| NAME | DESCRIPTION | SEE ALSO | COLOPHON | The Linux Programming Interface |
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 domain would be represented as
"monet.Berkeley.EDU".
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 3.51 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 2010-11-07 HOSTNAME(7)
HTML rendering created 2013-05-17 by Michael Kerrisk, author of The Linux Programming Interface, maintainer of the Linux man-pages project
Hosting by jambit GmbH