Net::Domain(3pm) Perl Programmers Reference Guide Net::Domain(3pm)NAME
Net::Domain - Attempt to evaluate the current host's internet name and domain
SYNOPSIS
use Net::Domain qw(hostname hostfqdn hostdomain domainname);
DESCRIPTION
Using various methods attempt to find the Fully Qualified Domain Name (FQDN) of the current host. From this determine the host-name and the
host-domain.
Each of the functions will return undef if the FQDN cannot be determined.
hostfqdn ()
Identify and return the FQDN of the current host.
domainname ()
An alias for hostfqdn ().
hostname ()
Returns the smallest part of the FQDN which can be used to identify the host.
hostdomain ()
Returns the remainder of the FQDN after the hostname has been removed.
AUTHOR
Graham Barr <gbarr@pobox.com>. Adapted from Sys::Hostname by David Sundstrom <sunds@asictest.sc.ti.com>
COPYRIGHT
Copyright (c) 1995-1998 Graham Barr. All rights reserved. This program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.
perl v5.16.2 2012-08-26 Net::Domain(3pm)
Check Out this Related Man Page
HOSTNAME(1) Linux Programmer's Manual HOSTNAME(1)NAME
hostname - show or set the system's host name
domainname - show or set the system's NIS/YP domain name
dnsdomainname - show the system's DNS domain name
nodename - show or set the system's DECnet node name
SYNOPSIS
hostname [-v] [-a] [--alias] [-d] [--domain] [-f] [--fqdn] [-i] [--ip-address] [--long] [-s] [--short] [-y] [-n] [--node]
hostname [-v] [-F filename] [--file filename] [hostname]
domainname [-v] [-F filename] [--file filename] [name]
nodename [-v] [-F filename] [--file filename] [name]
hostname [-v] [-h] [--help] [-V] [--version]
dnsdomainname [-v]
DESCRIPTION
Hostname is the program that is used to either set or display the current host, domain or node name of the system. These names are used by
many of the networking programs to identify the machine. The domain name is also used by NIS/YP.
GET NAME
When called without any arguments, the program displays the current names:
hostname will print the name of the system as returned by the gethostname(2) function.
nodename will print the DECnet node name of the system as returned by the getnodename(2) function.
dnsdomainname will print the domain part of the FQDN (Fully Qualified Domain Name). The complete FQDN of the system is returned with host-
name --fqdn.
The function gethostname(2) is used to get the hostname. Only when the hostname -s is called will gethostbyname(3) be called. The differ-
ence in gethostname(2) and gethostbyname(3) is that gethostbyname(3) is network aware, so it consults /etc/nsswitch.conf and /etc/host.conf
to decide whether to read information in /etc/sysconfig/network or /etc/hosts the hostname is also set when the network interface is
brought up.
SET NAME
When called with one argument or with the --file option, the commands set the host name, the NIS/YP domain name or the node name.
Note, that only the super-user can change the names.
It is not possible to set the FQDN or the DNS domain name with the dnsdomainname command (see THE FQDN below).
The host name is usually set once at system startup in /etc/rc.d/rc.inet1 or /etc/init.d/boot (normally by reading the contents of a file
which contains the host name, e.g. /etc/hostname).
THE FQDN
You can't change the FQDN (as returned by hostname --fqdn) or the DNS domain name (as returned by dnsdomainname) with this command. The
FQDN of the system is the name that the resolver(3) returns for the host name.
Technically: The FQDN is the name gethostbyname(2) returns for the host name returned by gethostname(2). The DNS domain name is the part
after the first dot.
Therefore it depends on the configuration (usually in /etc/host.conf) how you can change it. Usually (if the hosts file is parsed before
DNS or NIS) you can change it in /etc/hosts.
OPTIONS -a, --alias
Display the alias name of the host (if used).
-d, --domain
Display the name of the DNS domain. Don't use the command domainname to get the DNS domain name because it will show the NIS domain
name and not the DNS domain name. Use dnsdomainname instead.
-F, --file filename
Read the host name from the specified file. Comments (lines starting with a `#') are ignored.
-f, --fqdn, --long
Display the FQDN (Fully Qualified Domain Name). A FQDN consists of a short host name and the DNS domain name. Unless you are using
bind or NIS for host lookups you can change the FQDN and the DNS domain name (which is part of the FQDN) in the /etc/hosts file.
-h, --help
Print a usage message and exit.
-i, --ip-address
Display the IP address(es) of the host.
-n, --node
Display the DECnet node name. If a parameter is given (or --file name ) the root can also set a new node name.
-s, --short
Display the short host name. This is the host name cut at the first dot.
-V, --version
Print version information on standard output and exit successfully.
-v, --verbose
Be verbose and tell what's going on.
FILES
/etc/hosts
AUTHOR
Peter Tobias, <tobias@et-inf.fho-emden.de>
Bernd Eckenfels, <net-tools@lina.inka.de> (NIS and manpage).
Steve Whitehouse, <SteveW@ACM.org> (DECnet support and manpage).
net-tools 28 Jan 1996 HOSTNAME(1)