Provided by: hostname_3.06ubuntu1_amd64 bug


       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]

       dnsdomainname [-v]


       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
       gethostname(2)    function,    while    ypdomainname    and    nisdomainname    use    the

       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
       section 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/ (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.


       -a, --alias
              Display the alias name of the host (if used). This option is deprecated and  should
              not be used anymore.

       -b, --boot
              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

       -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. 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  `#')
              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. See the warnings in section THE FQDN above, and avoid  using  this
              option; use hostname --all-fqdns instead.

       -A, --all-fqdns
              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
              appropriate 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.

       -h, --help
              Print a usage message and exit.

       -i, --ip-address
              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

       -I, --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.

       -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.


       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, <>
       Bernd Eckenfels, <> (NIS and manpage).
       Michael Meskes, <>