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