php curl learning summary

Description: Use curl to quickly crawl web pages, simulate POST, GET requests, of course, it is not only some encapsulation of the HTTP protocol, but also supports FTP, proxy, HTTPS, LDAP and other applications. Curl is not unique to PHP, it is available in many languages. If something is easy to use, it will naturally be promoted, just like log4j many years ago. It was just a JAVA version, and then log4c, log4c++?? The same goes for curl. Curl is not supported by PHP by default. You need to open the loading extension= php_curl.dll in the configuration. Under Linux, remember to add the parameter -with-curl in ./configure when compiling PHP. To check whether the curl extension is turned on, you should be able to see it through phpinfo();.

1) Basic usage (general order of calls) curl_init: initialization, curl_setopt: Set parameter options curl_exec: Execute the current curl object curl_close: Close the current curl object

Example: Visit the PHP webpage that the code below is saved as, and we see the webpage of 126 mailboxes.

$curl = curl_init();
// Set the URL you need to crawl
curl_setopt($curl, CURLOPT_URL, 'http:// 126.com');
//Set header whether to display header information
//curl_setopt($curl, CURLOPT_HEADER, 1);
// Set the cURL parameters to require the results to be saved in a string or output to the screen.
//curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
// Run cURL and request the web page
$data = curl_exec($curl);
 // Close URL request
curl_close($curl);
// Display the obtained data
var_dump($data);

2) Send data via POST

﹤?php
$phoneNumber = '13912345678';
$message = 'This message was generated by curl and php';
$curlPost = 'pNUMBER=' . urlencode($phoneNumber) . '&MESSAGE= ' . urlencode($message) . '&SUBMIT=Send';
$ch = curl_init();
curl_setopt($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);
$data = curl_exec($ch );
curl_close($ch);
?﹥

3) Proxy server

﹤?php
$ch = curl_init();
curl_setopt($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 ');
$data = curl_exec($ch);
curl_close($ch);
?﹥

4) About SSL and Cookies Regarding SSL, which is the HTTPS protocol, you only need to change http:// in the CURLOPT_URL connection to https://. Of course, there is also a parameter called CURLOPT_SSL_VERIFYHOST that can be set to verify the site. Regarding cookies, you need to understand the following three parameters: CURLOPT_COOKIE, sets a cookie during the in-person session CURLOPT_COOKIEJAR, save a cookie when the session ends CURLOPT_COOKIEFILE, cookie file.

5) HTTP server authentication

﹤?php
$ch = curl_init();
curl_setopt($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]')
$data = curl_exec($ch) ;
curl_close($ch);
?﹥

Summary: Although several examples are attached later, the sequence is actually the same as the first one, except that the curl_setopt function will be different according to different situations. We also found that this function has many parameters and is very flexible.

The following parameters are used for this function: bool curl_setopt (int ch, string option, mixed value) The curl_setopt() function will set options for a CURL session. The option parameter is the setting you want, and value is the value given by this option.

The values ​​of the following options will be used as long integers (specified in the option parameter): * CURLOPT_INFILESIZE: When you upload a file to a remote site, this option tells PHP the size of the file you upload. * CURLOPT_VERBOSE: If you want CURL to report every unexpected event, set this option to a non-zero value. * CURLOPT_HEADER: If you want to include a header in the output, set this option to a non-zero value. * CURLOPT_NOPROGRESS: If you do not want PHP to display a progress bar for CURL transfers, set this option to a non-zero value. Note: PHP automatically sets this option to a non-zero value, you should only change this option for debugging purposes. * CURLOPT_NOBODY: If you do not want to include the body part in the output, set this option to a non-zero value. * CURLOPT_FAILONERROR: If you want PHP not to display when an error occurs (HTTP code return greater than or equal to 300), set this option to a non-zero value. The default behavior is to return a normal page and ignore the code. * CURLOPT_UPLOAD: If you want PHP to prepare for uploading, set this option to a non-zero value. * CURLOPT_POST: If you want PHP to do a regular HTTP POST, set this option to a non-zero value. This POST is of the ordinary application/x-www-from-urlencoded type, mostly used by HTML forms. * CURLOPT_FTPLISTONLY: Set this option to a non-zero value and PHP will list the FTP directory name list. * CURLOPT_FTPAPPEND: Set this option to a non-zero value and PHP will apply the remote file instead of overwriting it. * CURLOPT_NETRC: Set this option to a non-zero value and PHP will look in your ~./netrc file for the username and password of the remote site you want to connect to. * CURLOPT_FOLLOWLOCATION: Set this option to a non-zero header (like "Location: ") and the server will send it as part of the HTTP header (note that this is recursive, PHP will send a header like "Location: ") . * CURLOPT_PUT: Set this option to a non-zero value to upload a file using HTTP. To upload this file the CURLOPT_INFILE and CURLOPT_INFILESIZE options must be set. * CURLOPT_MUTE: Set this option to a non-zero value and PHP will be completely silent for the CURL function. * CURLOPT_TIMEOUT: Set a long integer as the maximum number of seconds. * CURLOPT_LOW_SPEED_LIMIT: Set a long integer to control how many bytes are transmitted. * CURLOPT_LOW_SPEED_TIME: Set a long integer to control how many seconds to transmit the number of bytes specified by CURLOPT_LOW_SPEED_LIMIT. * CURLOPT_RESUME_FROM: Pass a long parameter containing the byte offset address (the start form you want to transfer to). * CURLOPT_SSLVERSION: Pass a long parameter containing the SSL version. By default PHP will do its own hard work, in more security you have to set it manually. * CURLOPT_TIMECONDITION: Pass a long parameter to specify how to handle the CURLOPT_TIMEVALUE parameter. You can set this parameter to TIMECOND_IFMODSINCE or TIMECOND_ISUNMODSINCE. This is only for HTTP. * CURLOPT_TIMEVALUE: Pass a number of seconds from 1970-1-1 to now. This time will be used as the specified value by the CURLOPT_TIMEVALUE option, or by the default TIMECOND_IFMODSINCE.

The values ​​of the following options will be treated as strings: * CURLOPT_URL: This is the URL address you want to retrieve using PHP. You can also set this option during initialization with the curl_init() function. * CURLOPT_USERPWD: Pass a string in the form of [username]:[password] and use PHP to connect. * CURLOPT_PROXYUSERPWD: Pass a string in the format [username]:[password] to connect to the HTTP proxy. * CURLOPT_RANGE: Pass a range you want to specify. It should be in "X-Y" format, with X or Y being excluded. HTTP transfers also support several intervals, separated by commas (X-Y,N-M). * CURLOPT_POSTFIELDS: Pass a string containing all data as an HTTP "POST" operation. * CURLOPT_REFERER: A string containing a "referer" header in the HTTP request. * CURLOPT_USERAGENT: A string containing a "user-agent" header in the HTTP request. * CURLOPT_FTPPORT: Pass an IP address containing the IP address used by the ftp "POST" command. This POST instruction tells the remote server to connect to the IP address we specified. This string can be an IP address, a host name, a network interface name (under UNIX), or '-' (use the system default IP address). * CURLOPT_COOKIE: Pass a header connection containing an HTTP cookie. * CURLOPT_SSLCERT: Pass a string containing the certificate in PEM format. * CURLOPT_SSLCERTPASSWD: Pass a password containing the necessary password to use the CURLOPT_SSLCERT certificate. * CURLOPT_COOKIEFILE: Pass a string containing the name of the file containing cookie data. This cookie file can be in Netscape format, or it can be a stack of HTTP-style headers stored in the file. * CURLOPT_CUSTOMREQUEST: When making an HTTP request, pass a character to be used by GET or HEAD. Pass a string to be used instead of GET or HEAD when doing an HTTP request. This is useful for doing or another, more obscure, HTTP request. Note: Make sure your server supports Order not to do it yet. The following options require a file description (obtained using the fopen() function): * CURLOPT_FILE: This file will be the output file you place and transmit. The default is STDOUT. * CURLOPT_INFILE: This file is the input file you sent. * CURLOPT_WRITEHEADER: This file contains the header part of your output. * CURLOPT_STDERR: This file has errors written instead of stderr. An example of getting a page that requires login. The current method is to log in once every time, and people who need it will make improvements.

Commonly used functions: curl_close — close a curl session curl_copy_handle — Copy all contents and parameters of a curl connection resource curl_errno — Returns a numeric number containing error information for the current session curl_error — Returns a string containing error information for the current session curl_exec — execute a curl session curl_getinfo — Get information about a curl connection resource handle curl_init — Initialize a curl session curl_multi_add_handle — Add individual curl handle resources to a curl batch session curl_multi_close — Close a batch handle resource curl_multi_exec — parse a curl batch handle curl_multi_getcontent — Returns a text stream of fetched output curl_multi_info_read — Get the relevant transmission information of the currently parsed curl curl_multi_init — Initialize a curl batch handle resource curl_multi_remove_handle — Remove a handle resource in the curl batch handle resource curl_multi_select — Get all the sockets associated with the cURL extension, which can then be "selected" curl_setopt_array — Set session parameters for a curl as an array curl_setopt — Set session parameters for a curl curl_version — Get curl-related version information