file_get_contents版本：

<?php
/**
 * 发送post请求
 * @param string $url 请求地址
 * @param array $post_data post键值对数据
 * @return string
 */
function send_post($url, $post_data) {

	$postdata = http_build_query($post_data);
	$options = array(
		'http' => array(
			'method' => 'POST',
			'header' => 'Content-type:application/x-www-form-urlencoded',
			'content' => $postdata,
			'timeout' => 15 * 60 // 超时时间（单位:s）
		)
	);
	$context = stream_context_create($options);
	$result = file_get_contents($url, false, $context);

	return $result;
}

使用如下：

$post_data = array(
	'username' => 'stclair2201',
	'password' => 'handan'
);
send_post('http://blog.snsgou.com', $post_data);

实战经验：

当我利用上述代码给另一台服务器发送http请求时，发现，如果服务器处理请求时间过长，本地的PHP会中断请求，即所谓的超时中断，第一个怀疑的是PHP本身执行时间的超过限制，但想想也不应该，因为老早就按照这篇文章设置了“PHP执行时间限制”（【推荐】PHP上传文件大小限制大全 ），仔细琢磨，想想，应该是http请求本身的一个时间限制，于是乎，就想到了怎么给http请求时间限制搞大一点。。。。。。查看PHP手册，果真有个参数 “ timeout ”，默认不知道多大，当把它的值设大一点，问题得已解决，弱弱地做个笔记~~~

Socket版本:

/**
 * Socket版本
 * 使用方法：
 * $post_string = "app=socket&version=beta";
 * request_by_socket('blog.snsgou.com', '/restServer.php', $post_string);
 */
function request_by_socket($remote_server,$remote_path,$post_string,$port = 80,$timeout = 30) {
	$socket = fsockopen($remote_server, $port, $errno, $errstr, $timeout);
	if (!$socket) die("$errstr($errno)");
	fwrite($socket, "POST $remote_path HTTP/1.0");
	fwrite($socket, "User-Agent: Socket Example");
	fwrite($socket, "HOST: $remote_server");
	fwrite($socket, "Content-type: application/x-www-form-urlencoded");
	fwrite($socket, "Content-length: " . （strlen($post_string) + 8） . "");
	fwrite($socket, "Accept:*/*");
	fwrite($socket, "");
	fwrite($socket, "mypost=$post_string");
	fwrite($socket, "");
	$header = "";
	while ($str = trim(fgets($socket, 4096))) {
		$header .= $str;
	}

	$data = "";
	while (!feof($socket)) {
		$data .= fgets($socket, 4096);
	}

	return $data;
}

Curl版本:

/**
 * Curl版本
 * 使用方法：
 * $post_string = "app=request&version=beta";
 * request_by_curl('http://blog.snsgou.com/restServer.php', $post_string);
 */
function request_by_curl($remote_server, $post_string) {
	$ch = curl_init();
	curl_setopt($ch, CURLOPT_URL, $remote_server);
	curl_setopt($ch, CURLOPT_POSTFIELDS, 'mypost=' . $post_string);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
	curl_setopt($ch, CURLOPT_USERAGENT, "snsgou.com's CURL Example beta");
	$data = curl_exec($ch);
	curl_close($ch);

	return $data;
}

Curl版本(2)

/**
 * 发送HTTP请求
 *
 * @param string $url 请求地址
 * @param string $method 请求方式 GET/POST
 * @param string $refererUrl 请求来源地址
 * @param array $data 发送数据
 * @param string $contentType 
 * @param string $timeout
 * @param string $proxy
 * @return boolean
 */
function send_request($url, $data, $refererUrl = '', $method = 'GET', $contentType = 'application/json', $timeout = 30, $proxy = false) {
	$ch = null;
	if('POST' === strtoupper($method)) {
		$ch = curl_init($url);
		curl_setopt($ch, CURLOPT_POST, 1);
		curl_setopt($ch, CURLOPT_HEADER,0 );
		curl_setopt($ch, CURLOPT_FRESH_CONNECT, 1);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);
		curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
		if ($refererUrl) {
			curl_setopt($ch, CURLOPT_REFERER, $refererUrl);
		}
		if($contentType) {
			curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type:'.$contentType));
		}
		if(is_string($data)){
			curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
		} else {
			curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));
		}
	} else if('GET' === strtoupper($method)) {
		if(is_string($data)) {
			$real_url = $url. (strpos($url, '?') === false ? '?' : ''). $data;
		} else {
			$real_url = $url. (strpos($url, '?') === false ? '?' : ''). http_build_query($data);
		}

		$ch = curl_init($real_url);
		curl_setopt($ch, CURLOPT_HEADER, 0);
		curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type:'.$contentType));
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
		if ($refererUrl) {
			curl_setopt($ch, CURLOPT_REFERER, $refererUrl);
		}
	} else {
		$args = func_get_args();
		return false;
	}

	if($proxy) {
		curl_setopt($ch, CURLOPT_PROXY, $proxy);
	}
	$ret = curl_exec($ch);
	$info = curl_getinfo($ch);
	$contents = array(
			'httpInfo' => array(
					'send' => $data,
					'url' => $url,
					'ret' => $ret,
					'http' => $info,
			)
	);

	curl_close($ch);
	return $ret;
}

调用 WCF接口 的一个例子：$json = restRequest($r_url,'POST', json_encode($data));