Index for Section 5

Alphabetical listing for H

hostname(5)
NAME
  hostname - Hostname resolution description

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 follows:

       monet.Berkeley.EDU

  Notice that there is 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 function is
  generally performed by the gethostbyname() function.) 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 HOSTALIASES environment variable is set to the name of a file, that
  file is searched for a 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 ALSO
  Functions: gethostbyname(3)

  Commands: named(8)