Usage analysis of get_meta_tags(), CURL and user-agent in PHP, curlagent_PHP tutorial

Usage analysis of get_meta_tags(), CURL and user-agent in php, curlagent

This article analyzes the usage of get_meta_tags(), CURL and user-agent in PHP with examples. Share it with everyone for your reference. The specific analysis is as follows:

The get_meta_tags() function is used to grab tags in the form of and load them One-dimensional array, name is the element subscript, content is the element value, the label in the above example can obtain the array: array('A'=>'1', 'b'=>'2'), others< The meta> tag is not processed, and this function only processes the tag, and the subsequent will no longer be processed, but the before will still be processed.

User-agent is part of the invisible header information submitted by the browser when requesting a web page from the server. The header information is an array that contains multiple information, such as local cache directories, cookies, etc., where user-agent is Browser type declaration, such as IE, Chrome, FF, etc.

When I grabbed the tag of a web page today, I always got a null value, but it was normal to directly check the source code of the web page. So I wondered whether the server was set to judge the output based on the header information. Try it first. Use get_meta_tags() to grab a local file, and then the local file writes the obtained header information to the file. The result is as follows, which is replaced with / for easy viewing. The code is as follows:

Copy code The code is as follows:

array (
'HTTP_HOST' => '192.168.30.205',
'PATH' => 'C:/Program Files/Common Files/NetSarang;C:/Program Files/NVIDIA Corporation/PhysX/Common;C:/Program Files/Common Files/Microsoft Shared/Windows Live;C:/Program Files/Intel/iCLS Client/;C:/Windows/system32;C:/Windows;C:/Windows/System32/Wbem;C:/Windows/System32/WindowsPowerShell/v1.0/;C:/Program Files/Intel /Intel(R) Management Engine Components/DAL;C:/Program Files/Intel/Intel(R) Management Engine Components/IPT;C:/Program Files/Intel/OpenCL SDK/2.0/bin/x86;C:/Program Files/Common Files/Thunder Network/KanKan/Codecs;C:/Program Files/QuickTime Alternative/QTSystem;C:/Program Files/Windows Live/Shared;C:/Program Files/QuickTime Alternative/QTSystem/; %JAVA_HOME%/ bin;%JAVA_HOME%/jre/bin;',
'SystemRoot' => 'C:/Windows',
'COMSPEC' => 'C:/Windows/system32/cmd.exe',
'PATHEXT' => '.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC',
'WINDIR' => 'C:/Windows',
'SERVER_SIGNATURE' => '',
'SERVER_SOFTWARE' => 'Apache/2.2.11 (Win32) PHP/5.2.8',
'SERVER_NAME' => '192.168.30.205',
'SERVER_ADDR' => '192.168.30.205',
'SERVER_PORT' => '80',
'REMOTE_ADDR' => '192.168.30.205',
'DOCUMENT_ROOT' => 'E:/wamp/www',
'SERVER_ADMIN' => 'admin@admin.com',
'SCRIPT_FILENAME' => 'E:/wamp/www/user-agent.php',
'REMOTE_PORT' => '59479',
'GATEWAY_INTERFACE' => 'CGI/1.1',
'SERVER_PROTOCOL' => 'HTTP/1.0',
'REQUEST_METHOD' => 'GET',
'QUERY_STRING' => '',
'REQUEST_URI' => '/user-agent.php',
'SCRIPT_NAME' => '/user-agent.php',
'PHP_SELF' => '/user-agent.php',
'REQUEST_TIME' => 1400747529,
)

Sure enough, there is no HTTP_USER_AGENT element in the array. Apache does not have UA when sending a request to another server. After checking the information, the get_meta_tags() function does not have the ability to forge UA, so we can only use other methods to solve it.

Later, I used CURL to obtain it and obtained the web page, but it was a little more troublesome to use. I first forged the UA, and then used regular expressions to analyze .

Forgery method, the code is as follows:

Copy code The code is as follows:

//Initialize a cURL
$curl = curl_init();

//Set the URL you need to crawl
curl_setopt($curl, CURLOPT_URL, 'http://localhost/user-agent.php');

//Set whether to output the file header to the browser, 0 does not output
curl_setopt($curl, CURLOPT_HEADER, 0);

//Set UA, here the browser's UA is forwarded to the server, you can also manually specify the value
curl_setopt($curl, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);

//Set cURL parameters to require the results to be returned to a string or output to the screen. 0 outputs the screen and returns the BOOL value of the operation result, 1 returns a string
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
// Run cURL to request the web page
$data = curl_exec($curl);

// Close URL request
curl_close($curl);

// Process the obtained data
var_dump($data);

I hope this article will be helpful to everyone’s PHP programming design.

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