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HOSTNAME(7)		 Miscellaneous Information Manual	     HOSTNAME(7)

NAME
     hostname -- host name 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

	   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 function is
     generally performed by the library  routine  gethostbyname(3).)   Hostnames
     are resolved by the Internet name resolver in the following fashion.

     If  the  name consists of a single component, i.e., 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 com-
     plete 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 pro-
     cessing.

     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 remain-
     ing from the local domain.  The search path can be changed from the default
     by a system-wide configuration file (see resolver(5)).

SEE ALSO
     gethostbyname(3), resolver(5)

HISTORY
     Hostname appeared in 4.2BSD.

FreeBSD 15.1			December 25, 2013		     HOSTNAME(7)
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