# EventBufferEvent::connect

(PECL event >= 1.2.6-beta)

EventBufferEvent::connect — Connect buffer event's file descriptor to given address or UNIX socket

### 说明

public EventBufferEvent::connect( string `$addr` ): bool

Connect buffer event's file descriptor to given address(optionally with port), or a UNIX domain socket.

If socket is not assigned to the buffer event, this function allocates a new socket and makes it non-blocking internally.

To resolve DNS names(asyncronously), use EventBufferEvent::connectHost() method.

### 参数

`addr`

  Should contain an IP address with optional port number, or a path to UNIX domain socket. Recognized formats are:

      [IPv6Address]:port
      [IPv6Address]
      IPv6Address
      IPv4Address:port
      IPv4Address
      unix:path

  Note, `'unix:'` prefix is currently not case sensitive.

### 返回值

成功时返回 `true`， 或者在失败时返回 `false`。

### 示例

示例 #1 EventBufferEvent::connect() example

`<?php
/*
* 1. Connect to 127.0.0.1 at port 80
* by means of EventBufferEvent::connect().
*
* 2. Request /index.cphp via HTTP/1.0
* using the output buffer.
*
* 3. Asyncronously read the response and print it to stdout.
*/
/* Read callback */
function readcb($bev, $base) {
$input = $bev->getInput();
while (($n = $input->remove($buf, 1024)) > 0) {
echo $buf;
}
}
/* Event callback */
function eventcb($bev, $events, $base) {
if ($events & EventBufferEvent::CONNECTED) {
echo "Connected.\n";
} elseif ($events & (EventBufferEvent::ERROR | EventBufferEvent::EOF)) {
if ($events & EventBufferEvent::ERROR) {
echo "DNS error: ", $bev->getDnsErrorString(), PHP_EOL;
}
echo "Closing\n";
$base->exit();
exit("Done\n");
}
}
$base = new EventBase();
echo "step 1\n";
$bev = new EventBufferEvent($base, /* use internal socket */ NULL,
EventBufferEvent::OPT_CLOSE_ON_FREE | EventBufferEvent::OPT_DEFER_CALLBACKS);
if (!$bev) {
exit("Failed creating bufferevent socket\n");
}
echo "step 2\n";
$bev->setCallbacks("readcb", /* writecb */ NULL, "eventcb", $base);
$bev->enable(Event::READ | Event::WRITE);
echo "step 3\n";
/* Send request */
$output = $bev->getOutput();
if (!$output->add(
"GET /index.cphp HTTP/1.0\r\n".
"Connection: Close\r\n\r\n"
)) {
exit("Failed adding request to output buffer\n");
}
/* Connect to the host syncronously.
* We know the IP, and don't need to resolve DNS. */
if (!$bev->connect("127.0.0.1:80")) {
exit("Can't connect to host\n");
}
/* Dispatch pending events */
$base->dispatch();`

以上示例的输出类似于：

    step 1
    step 2
    step 3
    Connected.
    HTTP/1.1 200 OK
    Server: nginx/1.2.6
    Date: Sat, 09 Mar 2013 10:06:58 GMT
    Content-Type: text/html; charset=utf-8
    Connection: close
    X-Powered-By: PHP/5.4.11--pl2-gentoo

    sdfsdfsf
    Closing
    Done

示例 #2 Connect to UNIX domain socket which presumably is served by a server, read response from the server and output it to the console

`<?php
class MyUnixSocketClient {
private $base, $bev;
function __construct($base, $sock_path) {
$this->base = $base;
$this->bev = new EventBufferEvent($base, NULL, EventBufferEvent::OPT_CLOSE_ON_FREE,
array ($this, "read_cb"), NULL, array ($this, "event_cb"));
if (!$this->bev->connect("unix:$sock_path")) {
trigger_error("Failed to connect to socket `$sock_path'", E_USER_ERROR);
}
$this->bev->enable(Event::READ);
}
function __destruct() {
if ($this->bev) {
$this->bev->free();
$this->bev = NULL;
}
}
function dispatch() {
$this->base->dispatch();
}
function read_cb($bev, $unused) {
$in = $bev->input;
printf("Received %ld bytes\n", $in->length);
printf("----- data ----\n");
printf("%ld:\t%s\n", (int) $in->length, $in->pullup(-1));
$this->bev->free();
$this->bev = NULL;
$this->base->exit(NULL);
}
function event_cb($bev, $events, $unused) {
if ($events & EventBufferEvent::ERROR) {
echo "Error from bufferevent\n";
}
if ($events & (EventBufferEvent::EOF | EventBufferEvent::ERROR)) {
$bev->free();
$bev = NULL;
} elseif ($events & EventBufferEvent::CONNECTED) {
$bev->output->add("test\n");
}
}
}
if ($argc <= 1) {
exit("Socket path is not provided\n");
}
$sock_path = $argv[1];
$base = new EventBase();
$cl = new MyUnixSocketClient($base, $sock_path);
$cl->dispatch();
?>`

以上示例的输出类似于：

    Received 5 bytes
    ----- data ----
    5:  test

### 参见

- EventBufferEvent::connectHost() - Connects to a hostname with optionally asyncronous DNS resolving

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