HOSTNAME(1) Linux Programmer's Manual HOSTNAME(1)
hostname - show or set the system's host name
domainname - show or set the system's NIS/YP domain name
ypdomainname - show or set the system's NIS/YP domain name
nisdomainname - show or set the system's NIS/YP domain name
dnsdomainname - show the system's DNS domain name
hostname [-v] [-a] [--alias] [-d] [--domain] [-f] [--fqdn] [-A] [--all-fqdns] [-i] [--ip-
address] [-I] [--all-ip-addresses] [--long] [-s] [--short] [-y] [--yp] [--nis]
hostname [-v] [-b] [--boot] [-F filename] [--file filename] [hostname]
hostname [-v] [-h] [--help] [-V] [--version]
domainname [nisdomain] [-F file]
ypdomainname [nisdomain] [-F file]
nisdomainname [nisdomain] [-F file]
Hostname is used to display the system's DNS name, and to display or set its hostname or
NIS domain 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 will print the NIS domainname of the system. domainname uses the gethost-
name(2) function, while ypdomainname and nisdomainname use the yp_get_default_domain(3).
dnsdomainname will print the domain part of the FQDN (Fully Qualified Domain Name). The
complete FQDN of the system is returned with hostname --fqdn (but see the warnings in sec-
tion THE FQDN below).
When called with one argument or with the --file option, the commands set the host name or
the NIS/YP domain name. hostname uses the sethostname(2) function, while all of the three
domainname, ypdomainname and nisdomainname use setdomainname(2). 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/init.d/hostname.sh (normally
by reading the contents of a file which contains the host name, e.g. /etc/hostname).
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 getaddrinfo(3) 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
If a machine has multiple network interfaces/addresses or is used in a mobile environment,
then it may either have multiple FQDNs/domain names or none at all. Therefore avoid using
hostname --fqdn, hostname --domain and dnsdomainname. hostname --ip-address is subject to
the same limitations so it should be avoided as well.
Display the alias name of the host (if used). This option is deprecated and should
not be used anymore.
Always set a hostname; this allows the file specified by -F to be non-existant or
empty, in which case the default hostname localhost will be used if none is yet
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. Ssee the warnings in section THE FQDN above, and
avoid using this option.
-F, --file filename
Read the host name from the specified file. Comments (lines starting with a `#')
-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. See the warnings in section THE FQDN above, and avoid using this
option; use hostname --all-fqdns instead.
Displays all FQDNs of the machine. This option enumerates all configured network
addresses on all configured network interfaces, and translates them to DNS domain
names. Addresses that cannot be translated (i.e. because they do not have an appro-
priate reverse DNS entry) are skipped. Note that different addresses may resolve to
the same name, therefore the output may contain duplicate entries. Do not make any
assumptions about the order of the output.
Print a usage message and exit.
Display the network address(es) of the host name. Note that this works only if the
host name can be resolved. Avoid using this option; use hostname --all-ip-addresses
Display all network addresses of the host. This option enumerates all configured
addresses on all network interfaces. The loopback interface and IPv6 link-local
addresses are omitted. Contrary to option -i, this option does not depend on name
resolution. Do not make any assumptions about the order of the output.
Display the short host name. This is the host name cut at the first dot.
Print version information on standard output and exit successfully.
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.
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.
/etc/hostname This file should only contain the hostname and not the full FQDN.
Peter Tobias, <firstname.lastname@example.org>
Bernd Eckenfels, <email@example.com> (NIS and manpage).
Michael Meskes, <firstname.lastname@example.org>
net-tools 2009-09-16 HOSTNAME(1)