PHP page capture method summary

When doing some Internet applications, you often need to capture most of the web files. In general, PHP is used to simulate browser access and access the URL address through HTTP requests, then we can get the HTML source code or other format data, and then process and format the data, and output the data to the terminal or other interfaces as agreed in advance.

I. Main Methods for capturing pages in PHP:

1. File () function

2. file_get_contents () function

3. fopen ()-> fread ()-> fclose () Mode

4. Curl Method

5. fsockopen () function Socket mode

6. Use plug-ins (such as: http://sourceforge.net/projects/snoopy)

Ii. Main Methods for parsing HTML or XML code in PHP:

1. Regular Expression

2. php domdocument object

3. Plug-ins (for example, PHP simple HTML Dom parser)

If you are familiar with the above content, you can see the following content ......

PHP crawling page

1. File () function

Copy the Code as follows:

<? PHP

$ Url = 'HTTP: // t.qq.com ';

$ Lines_array = file ($ URL );

$ Lines_string = implode ('', $ lines_array );

Echo htmlspecialchars ($ lines_string );

?>

2. file_get_contents () function

Use file_get_contents and fopen to enable allow_url_fopen. Method: Edit PHP. ini and set allow_url_fopen = on. When allow_url_fopen is disabled, neither fopen nor file_get_contents can open remote files.

Copy the Code as follows:

<? PHP

$ Url = 'HTTP: // t.qq.com ';

$ Lines_string = file_get_contents ($ URL );

Echo htmlspecialchars ($ lines_string );

?>

3. fopen ()-> fread ()-> fclose () Mode

Copy the Code as follows:

<? PHP

$ Url = 'HTTP: // t.qq.com ';

$ Handle = fopen ($ URL, "rb ");

$ Lines_string = "";

Do {

$ DATA = fread ($ handle, 1024 );

If (strlen ($ data) = 0) {break ;}

$ Lines_string. = $ data;

} While (true );

Fclose ($ handle );

Echo htmlspecialchars ($ lines_string );

?>

4. Curl Method

Use curl to enable curl. Method: Modify PHP. ini in windows, remove the semicolon before extension = php_curl.dll, and copy ssleay32.dll and libeay32.dll to c: \ windows \ system32. Install curl extension in Linux.

Copy the Code as follows:

<? PHP

$ Url = 'HTTP: // t.qq.com ';

$ CH = curl_init ();

$ Timeout = 5;

Curl_setopt ($ ch, curlopt_url, $ URL );

Curl_setopt ($ ch, curlopt_returntransfer, 1 );

Curl_setopt ($ ch, curlopt_connecttimeout, $ timeout );

$ Lines_string = curl_exec ($ ch );

Curl_close ($ ch );

Echo htmlspecialchars ($ lines_string );

?>

5. fsockopen () function Socket mode

Whether the socket mode can be correctly executed depends on the server settings. You can use phpinfo to check which communication protocols are enabled on the server. For example, my local PHP socket does not enable HTTP, you can only use UDP for testing.

Copy the Code as follows:

<? PHP

$ Fp = fsockopen ("UDP: // 127.0.0.1", 13, $ errno, $ errstr );

If (! $ FP ){

Echo "error: $ errno-$ errstr <br/> \ n ";

} Else {

Fwrite ($ FP, "\ n ");

Echo fread ($ FP, 26 );

Fclose ($ FP );

}

?>

6. Plug-ins

There should be a lot of plug-ins on the Internet, and Snoopy plug-ins are found on the Internet. If you are interested, you can study them.

PHP parses XML (HTML)

1. Regular Expression:

Copy the Code as follows:

<? PHP

$ Url = 'HTTP: // t.qq.com ';

$ Lines_string = file_get_contents ($ URL );

Eregi ('<title> (. *) </title>', $ lines_string, $ title );

Echo htmlspecialchars ($ title [0]);

?>

2. php domdocument () object

If the remote HTML or XML file has a syntax error, PHP will report an error when parsing the Dom.

Copy the Code as follows:

<? PHP

$ Url = 'HTTP: // www.136web.cn ';

$ Html = new domdocument ();

$ HTML-> loadhtmlfile ($ URL );

$ Title = $ HTML-> getelementsbytagname ('title ');

Echo $ title-> item (0)-> nodevalue;

?>

3. Plug-ins

This article takes PHP simple HTML Dom parser as an example to give a brief introduction. The simple_html_dom syntax is similar to jquery, which allows PHP to operate the Dom, just as simple as using jquery to operate the Dom.

Copy the Code as follows:

<? PHP

$ Url = 'HTTP: // t.qq.com ';

Include_once ('../simplehtmldom/simple_html_dom.php ');

$ Html = file_get_html ($ URL );

$ Title = $ HTML-> Find ('title ');

Echo $ title [0]-> plaintext;

?>