# The EventDnsBase class

(PECL event >= 1.2.6-beta)

## Introduction

Represents Libevent's DNS base structure. Used to resolve DNS asyncronously, parse configuration files like resolv.conf etc.

## Class synopsis

final EventDnsBase {
/* Constants */
const integer OPTION_SEARCH = 1 ;
const integer OPTION_NAMESERVERS = 2 ;
const integer OPTION_MISC = 4 ;
const integer OPTION_HOSTSFILE = 8 ;
const integer OPTIONS_ALL = 15 ;
/* Methods */
public addNameserverIp ( string `$ip` ) : bool
public addSearch ( string `$domain` ) : void
public clearSearch ( void ) : void
public __construct ( EventBase `$base` , bool `$initialize` )
public countNameservers ( void ) : int
public loadHosts ( string `$hosts` ) : bool
public parseResolvConf ( int `$flags` , string `$filename` ) : bool
public setOption ( string `$option` , string `$value` ) : bool
public setSearchNdots ( int `$ndots` ) : bool
}

## Predefined Constants

`EventDnsBase::OPTION_SEARCH`

  Tells to read the domain and search fields from the resolv.conf file and the ndots option, and use them to decide which domains(if any) to search for hostnames that aren’t fully-qualified.

`EventDnsBase::OPTION_NAMESERVERS`

  Tells to learn the nameservers from the resolv.conf file.

`EventDnsBase::OPTION_MISC`

`EventDnsBase::OPTION_HOSTSFILE`

  Tells to read a list of hosts from /etc/hosts as part of loading the resolv.conf file.

`EventDnsBase::OPTIONS_ALL`

  Tells to learn as much as it can from the resolv.conf file.

## Table of Contents

- EventDnsBase::addNameserverIp — Adds a nameserver to the DNS base
- EventDnsBase::addSearch — Adds a domain to the list of search domains
- EventDnsBase::clearSearch — Removes all current search suffixes
- EventDnsBase::__construct — Constructs EventDnsBase object
- EventDnsBase::countNameservers — Gets the number of configured nameservers
- EventDnsBase::loadHosts — Loads a hosts file (in the same format as /etc/hosts) from hosts file
- EventDnsBase::parseResolvConf — Scans the resolv.conf-formatted file
- EventDnsBase::setOption — Set the value of a configuration option
- EventDnsBase::setSearchNdots — Set the 'ndots' parameter for searches