PHP Cookbook读书笔记 – 第13章Web自动化

通过GET获得一个指定url的页面内容 有3种方式来获取一个URL的内容： PHP提供的文件函数file_get_contents() cURL扩展 PEAR中的HTTP_Request类 //方式1$page = file_get_contents('http://www.example.com/robots.txt');//方式2$c = curl_init('http://www.ex

通过GET获得一个指定url的页面内容

有3种方式来获取一个URL的内容：

1. PHP提供的文件函数file_get_contents()
2. cURL扩展
3. PEAR中的HTTP_Request类

//方式1
$page = file_get_contents('http://www.example.com/robots.txt');

//方式2
$c = curl_init('http://www.example.com/robots.txt');
curl_setopt($c, CURLOPT_RETURNTRANSFER, true);
$page = curl_exec($c);
curl_close($c);

//方式3
require_once 'HTTP/Request.php';
$r = new HTTP_Request('http://www.example.com/robots.txt');
$r->sendRequest();
$page = $r->getResponseBody();

可以通过这些方式来获取XML文档，通过结合http_build_query()来建立一个查询字符串，可以通过url中加入username@password的形式来访问受保护的页面，通过cURL和PEAR的HTTP_Client类来跟踪重定向。

通过POST获得一个URL

让PHP模拟发送一个POST请求并获得服务器的反馈内容

//1
$url = 'http://www.example.com/submit.php';
$body = 'monkey=uncle&rhino=aunt';
$options = array('method' => 'POST', 'content' => $body);
$context = stream_context_create(array('http' => $options));
print file_get_contents($url, false, $context);

//2
$url = 'http://www.example.com/submit.php';
$body = 'monkey=uncle&rhino=aunt';
$c = curl_init($url);
curl_setopt($c, CURLOPT_POST, true);
curl_setopt($c, CURLOPT_POSTFIELDS, $body);
curl_setopt($c, CURLOPT_RETURNTRANSFER, true);
$page = curl_exec($c);
curl_close($c);

//3
require 'HTTP/Request.php';
$url = 'http://www.example.com/submit.php';
$r = new HTTP_Request($url);
$r->setMethod(HTTP_REQUEST_METHOD_POST);
$r->addPostData('monkey','uncle');
$r->addPostData('rhino','aunt');
$r->sendRequest();
$page = $r->getResponseBody();

通过Cookie获得一个URL

//2
$c = curl_init('http://www.example.com/needs-cookies.php');
curl_setopt($c, CURLOPT_COOKIE, 'user=ellen; activity=swimming');
curl_setopt($c, CURLOPT_RETURNTRANSFER, true);
$page = curl_exec($c);
curl_close($c);

//3
require 'HTTP/Request.php';
$r = new HTTP_Request('http://www.example.com/needs-cookies.php');
$r->addHeader('Cookie','user=ellen; activity=swimming');
$r->sendRequest();
$page = $r->getResponseBody();

通过Header获得一个URL

通过修改header中的信息可以来伪造 Referer 或 User-Agent 后请求目标URL，不少防盗链网站经常会采用判断Referer中的信息来源决定是否允许下载或访问资源。需要具备一些HTTP的HEADER背景知识。

标记网页

其实这个代码经过简单修改还可以应用到替换网页中的敏感关键字，这在天朝是很有用的一个功能

$body = '

I like pickles and herring.

A pickle picture

I have a herringbone-patterned toaster cozy.

Herring is not a real HTML element!
';

$words = array('pickle','herring');
$patterns = array();
$replacements = array();
foreach ($words as $i => $word) {
    $patterns[] = '/' . preg_quote($word) .'/i';
    $replacements[] = "\\0";
}

// Split up the page into chunks delimited by a
// reasonable approximation of what an HTML element
// looks like.
$parts = preg_split("{(])*>)}",
                    $body,
                    -1,  // Unlimited number of chunks
                    PREG_SPLIT_DELIM_CAPTURE);
foreach ($parts as $i => $part) {
    // Skip if this part is an HTML element
    if (isset($part[0]) && ($part[0] == 's
    $parts[$i] = preg_replace($patterns, $replacements, $part);
}

// Reconstruct the body
$body = implode('',$parts);

print $body;