preg-replace, xhtml strict, php, & ampersand error

Question

Wondering if there is a handy preg_replace or similar function that will change all my & to & but will not change & to &amp; (won't change an & that is already in the proper format).

I am having problem displaying a page that has (user submitted) & and I wanted to change them (from a block of text fetched from mysql) just before displaying in the page.

Help will be appreciated. Cheers.

PS: I thought of using a str_replace with an & with space on either side, but then I stopped thinking about typos like Bob &Jenny in lieu of Bob & Jenny (since user submitted).

It sounds like you're double/partially encoding it. You should figure out why you have encoded and unencoded data together and fix that issue. — Richard Marskell - Drackir, Apr 19 '11 at 20:03
I haven't encoded anything @Drackir, it's just that in xhtml strict, an user submitted sentence having something like `Bob & Jenny` in it will hinder display of the page. — Jeremy Roy, Apr 19 '11 at 20:06
Where are you getting the extra `&`s from then? Is the user submitting them? I'm just confused as to why your data would ALREADY have `&` in it if you haven't encoded it yet. — Richard Marskell - Drackir, Apr 19 '11 at 20:09
No that part I mentioned just as a cautionary measure. I don't have & there. Thanks anyway. Best. — Jeremy Roy, Apr 19 '11 at 20:14
If it's not a problem then why not just use the [htmlentities function](http://php.net/manual/en/function.htmlentities.php)? — Richard Marskell - Drackir, Apr 19 '11 at 20:23

score 1 · Answer 1 · answered Apr 19 '11 at 20:09

1

You can use an ?! assertion for that:

$html = preg_replace('/&(?!#?\w+;)/', "&amp;", $html);
              # or just (?!amp;)

This also skips existing & and other < or { entities. But it's certainly not faultless.

answered Apr 19 '11 at 20:09

mario

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preg-replace, xhtml strict, php, & ampersand error

1 Answers1