Question

I need to try and strip out lines in a text file that match a pattern something like this:

anything SEARCHTEXT;anything;anything

where SEARCHTEXT will always be a static value and each line ends with a line break. Any chance someone could help with the regext for this please? Or give me some ideas on where to start (been to many years since I looked at regex).

I am planning on using PHP’s preg_replace() for this.

Thanks.

Answer 1

This solution removes all lines in $text which contain the sub-string SEARCHTEXT:

$text = preg_replace('/^.*?SEARCHTEXT.*\n?/m', '', $text);

My benchmark tests indicate that this solution is more than 10 times faster than '/\n?.*SEARCHTEXT.*$/m' (and this one correctly handles the case where the first line matches and the second one doesn’t).