GETHOSTID(3) BSD Programmer's Manual GETHOSTID(3)
gethostid, sethostid - get/set unique identifier of current host
#include <unistd.h> long gethostid(void); int sethostid(long hostid);
The sethostid() function establishes a 32-bit identifier for the current processor that is intended to be unique among all UNIX systems in ex- istence. This is normally a DARPA Internet address for the local machine. This call is allowed only to the superuser and is normally performed at boot-time. gethostid() returns the 32-bit identifier for the current processor. This function has been deprecated. The hostid should be set or retrieved by use of sysctl(3).
gethostname(3), sysctl(3), sysctl(8)
The gethostid() and sethostid() syscalls appeared in 4.2BSD and were dropped in 4.4BSD.
32 bits for the identifier is too small. MirBSD #10-current June 2, 1993 1