.Dd Nov 5, 2008
.Dt GETHOSTUUID \&2 "Mac OS X System Calls Manual"
.Os "Mac OS X"
.Sh NAME
.Nm gethostuuid
.Nd return a unique identifier for the current machine
.Sh SYNOPSIS
.In unistd.h
.Ft int
.Fo gethostuuid
.Fa "uuid_t id"
.Fa "const struct timespec *wait"
.Fc
.Sh DESCRIPTION
The
.Fn gethostuuid
function returns a 16-byte
.Ft uuid_t
specified by
.Fa id ,
that uniquely identifies the current machine.
Be aware that the hardware identifiers that
.Fn gethostuuid
uses to generate the UUID can themselves be modified.
.Pp
The
.Fa wait
argument is a pointer to a
.Ft "struct timespec"
that specifies the maximum time to wait for the result.
Setting the
.Fa tv_sec
and
.Fa tv_nsec
fields to zero means to wait indefinitely until it completes.
.Sh RETURN VALUES
The
.Fn gethostuuid
function returns zero on success or -1 on error.
.Sh ERRORS
The
.Fn gethostuuid
functions fails if:
.Bl -tag -width Er
.It Bq Er EFAULT
.Fa wait
points to memory that is not a valid part of the process
address space.
.It Bq Er EWOULDBLOCK
The
.Fa wait
timeout expired before the UUID could be obtained.
.El
.Sh SEE ALSO
.Xr uuid 3