freebsd man page for nanosleep

NANOSLEEP(2)						      BSD System Calls Manual						      NANOSLEEP(2)

NAME
     nanosleep -- suspend process execution for an interval measured in nanoseconds

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <time.h>

     int
     nanosleep(const struct timespec *rqtp, struct timespec *rmtp);

DESCRIPTION
     The nanosleep() system call causes the calling thread to sleep until the time interval specified by rqtp has elapsed.  An unmasked signal
     will cause it to terminate the sleep early, regardless of the SA_RESTART value on the interrupting signal.

RETURN VALUES
     If the nanosleep() system call returns because the requested time has elapsed, the value returned will be zero.

     If the nanosleep() system call returns due to the delivery of a signal, the value returned will be -1, and the global variable errno will be
     set to indicate the interruption.	If rmtp is non-NULL, the timespec structure it references is updated to contain the unslept amount (the
     request time minus the time actually slept).

ERRORS
     The nanosleep() system call fails if:

     [EFAULT]		Either rqtp or rmtp points to memory that is not a valid part of the process address space.

     [EINTR]		The nanosleep() system call was interrupted by the delivery of a signal.

     [EINVAL]		The rqtp argument specified a nanosecond value less than zero or greater than or equal to 1000 million.

     [ENOSYS]		The nanosleep() system call is not supported by this implementation.

SEE ALSO
     sigsuspend(2), sleep(3)

STANDARDS
     The nanosleep() system call conforms to IEEE Std 1003.1b-1993 (``POSIX.1'').

BSD
								  April 17, 1997							       BSD