NAME | DESCRIPTION | SEE ALSO | COLOPHON
HOSTNAME(7) Linux Programmer's Manual HOSTNAME(7)
hostname - hostname resolution description
Hostnames are domains, where a domain is a hierarchical, dot-separated list of
subdomains; for example, the machine monet, in the Berkeley subdomain of the
EDU subdomain of the Internet would be represented as
monet.Berkeley.EDU
(with no trailing dot).
Hostnames are often used with network client and server programs, which must
generally translate the name to an address for use. (This task is generally
performed by either getaddrinfo(3) or the obsolete gethostbyname(3).)
Hostnames are resolved by the Internet name resolver in the following fashion.
If the name consists of a single component, that is, contains no dot, and if
the environment variable HOSTALIASES is set to the name of a file, that file
is searched for any string matching the input hostname. The file should
consist of lines made up of two white-space separated strings, the first of
which is the hostname alias, and the second of which is the complete hostname
to be substituted for that alias. If a case-insensitive match is found
between the hostname to be resolved and the first field of a line in the file,
the substituted name is looked up with no further processing.
If the input name ends with a trailing dot, the trailing dot is removed, and
the remaining name is looked up with no further processing.
If the input name does not end with a trailing dot, it is looked up by
searching through a list of domains until a match is found. The default
search list includes first the local domain, then its parent domains with at
least 2 name components (longest first). For example, in the domain
CS.Berkeley.EDU, the name lithium.CChem will be checked first as
lithium.CChem.CS.Berkeley.EDU and then as lithium.CChem.Berkeley.EDU.
Lithium.CChem.EDU will not be tried, as there is only one component remaining
from the local domain. The search path can be changed from the default by a
system-wide configuration file (see resolver(5)).
gethostbyname(3), resolver(5), mailaddr(7), named(8)
This page is part of release 3.21 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
Linux 2008-06-11 HOSTNAME(7)