.\" Copyright (c) 1983, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)gethostid.3 8.1 (Berkeley) 6/2/93 .\" $FreeBSD: src/lib/libc/compat-43/gethostid.3,v 1.14 2007/01/09 00:27:49 imp Exp $ .\" .Dd June 2, 1993 .Dt GETHOSTID 3 .Os .Sh NAME .Nm gethostid , .Nm sethostid .Nd get/set unique identifier of current host .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In unistd.h .Ft long .Fn gethostid void .Ft void .Fn sethostid "long hostid" .Sh DESCRIPTION The .Fn sethostid function establishes a 32-bit identifier for the current processor. The id, intended to be unique among all UNIX systems in existence, is normally a DARPA Internet address for the local machine. This call is allowed only to the super-user and is normally performed at boot time. .Pp The .Fn gethostid function returns the 32-bit identifier for the current processor. .Pp This function has been deprecated. The hostid should be set or retrieved by use of .Xr sysctl 3 . .Sh SEE ALSO .Xr gethostname 3 , .Xr sysctl 3 , .Xr sysctl 8 .Sh HISTORY The .Fn gethostid and .Fn sethostid syscalls appeared in .Bx 4.2 and were dropped in .Bx 4.4 . .Sh BUGS 32 bits for the identifier is too small.