Man Pages

hostname(1) - phpMan hostname(1) - phpMan

Command: man perldoc info search(apropos)  


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
       dnsdomainname - show the system's DNS domain name
       nisdomainname - show or set system's NIS/YP domain name
       ypdomainname - show or set the system's NIS/YP 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] [-F filename] [--file filename] [hostname]


       domainname [-v] [-F filename] [--file filename] [name]


       nodename [-v] [-F filename] [--file filename] [name]


       hostname [-v] [-h] [--help] [-V] [--version]


       dnsdomainname [-v]
       nisdomainname [-v]
       ypdomainname [-v]


DESCRIPTION
       Hostname is the program that is used to either set or display the current host, domain or node name of the sys-
       tem.   These names are used by many of the networking programs to identify the machine. The domain name is also
       used by NIS/YP.


   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, nisdomainname, ypdomainname will print the name of the system as returned by  the  getdomainname(2)
       function. This is also known as the YP/NIS domain name of the system.


       dnsdomainname  will  print  the domain part of the FQDN (Fully Qualified Domain Name). The complete FQDN of the
       system is returned with hostname --fqdn.


       The function gethostname(2) is used to get the hostname.  When the hostname -a, -d, -f or  -i  is  called  will
       gethostbyname(3)  be called.  The difference in gethostname(2) and gethostbyname(3) is that gethostbyname(3) is
       network aware, so it consults /etc/nsswitch.conf and /etc/host.conf to decide whether to  read  information  in
       /etc/sysconfig/network or /etc/hosts

       To add another dimension to this, the hostname is also set when the network interface is brought up.


   SET NAME
       When called with one argument or with the --file option, the commands set the host name, the NIS/YP domain name
       or the node name.


       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/rc.d/rc.inet1 or /etc/init.d/boot (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  dnsdomain-
       name) 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 gethostbyname(2) 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).

       -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.

       -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 con-
              figured 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  IP  address(es)  of  the host. 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  net-
              work  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.

FILES
       /etc/hosts /etc/sysconfig/network

NOTE
       Note that hostname doesn't change anything permanently. After reboot original names from  /etc/hosts  are  used
       again.

AUTHOR
       Peter Tobias, <tobiasATet-inf.de>
       Bernd Eckenfels, <net-toolsATlina.de> (NIS and manpage).
       Steve Whitehouse, <SteveWATACM.org> (DECnet support and manpage).




net-tools                         28 Jan 1996                      HOSTNAME(1)