Php converts the url address to the complete a tag link code (php adds a tag for the url address)

This article describes how to add a tag for a url address in php. for details, refer to the following content:

The code is as follows:
Http://baidu.com this is the first A tag,
Growth footprint-focusing on Internet development is the second A tag.
Http://www.bitsCN.com this is the first URL to be extracted,
Http://blog.baidu.com this is the second URL address to be extracted '.
This is an IMG tag

For example, the URL automatically extracted from Weibo is a hyperlink address. That is, extract the content and add the tag, and convert it into A real hyperlink. I searched the internet for a long time and did not find a feasible solution. Most of them are simply extracted URLs (the addresses in tags A and IMG are also extracted and replaced) and cannot meet the above requirements. The regular expression does not find any way to filter out the tag during extraction. So I switched my mind to "saving the nation through the curve ". That is, replace all the and IMG tags with A unified regex, and then extract the URL address and replace it with A hyperlink, finally, replace the unified Mark restoration with the previous A and IMG labels.

The code is as follows:
Function linkAdd ($ content ){
// Extract and replace all A Tags (unified tag <{link}>)
Preg_match_all ('/.*? /I ', $ content, $ linkList );
$ LinkList = $ linkList [0];
$ Str = preg_replace ('/.*? /I ',' <{link}> ', $ content );

// Extract and replace all IMG tags (unified tag <{img}>)
Preg_match_all ('/] +>/im', $ content, $ imgList );
$ ImgList = $ imgList [0];
$ Str = preg_replace ('/] +>/im', '<{img}>', $ str );

// Extract and replace the standard URL address
$ Str = preg_replace ('(f | ht) {1} tp: //) [-a-zA-Z0-9 @: % _/+ .~ #? & // =] +) ',' \ 0', $ str );

// Restore the uniform A tag to the original A tag
$ ArrLen = count ($ linkList );
For ($ I = 0; $ I <$ arrLen; $ I ++ ){
$ Str = preg_replace ('/<{link}>/', $ linkList [$ I], $ str, 1 );
}

// Restore the IMG tag to the original IMG tag
$ ArrLen2 = count ($ imgList );
For ($ I = 0; $ I <$ arrLen2; $ I ++ ){
$ Str = preg_replace ('/<{img}>/', $ imgList [$ I], $ str, 1 );
}

Return $ str;
}

$ Content ='
Http://baidu.com this is the first A tag,
Growth footprint-focusing on Internet development is the second A tag.
Http://www.bitsCN.com this is the first URL to be extracted,
Http://blog.baidu.com this is the second URL to be extracted.
, This is an IMG tag ';
Echo linkAdd ($ content );

The returned content is:

The code is as follows:
Http://baidu.com is the first A tag, growth footprint-focus on the development of the Internet this is the second A tag. Http://www.bitsCN.com this is the first URL address to be extracted, http://blog.baidu.com this is the second URL address to be extracted.
This is an IMG tag

That is, what we want.

Example 2,
The code is as follows:
/**
* The PHP version is modified based on the Silva code
* Convert the URL address to the complete A tag link code
*/

Function replace_URLtolink ($ text ){
// Grab anything that looks like a URL...
$ Urls = array ();

// Build the patterns
$ Scheme = '(https? : // | Ftps? ://)? ';
$ Www = '([w] + .)';
$ Ip = '(d {1, 3}. d {1, 3}. d {1, 3}. d {1, 3 })';
$ Name = '([w0-9] + )';
$ Tld = '(w {2, 4 })';
$ Port = '(: [0-9] + )? ';
$ The_rest = '(/? ([W #! :.? + = & % @! -/] + ))? ';
$ Pattern = $ scheme. '('. $ ip. $ port. '|'. $ www. $ name. $ tld. $ port. ')'. $ the_rest;
$ Pattern = '/'. $ pattern. '/is ';

// Get the URLs
$ C = preg_match_all ($ pattern, $ text, $ m );

If ($ c ){
$ Urls = $ m [0];
}

// Replace all the URLs
If (! Empty ($ urls )){
Foreach ($ urls as $ url ){
$ Pos = strpos ('http: // ', $ url );

If ($ pos & $ pos! = 0) |! $ Pos ){
$ Fullurl = 'http: // '. $ url;
} Else {
$ Fullurl = $ url;
}

$ Link = ''. $ url .'';

$ Text = str_replace ($ url, $ link, $ text );
}
}

Return $ text;
}