.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