HOSTNAME(1)						     Linux Programmer's Manual						       HOSTNAME(1)

NAME

       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

SYNOPSIS

       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]

DESCRIPTION

       Hostname is used to display the system's DNS name, and to display or set its hostname or NIS domain name.

   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 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 host-
       name --fqdn (but see the warnings in section THE FQDN below).

   SET NAME
       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 effec-
       tive 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).

   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 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.

OPTIONS

       -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  local-
	      host 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 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.

NOTES

       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.

FILES

       /etc/hosts

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

AUTHORS

       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)