Table of Contents

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 nisdomainname - show or set system's NIS/YP domain name ypdomainname - show or set the system's NIS/YP 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]

domainname [-v] [-F filename] [--file filename] [name]

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

dnsdomainname [-v]
nisdomainname [-v]
ypdomainname [-v]

Description

Hostname is the program that 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.

domainname, nisdomainname, ypdomainname will print the name of the system as returned by the getdomainname(2) function. This is also known as the YP/NIS domain name of the system.

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 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.
-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.

Files

/etc/hosts

Author

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

Table of Contents