usleep(3) [mojave man page]

USLEEP(3)						   BSD Library Functions Manual 						 USLEEP(3)

NAME

     usleep -- suspend thread execution for an interval measured in microseconds

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <unistd.h>

     int
     usleep(useconds_t microseconds);

DESCRIPTION

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

     This function is implemented using nanosleep(2) by pausing for microseconds microseconds 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.  Also, this implementa-
     tion does not put a limit on the value of microseconds (other than that limited by the size of the useconds_t type); some other platforms
     require it to be less than one million.

NOTE

     The usleep() function is obsolescent.  Use nanosleep(2) instead.

RETURN VALUES

     The usleep() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate
     the error.

ERRORS

     The usleep() function will fail if:

     [EINTR]		A signal was delivered to the process and its action was to invoke a signal-catching function.

SEE ALSO

     nanosleep(2), sleep(3)

HISTORY

     The usleep() function appeared in 4.3BSD.

BSD
								 February 13, 1998							       BSD

usleep(3C)																usleep(3C)

NAME

       usleep - suspend execution for interval in microseconds

SYNOPSIS

       #include <unistd.h>

       int usleep(useconds_t useconds);

       The usleep() function suspends the caller from execution for the number of microseconds specified by the useconds argument. The actual sus-
       pension time might be less than requested because any caught signal will terminate usleep() following execution of that	signal's  catching
       routine.  The suspension time might be longer than requested by an arbitrary amount because of the scheduling of other activity in the sys-
       tem.

       If the value of useconds is 0, then the call has no effect.

       The use of the usleep() function has no effect on the action or blockage of any signal. In  a  multithreaded  process,  only  the  invoking
       thread is suspended from execution.

       On completion, usleep() returns 0. There are no error retruns.

       No errors are returned.

USAGE

       The usleep() function is included for its historical usage.  The nanosleep(3RT) function is preferred over this function.

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Safe			   |
       +-----------------------------+-----------------------------+

       nanosleep(3RT), sleep(3C), attributes(5), standards(5)

								    16 Mar 2005 							usleep(3C)