed,
     the value returned will be zero.  If the sleep() function returns due to
     the delivery of a signal, the value returned will be the unslept amount
     (the requested time minus the time actually slept) in seconds.

     nanosleep(2), usleep(3)

     The sleep() function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'').

     A sleep() function appeared in Version 7 AT&T UNIX.

BSD                            February 13, 1998                           BSD