GETHOSTID(2) Linux Programmer's Manual GETHOSTID(2)NAME
gethostid, sethostid - get or set the unique identifier of the current
host
SYNOPSIS
#include <unistd.h>
long gethostid(void);
int sethostid(long hostid);
DESCRIPTION
Get or set a unique 32-bit identifier for the current machine. The
32-bit identifier is intended to be unique among all UNIX systems in
existence. This normally resembles the Internet address for the local
machine, as returned by gethostbyname(3), and thus usually never needs
to be set.
The sethostid() call is restricted to the superuser.
The hostid argument is stored in the file /etc/hostid.
RETURN VALUEgethostid() returns the 32-bit identifier for the current host as set
by sethostid(2).
CONFORMING TO
4.2BSD; these functions were dropped in 4.4BSD. SVr4 includes geth‐
ostid() but not sethostid(). POSIX.1-2001 specifies gethostid() but
not sethostid().
FILES
/etc/hostid
EXAMPLE
id = gethostid ();
/* This is a no-op unless unsigned int is wider than 32 bits. */
id &= 0xffffffff;
SEE ALSOhostid(1), gethostbyname(3)Linux 0.99.13 1993-11-29 GETHOSTID(2)