*BASH User Commands Ubuntu 10.04.4 LTS Server coreutils
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]

       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

       hostname  will print the name of the system as returned by the gethost-
       name(2) function.

       domainname will print the NIS domainname  of  the  system.   domainname
       uses  the gethostname(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 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,  ypdomain-
       name and nisdomainname use setdomainname(2).  Note, that this is effec-
       tive only until the next  reboot.   Edit  /etc/hostname  for  permanent

       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 dns-
       domainname 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

       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 /etc/hosts.

       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 set.

       -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 inter-
              faces, and translates them to DNS domain names.  Addresses  that
              cannot be translated (i.e. because they do not have an appropri-
              ate  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 instead.

       -I, --all-ip-addresses
              Display  all  network addresses of the host. This option enumer-
              ates 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 reso-
              lution.  Do not make any assumptions about the order of the out-

       -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 success-

       -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/hostname  This  file  should only contain the hostname and not the
       full FQDN.

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

net-tools                         2009-09-16                       HOSTNAME(1)