PHP：正则表达式使用Lookbehind Assertions中的通配符替换单词

Question

I'm looking to create a PHP Regex script that can match and replace words within a string.

The regex needs to match only complete words, which I can easily accomplish with:

/\b(SEARCH_TERM)\b/

The problem I am having is that some of the strings contain html elements as such as <a> tags and <img> tags, where the href and src attributes may sometimes contain the to-be-replaced word within their path. If this word is replaced within these elements, then the link or image will no longer work.

Example, replace the word 'test' with 'SEARCH_TERM' for the following example string:

my test string <a href="http://www.google.com?q=my+test+string">link</a>

Would return:

my SEARCH_TERM string <a href="http://www.google.com?q=my+SEARCH_TERM+string">link</a>

Whereas I need it to ignore the href attribute text and return:

my SEARCH_TERM string <a href="http://www.google.com?q=my+test+string">link</a>

I've looked at using Regex's Lookbehind Assertions (As just below), but variable length wildcard characters are not allowed.

/(?<!(href|src)=.*)\b(SEARCH_TERM)\b/

Note: I specifically need to do this with Regex, and not a DOM parser.

Answer 1

As I mentioned you need to use an html parser.

But if you want it

/\btest\b(?=[^>]*(<|$))/s

Above regex would match only if there's < or end of string(not line) ahead somewhere without matching >

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NOTE

This would not work if your text itself contains >.

For example

 hello>world

Hence the reason you should use a parser