Manual: nisdomainname

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	 [-a|--alias]  [-d|--domain]  [-f|--fqdn|--long]  [-A|--all-fqdns] [-i|--ip-address] [-I|--all-ip-addresses]
       [-s|--short] [-y|--yp|--nis]
       hostname [-b|--boot] [-F|--file filename] [hostname]
       hostname [-h|--help] [-V|--version]

       domainname [nisdomain] [-F file]
       ypdomainname [nisdomain] [-F file]
       nisdomainname [nisdomain] [-F file]

       dnsdomainname

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 ypdomain‐
       name and nisdomainname use the getdomainname(2).

       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).

   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 set‐
       domainname(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).

   THE FQDN
       The FQDN (Fully Qualified Domain Name) of the system is the name that the resolver(3) returns for the host name, such
       as, ursula.example.com.	It is usually the hostname followed by the DNS domain name (the part after the	first  dot).
       You can check the FQDN using hostname --fqdn or the domain name using dnsdomainname.

       You cannot change the FQDN with hostname or dnsdomainname.

       The  recommended	 method	 of  setting the FQDN is to make the hostname be an alias for the fully qualified name using
       /etc/hosts, DNS, or NIS. For example, if the hostname was "ursula", one might have a line in /etc/hosts which reads

	      127.0.1.1	   ursula.example.com ursula

       Technically: The FQDN is the name getaddrinfo(3) returns for the host name returned by gethostname(2).  The  DNS	 do‐
       main name is the part after the first dot.

       Therefore  it depends on the configuration of the resolver (usually in /etc/host.conf) how you can change it. Usually
       the hosts file is parsed before DNS or NIS, so it is most common to change the FQDN 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 dnsdomain‐
       name.  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.

       -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 IP 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.

       -b, --boot
	      Always set a hostname; this allows the file specified by -F to be non-existent or empty, in which case the de‐
	      fault 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. See the warnings in sec‐
	      tion THE FQDN above, and avoid using this option.

       -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 use hostname --all-
	      fqdns instead wherever possible.

       -F, --file filename
	      Read the host name from the specified file. Comments (lines starting with a `#') are ignored.

       -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 in‐
	      terfaces. 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.

       -y, --yp, --nis
	      Display the NIS domain name. If a parameter is given (or --file name ) then root can also set a  new  NIS	 do‐
	      main.

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

NOTES
       The  address  families  hostname tries when looking up the FQDN, aliases and network addresses of the host are deter‐
       mined 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/hostname Historically this file was supposed to only contain the hostname and not the full canonical FQDN. Nowa‐
       days most software is able to cope with a full FQDN here. This file is read at boot time by the system initialization
       scripts to set the hostname.

       /etc/hosts Usually, this is where one sets the domain name by aliasing the host name to the FQDN.

AUTHORS
       Peter Tobias, 
       Bernd Eckenfels,  (NIS and manpage).
       Michael Meskes, 

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