Introduction to the cURL library function of PHP to capture web pages, POST data, and other _ PHP tutorials

The cURL library function of PHP captures web pages, POST data, and others. Whether you want to retrieve part of the data from a link or an XML file and import it to the database, you may simply get the webpage content, cURL is a powerful tool. Whether you want to retrieve part of the data from a link, or retrieve an XML file and import it to the database, you may simply get the webpage content, the reactor cURL is a powerful PHP library. This article describes how to use this PHP library.
Enable cURL settings
First, we must first determine whether PHP has enabled this library. you can use the php_info () function to obtain this information.

The code is as follows:

Phpinfo ();
?>

If you can see the following output on the webpage, it indicates that the cURL Library has been enabled.
If you see this, you need to set your PHP and enable this library. If you are on Windows, it is very simple. you need to modify the settings of your php. ini file, find php_curl.dll, and cancel the semicolon comment. As follows:
// Cancel the comment
Extension = php_curl.dll

If you are under Linux, you need to recompile your PHP for google ranking. during editing, you need to open the compilation parameter -- add the "-with-curl" parameter to the configure command.
A small example
If everything is ready, the following is a small routine:

The code is as follows:

// Initialize a cURL object
$ Curl = curl_init ();
// Set the URL you want to capture
Curl_setopt ($ curl, CURLOPT_URL, 'http: // jb51.net ');
// Set the header
Curl_setopt ($ curl, CURLOPT_HEADER, 1 );
// Set the cURL parameter to save the result to the string or output to the screen.
Curl_setopt ($ curl, CURLOPT_RETURNTRANSFER, 1 );
// Run cURL to request the webpage
$ Data = curl_exec ($ curl );
// Close the URL request
Curl_close ($ curl );
// Display the obtained data
Var_dump ($ data );

How to POST data
The above is the code for capturing web pages, and the following is to POST data to a web page. Suppose we have a form processing URL http://www.example.com/sendsms.php, which can accept two single table domain, one is the phone number, and the other is the SMS content.

The code is as follows:

$ PhoneNumber = '000000 ';
$ Message = 'This message was generated by curl and php ';
$ CurlPost = 'pnumber = '. urlencode ($ phoneNumber).' & MESSAGE = '. urlencode ($ message).' & SUBMIT = send ';
$ Ch = curl_init (); chain link fencing
Curl_setopt ($ ch, CURLOPT_URL, 'http: // www.example.com/sendSMS.php ');
Curl_setopt ($ ch, CURLOPT_HEADER, 1 );
Curl_setopt ($ ch, CURLOPT_RETURNTRANSFER, 1 );
Curl_setopt ($ ch, CURLOPT_POST, 1 );
Curl_setopt ($ ch, CURLOPT_POSTFIELDS, $ curlPost );
$ Data = curl_exec ();
Curl_close ($ ch );
?>

From the above procedure, we can see that using CURLOPT_POST to set the POST method of the HTTP protocol, instead of the GET method, and then setting the POST data with CURLOPT_POSTFIELDS.
About proxy servers
The following is an example of how to use the proxy server. Pay attention to the highlighted code. the code is very simple and I don't need to talk about it.

The code is as follows:

$ Ch = curl_init ();
Curl_setopt ($ ch, CURLOPT_URL, 'http: // www.example.com ');
Curl_setopt ($ ch, CURLOPT_HEADER, 1 );
Curl_setopt ($ ch, CURLOPT_RETURNTRANSFER, 1 );
Curl_setopt ($ ch, CURLOPT_HTTPPROXYTUNNEL, 1 );
Curl_setopt ($ ch, CURLOPT_PROXY, 'fakeproxy. com: 1080 ');
Curl_setopt ($ ch, CURLOPT_PROXYUSERPWD, 'User: password ');
$ Data = curl_exec ();
Curl_close ($ ch );
?>

　　
About SSL and Cookie
For SSL, that is, the HTTPS protocol, you only need to change the http: // in the CURLOPT_URL connection to https. Of course, the parameter CURLOPT_SSL_VERIFYHOST can be set as a verification site.
For Cookie, you need to understand the following three parameters:
CURLOPT_COOKIE: set a cookie in the face-to-face session.
CURLOPT_COOKIEJAR saves a Cookie when the session ends.
CURLOPT_COOKIEFILE: the Cookie file.
HTTP server authentication
Finally, let's take a look at the situation of HTTP server authentication.

The code is as follows:

$ Ch = curl_init ();
Curl_setopt ($ ch, CURLOPT_URL, 'http: // www.example.com ');
Curl_setopt ($ ch, CURLOPT_RETURNTRANSFER, 1 );
Curl_setopt ($ ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC );
Curl_setopt (CURLOPT_USERPWD, '[username]: [password]')
$ Data = curl_exec ();
Curl_close ($ ch );
?>

For more information, see the cURL manual.

Pipeline is a powerful function...