sunos man page for usleep

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)