PHP支持的由Daniel Stenberg创建的libcurl库允许你与各种的服务器使用各种类型的协议进行连接和通讯。libcurl目前支持http、https、ftp、 gopher、telnet、dict、file和ldap协议

libcurl同时也支持HTTPS认证、HTTP POST、HTTP PUT、 FTP 上传(这个也能通过PHP的FTP扩展完成)、HTTP 基于表单的上传、代理、cookies和用户名+密码的认证。
php的curl真的是相当好用，网上一搜索相关文章都是关于curl模拟登陆的，很少人提供模拟discuz发贴的源码。

 
<?php 
$discuz_url = 'http://127.0.0.1/discuz/';//论坛地址 
$login_url = $discuz_url .'logging.php?action=login';//登录页地址 

$post_fields = array(); 
//以下两项不需要修改 
$post_fields['loginfield'] = 'username'; 
$post_fields['loginsubmit'] = 'true'; 
//用户名和密码，必须填写 
$post_fields['username'] = 'tianxin'; 
$post_fields['password'] = '111111'; 
//安全提问 
$post_fields['questionid'] = 0; 
$post_fields['answer'] = ''; 
//@todo验证码 
$post_fields['seccodeverify'] = ''; 
//获取表单FORMHASH 
$ch = curl_init($login_url); 
curl_setopt($ch, CURLOPT_HEADER, 0); 
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 
$contents = curl_exec($ch); 
curl_close($ch); 
preg_match('/<input\s*type="hidden"\s*name="formhash"\s*value="(.*?)"\s*\/>/i', $contents, $matches); 
if(!empty($matches)) { 
$formhash = $matches[1]; 
} else { 
die('Not found the forumhash.'); 
} 

//POST数据，获取COOKIE,cookie文件放在网站的temp目录下 
$cookie_file = tempnam('./temp','cookie'); 
$ch = curl_init($login_url); 
curl_setopt($ch, CURLOPT_HEADER, 0); 
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 
curl_setopt($ch, CURLOPT_POST, 1); 
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_fields); 
curl_setopt($ch, CURLOPT_COOKIEJAR, $cookie_file); 
curl_exec($ch); 
curl_close($ch); 
//取到了关键的cookie文件就可以带着cookie文件去模拟发帖,fid为论坛的栏目ID 
$send_url = $discuz_url."post.php?action=newthread&fid=2"; 

$ch = curl_init($send_url); 
curl_setopt($ch, CURLOPT_HEADER, 0); 
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 
curl_setopt($ch, CURLOPT_COOKIEFILE, $cookie_file); 
$contents = curl_exec($ch); 
curl_close($ch); 
//这里的hash码和登陆窗口的hash码的正则不太一样，这里的hidden多了一个id属性 
preg_match('/<input\s*type="hidden"\s*name="formhash"\s*id="formhash"\s*value="(.*?)"\s*\/>/i', $contents, $matches); 
if(!empty($matches)) { 
$formhash = $matches[1]; 
} else { 
die('Not found the forumhash.'); 
} 

$post_data = array(); 
//帖子标题 
$post_data['subject'] = 'test2'; 
//帖子内容 
$post_data['message'] = 'test2'; 
$post_data['topicsubmit'] = "yes"; 
$post_data['extra'] = ''; 
//帖子标签 
$post_data['tags'] = 'test'; 
//帖子的hash码，这个非常关键！假如缺少这个hash码，discuz会警告你来路的页面不正确 
$post_data['formhash']=$formhash; 

$ch = curl_init($send_url); 
curl_setopt($ch, CURLOPT_REFERER, $send_url); //伪装REFERER 
curl_setopt($ch, CURLOPT_HEADER, 0); 
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 0); 
curl_setopt($ch, CURLOPT_COOKIEFILE, $cookie_file); 
curl_setopt($ch, CURLOPT_POST, 1); 
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data); 
$contents = curl_exec($ch); 
curl_close($ch); 
//清理cookie文件 
unlink($cookie_file); 
?>