preg_replace: regex does not work

Question

I am trying to remove a part with social links from an RSS feed with a RegEx like this:

preg_replace("/<p>.*?facebook.*?</p>/", "", $rss_string);

where $rss_string could be eg.

<description>important_content&lt;p&gt;facebook_rubbish_here&lt;/p&gt;</description>

At first it sais invalid modifier 'p'. Then I changed /p to \/p which caused it to run, but it does not find anything... What am I doing wrong? Am I not escaping something which I should?

Thank you!

Answer 1

As I said, I then escaped the /p but it still did not work. I have just found out that the solution was that in preg_replace, the DOT does not match the newline character so I needed to use the 's' option.

Answer 2

It is because you're using regex delimiter slash and your regex also contains slash. Either escape the forward slash or better use an alternative regex delimiter.

preg_replace('~<p>.*?facebook.*?</p>~', "", $rss_string);