Index for Section 4

Alphabetical listing for R

resolver(4)
NAME
  resolver - Internet name domain client

DESCRIPTION
  The resolver is a set of routines in the C library that provide access to
  the Internet Domain Name System.  The resolver configuration file
  (resolv.conf) contains information that is read by the resolver routines
  the first time they are invoked by a process. The file is designed to be
  read by humans and contains a list of keywords with values that provide
  various types of resolver information.

  The different configuration options are:

  nameserver
	    Internet address (in dot notation) of a name server that the
	    resolver should query. Up to MAXNS (currently 3) name servers may
	    be listed, one per keyword. If there are multiple servers, the
	    resolver library queries them in the order listed.	If no
	    nameserver entries are present, the default is to use the name
	    server on the local machine.  (The algorithm used is to try a
	    name server, and if the query times out, try the next, until out
	    of name servers, then repeat trying all the name servers until a
	    maximum number of retries are made).

  domain    Local domain name. Most queries for names within this domain can
	    use short names relative to the local domain. If no domain entry
	    is present, the domain is determined from the local hostname
	    returned by gethostname(); the domain part is taken to be
	    everything after the first dot (.). Finally, if the hostname does
	    not contain a domain part, the root domain is assumed.

  search    Search list for hostname lookup. By default, the search list
	    consists of the local domain name.	You can change this system
	    wide by specifying search keyword followed by a list of domain
	    names separated by spaces or tabs, or on a per-process basis by
	    specifying the LOCALDOMAIN environment variable followed by a
	    list of domain names separated by spaces or tabs.

	    Most resolver queries will be attempted using each component of
	    the search path in turn until a match is found.  This process
	    might be slow and generate a lot of network traffic, if the
	    servers for the listed domains are not local, and that queries
	    will time out if no server is available for one of the domains.

	    The search list is currently limited to six domains with a total
	    of 256 characters.

  options ndots:n
	    Option for hostname lookup.	 By default, when a hostname contains
	    one or more dots (.), resolver looks up the name as given before
	    applying the search list.  You can change this system wide by
	    specifying options keyword followed by ndots:n, or on a per-
	    process basis by specifying the RES_OPTIONS environment variable
	    followed by ndots:n.  The n specifies the minimum number of dots
	    a name must contain in order to be looked up as given before
	    applying the search list.  The range is from 0 to 15.


  The domain and search keywords are mutually exclusive.  If more than one
  instance of these keywords is present, the last instance will override.

  The keyword and value must appear on a single line, and the keyword (for
  example, nameserver) must start the line.  The value follows the keyword,
  separated by white space.

FILES
  /etc/resolv.conf

RELATED INFORMATION
  Functions: gethostbyname(3), res_mkquery(3), res_send(3), res_init(3),
  dn_comp(3), dn_expand(3)

  Files: hostname(5)

  Commands: named(8)