Technical Notes

Manpages - hostname.1

NAME

hostname - show or set the system's host name
dnsdomainname - show the system's DNS domain name
domainname - show or set the system's NIS/YP domain name
nisdomainname - show or set system's NIS/YP domain name
nodename - show or set the system's DECnet node name
ypdomainname - show or set the system's NIS/YP domain name

SYNOPSIS

hostname [*-v*] [*-s*|*–short*]

hostname [*-v*] [*-a*|*–alias*] [*-d*|*–domain*] [*-f*|*–fqdn*|*–long*] [*-i*|*–ip-address*]

hostname [*-v*] [*-y*|*–yp*|*–nis*] [*-n*|*–node*]

hostname [*-v*] [*-F filename*|*–file filename*] [/newname/]

domainname [*-v*] [*-F filename*|*–file filename*] [/newname/]

nodename [*-v*] [*-F filename*|*–file filename*] [/newname/]

hostname [*-v*|*–verbose*] [*-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 system. 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.

nodename will print the DECnet node name of the system as returned by the *getnodename*(2) function.

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

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 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 canonical name returned by *gethostbyname2*(2) when resolving the result of the *gethostname*(2) name. 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. If hosts is the first lookup method, you can change the FQDN in /etc/hosts.

OPTIONS

-a, –alias
Display the alias name of the host (if used).
-d, –domain
Display the name of the DNS domain (this is the FQDN without the segment up to the first dot). This is equivalent to using the dnsdomainname command.
-F, –file filename
Read the new 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 name including the DNS domain.
-h, –help
Print a usage message and exit.
-i, –ip-address
Display the IP address(es) of the host.
-n, –node
Display the DECnet node name. If a parameter is given (or –file name ) the root can also set a new node name.
-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/hostname /etc/hosts /etc/host.conf

AUTHOR

Peter Tobias, <[email protected]>
Bernd Eckenfels, <[email protected]> (NIS and manpage).
Steve Whitehouse, <[email protected]> (DECnet support and manpage).