经常会有人问模拟登陆的问题,其实原理很简单,只要把SessionID保存下来就可以了,今天花了一个小时的时间写了一个函数,供大家参考,网站返回的头信息,具体网站具体分析。
源代码:
<?php
/*
* 得到网页内容
* 参数:$host [in] string
* 主机名称(例如: )
* 参数:$method [in] string
* 提交方法:POST, GET, HEAD ... 并加上相应的参数( 具体语法参见 RFC1945,RFC2068 )
* 参数:$str [in] string
* 提交的内容
* 参数:$sessid [in] string
* PHP的SESSIONID
*
* @返回 网页内容 string
*/
function GetWebContent($host, $method, $str, $sessid = @#@#)
{
$ip = gethostbyname($host);
$fp = fsockopen($ip, 80);
if (!$fp) return;
fputs($fp, "$method\r\n");
fputs($fp, "Host: $host\r\n");
if (!empty($sessid))
{
fputs($fp, "Cookie: PHPSESSID=$sessid; path=/;\r\n");
}
if ( substr(trim($method),0, 4) == "POST")
{
fputs($fp, "Content-Length: ". strlen($str) . "\r\n"); // 别忘了指定长度
}
fputs($fp, "Content-Type: application/x-www-form-urlencoded\r\n\r\n");
if ( substr(trim($method),0, 4) == "POST")
{
fputs($fp, $str."\r\n");
}
while(!feof($fp))
{
$response .= fgets($fp, 1024);
}
$hlen = strpos($response,"\r\n\r\n"); // LINUX下是 "\n\n"
$header = substr($response, 0, $hlen);
$entity = substr($response, $hlen + 4);
if ( preg_match(@#/PHPSESSID=([0-9a-z]+);/i@#, $header, $matches))
{
$a[@#sessid@#] = $matches[1];
}
if ( preg_match(@#/Location: ([0-9a-z\_\?\=\&\#\.]+)/i@#, $header, $matches))
{
$a[@#location@#] = $matches[1];
}
$a[@#content@#] = $entity;
fclose($fp);
return $a;
}
/* 构造用户名,密码字符串 */
$str = ("username=test&password=test");
$response = GetWebContent("localhost","POST /login.php HTTP/1.0", $str);
echo $response[@#location@#].$response[@#content@#]."<br>";
echo $response[@#sessid@#]."<br>";
if ( preg_match(@#/error\.php/i@#,$response[@#location@#]))
{
echo "登陆失败<br>";
} else {
echo "登陆成功<br>";
// 不可以访问user.php,因为不带sessid参数
$response = GetWebContent("localhost","GET /user.php HTTP/1.0", @#@#, @#@#);
echo $response[@#location@#]."<br>"; // 结果:error.php?errcode=2
// 可以访问user.php
$response = GetWebContent("localhost","GET /user.php HTTP/1.0", @#@#, $response[@#sessid@#]);
echo $response[@#location@#]."<br>"; // 结果:user.php
}
?>