PHP で HTTP リクエストを開始するにはどのような方法がありますか?

<?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(
        &#39;http&#39; => array(
            &#39;method&#39; => &#39;POST&#39;,
            &#39;header&#39; => &#39;Content-type:application/x-www-form-urlencoded&#39;,
            &#39;content&#39; => $postdata,
            &#39;timeout&#39; => 15 * 60 // 超时时间（单位:s）
        )
    );
    $context = stream_context_create($options);
    $result = file_get_contents($url, false, $context);
    return $result;
}
$post_data = array(
&#39;username&#39; => &#39;abcdef&#39;,
&#39;password&#39; => &#39;123456&#39;
);
send_post(&#39;http://xxx.com&#39;, $post_data);

<?php
$ch=curl_init(&#39;http://www.xxx.com/xx.html&#39;);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
curl_setopt($ch,CURLOPT_BINARYTRANSFER,true);
$output=curl_exec($ch);
$fh=fopen("out.html",&#39;w&#39;);
fwrite($fh,$output);
fclose($fh);

/**
 * 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;
}