這也是個老生常談的話題了，上午花了點時間把這個問題整理了一下。

一般來說用PHP來模擬post提交資料有三種方法，file_get_contents、curl和socket。

寫了個公用函式，專門用來列印post資料：

<?php
function pr() {
    $params = func_get_args();
    foreach ($params as $key => $value) {
        echo "<pre>";
        print_r($value);
        echo "</pre>";
    }
}

先寫一個post.php，用來接收post資料並打印出來：

<?php
require dirname(__FILE__).'/function.php';

if (isset($_POST) && !empty($_POST)) {
    pr($_POST);
} else {
    pr("NO POST DATA!");
}
 

下面是用file_get_contents來模擬post：

<?php
require dirname(__FILE__).'/function.php';

function file_get_contents_post($url, $post) {
    $options = array(
        'http' => array(
            'method' => 'POST',
            // 'content' => 'name=caiknife&[email protected]',
            'content' => http_build_query($post),
        ),
    );

    $result = file_get_contents($url, false, stream_context_create($options));

    return $result;
}

$data = file_get_contents_post("http://www.a.com/post/post.php", array('name'=>'caiknife', 'email'=>'
 
[email protected]'));

var_dump($data);

很簡單是吧？再來看看curl模擬post：

<?php
require dirname(__FILE__).'/function.php';

function curl_post($url, $post) {
    $options = array(
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_HEADER         => false,
        CURLOPT_POST           => true,
        CURLOPT_POSTFIELDS     => $post,
    );

    $ch = curl_init($url);
    curl_setopt_array($ch, $options);
    $result = curl_exec($ch);
    curl_close($ch);
    return $result;
}

$data = curl_post("http://www.a.com/post/post.php", array('name'=>'caiknife', 'email'=>'
 
[email protected]'));

var_dump($data);

最後是用socket來模擬post：

<?php
require dirname(__FILE__).'/function.php';

function socket_post($url, $post) {
    $urls = parse_url($url);
    if (!isset($urls['port'])) {
        $urls['port'] = 80;
    }

    $fp = fsockopen($urls['host'], $urls['port'], $errno, $errstr);
    if (!$fp) {
        echo "$errno, $errstr";
        exit();
    }

    $post = http_build_query($post);
    $length = strlen($post);
    $header = <<<HEADER
POST {$urls['path']} HTTP/1.1
Host: {$urls['host']}
Content-Type: application/x-www-form-urlencoded
Content-Length: {$length}
Connection: close

{$post}
HEADER;

    fwrite($fp, $header);
    $result = '';
    while (!feof($fp)) {
        // receive the results of the request
        $result .= fread($fp, 512);
    }
    $result = explode("\r\n\r\n", $result, 2);
    return $result[1];
}

$data = socket_post("http://www.a.com/post/post.php", array('name'=>'caiknife', 'email'=>'[email protected]'));

var_dump($data);

這三種方法最後看到的內容都是一樣的，但是在是用socket的時候，傳送header資訊時必須要注意header的完整資訊，比如content type和content length必須要有，connection: close和post資料之間要空一行，等等；而通過socket取得的內容是包含了header資訊的，要處理一下才能獲得真正的內容。