preg_replace to exclude PHP

Question

Im using preg_replace to replace keywords in text with a href tag, my regex is working awesome, right now my code is:

$newstring2 = preg_replace(\"/\\p{L}*?\         


        

Answer 1

If it must be done with regex I think PCRE verbs are your best option. Exclude all links then search for the term with word boundaries.

<a[\S\s]+?<\/a>(*SKIP)(*FAIL)|\bTERM\b

Demo: https://regex101.com/r/KlE1kc/1/

an example of a flaw with this though is if the a ever had a </a> in it. e.g. onclick='write("</a>")' a parser is really the best approach. There are a lot of gotchas with HTML and regexs.

Answer 2

How about this with negative lookahead. Regex

Explanation: capture all the keyword that is called text and replace with it some link but don't capture those keywords that have </a> after it.

$re = '/(text)(?!<\/a>)/m';
$str = 'this is sample text about something what is text.

this is sample <a href=\'somelink.php\'>text</a> about something what is <a href=\'somelink.php\'>text</a>.';
$subst = '<a href=\'somelink.php\'>$1</a>';

$result = preg_replace($re, $subst, $str);

echo $result;

Output:

this is sample <a href='somelink.php'>text</a> about something what is <a href='somelink.php'>text</a>. 

this is sample <a href='somelink.php'>text</a> about something what is <a href='somelink.php'>text</a>.

DEMO: https://3v4l.org/DVTB1