EventBufferEvent::connectHost

(PECL event >= 1.2.6-beta)

Connects to a hostname with optionally asyncronous DNS resolving

public bool EventBufferEvent::connectHost ( EventDnsBase $dns_base , string $hostname , int $port [, int $family = EventUtil::AF_UNSPEC ] )

Resolves the DNS name hostname, looking for addresses of type family ( EventUtil::AF_* constants). If the name resolution fails, it invokes the event callback with an error event. If it succeeds, it launches a connection attempt just as EventBufferEvent::connect() would.

dns_base is optional. May be NULL, or an object created with EventDnsBase::__construct() . For asyncronous hostname resolving pass a valid event dns base resource. Otherwise the hostname resolving will block.

Note:

EventDnsBase is available only if Event configured --with-event-extra ( event_extra library, libevent protocol-specific functionality support including HTTP, DNS, and RPC ).

Note:

EventBufferEvent::connectHost() requires libevent-2.0.3-alpha or greater.

Parameters:

dns_base

Object of EventDnsBase in case if DNS is to be resolved asyncronously. Otherwise NULL.

hostname

Hostname to connect to. Recognized formats are:

www.example.com (hostname)
 1.2.3.4 (ipv4address)
 ::1 (ipv6address)
[::1] ([ipv6address])

port

Port number

family

Address family. EventUtil::AF_UNSPEC , EventUtil::AF_INET , or EventUtil::AF_INET6 . See EventUtil constants .

Returns:

Returns TRUE on success. Otherwise FALSE.

Examples:

EventBufferEvent::connectHost() example

<?php
/*Readcallback*/
functionreadcb($bev,$base){
//$input=$bev->input;//$bev->getInput();

//$pos=$input->search("TTP");
$pos=$bev->input->search("TTP");

while(($n=$bev->input->remove($buf,1024))>0){
echo$buf;
}
}

/*Eventcallback*/
functioneventcb($bev,$events,$base){
if($events&EventBufferEvent::CONNECTED){
echo"Connected.\n";
}elseif($events&(EventBufferEvent::ERROR|EventBufferEvent::EOF)){
if($events&EventBufferEvent::ERROR){
echo"DNSerror:",$bev->getDnsErrorString(),PHP_EOL;
}

echo"Closing\n";
$base->exit();
exit("Done\n");
}
}

$base=newEventBase();

$dns_base=newEventDnsBase($base,TRUE);//We'lluseasyncDNSresolving
if(!$dns_base){
exit("FailedtoinitDNSBase\n");
}

$bev=newEventBufferEvent($base,/*useinternalsocket*/NULL,
EventBufferEvent::OPT_CLOSE_ON_FREE|EventBufferEvent::OPT_DEFER_CALLBACKS,
"readcb",/*writecb*/NULL,"eventcb",$base
);
if(!$bev){
exit("Failedcreatingbuffereventsocket\n");
}

//$bev->setCallbacks("readcb",/*writecb*/NULL,"eventcb",$base);
$bev->enable(Event::READ|Event::WRITE);

$output=$bev->output;//$bev->getOutput();
if(!$output->add(
"GET{$argv[2]}HTTP/1.0\r\n".
"Host:{$argv[1]}\r\n".
"Connection:Close\r\n\r\n"
)){
exit("Failedaddingrequesttooutputbuffer\n");
}

if(!$bev->connectHost($dns_base,$argv[1],80,EventUtil::AF_UNSPEC)){
exit("Can'tconnecttohost{$argv[1]}\n");
}

$base->dispatch();
?>

The above example will output something similar to:

Connected.
HTTP/1.0 301 Moved Permanently
Location: http://www.google.co.uk/
Content-Type: text/html; charset=UTF-8
Date: Sat, 09 Mar 2013 12:21:19 GMT
Expires: Mon, 08 Apr 2013 12:21:19 GMT
Cache-Control: public, max-age=2592000
Server: gws
Content-Length: 221
X-XSS-Protection: 1; mode=block
X-Frame-Options: SAMEORIGIN

<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>301 Moved</TITLE></HEAD><BODY>
<H1>301 Moved</H1>
The document has moved
<A HREF="http://www.google.co.uk/">here</A>.
</BODY></HTML>
Closing
Done