HOSTNAME

NAME

hostname − show or set the system’s host name
dnsdomainname − show the system’s DNS domain name

SYNOPSIS

hostname [−v] [−a] [−−alias] [−d] [−−domain] [−f] [−−fqdn] [−i] [−−ip-address] [−−long] [−s] [−−short] [−y] [−−yp] [−−nis]

hostname [−v] [−F filename] [−−file filename] [hostname]

hostname [−v] [−h] [−−help] [−V] [−−version]

dnsdomainname [−v]

DESCRIPTION

Hostname is used to either set or display the current host or domain name of the system. This name is 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.

dnsdomainname will print the domain part of the FQDN (Fully Qualified Domain Name). The complete FQDN of the system is returned with hostname −−fqdn.

SET NAME
When called with one argument or with the −−file option, the commands set the host name or the NIS/YP domain name. Note that this is effective only until the next reboot. Edit /etc/hostname for permanent change.

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 network address(es) of the host.

−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.

−y, −−yp, −−nis

Display the NIS domain name. If a parameter is given (or −−file name ) then root can also set a new NIS domain.

NOTES

The address families hostname tries when looking up the FQDN, aliases and network addresses of the host are determined by the configuration of your resolver. For instance, on GNU Libc systems, the resolver can be instructed to try IPv6 lookups first by using the inet6 option in /etc/resolv.conf.

FILES

/etc/hosts /etc/hostname This file should only contain domain name and not the full FQDN.

AUTHORS

Peter Tobias, <tobias AT et-inf DOT fho-emden DOT de>
Bernd Eckenfels, <net-tools AT lina DOT inka DOT de> (NIS and manpage).