usleep(3) [osx 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 useconds);

DESCRIPTION

     The usleep() function suspends execution of the calling thread until either useconds microseconds have elapsed or a signal is delivered to
     the thread whose action is to invoke a signal-catching function or to terminate the thread or process.  The actual time slept may be longer,
     due to system latencies and possible limitations in the timer resolution of the hardware.

     This function is implemented, using nanosleep(2), by pausing for useconds 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.

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(3)						   BSD Library Functions Manual 						 USLEEP(3)

NAME

     usleep -- suspend execution for interval of 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 process until either the number of microseconds specified by microseconds have
     elapsed or a signal is delivered to the calling process and its action is to invoke a signal catching function or to terminate the process.
     The suspension time may be longer than requested due to the scheduling of other activity by the system.

     The microseconds argument must be less than 1,000,000.  If the value of microseconds is 0, then the call has no effect.

RETURN VALUES

     On successful completion, usleep() returns 0.  Otherwise, it returns -1 and sets errno to indicate the error.

ERRORS

     The usleep() function may fail if:

     [EINVAL]		The microseconds interval specified 1,000,000 or more microseconds.

SEE ALSO

     nanosleep(2), sleep(3)

STANDARDS

     The usleep() function conforms to X/Open Portability Guide Issue 4, Version 2 (``XPG4.2'').  It later appeared in the POSIX standard, but in
     IEEE Std 1003.1-2004 (``POSIX.1'') it was marked as legacy and the use of nanosleep(2) was recommended instead.  The IEEE Std 1003.1-2008
     (``POSIX.1'') revision removed usleep() from the specification.

HISTORY

     The usleep() function appeared in 4.3BSD.

BSD
								  April 29, 2010							       BSD