Man Linux: Main Page and Category List


       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
       gethostname(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,
       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

       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
              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 instead.

       -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

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