preg_replace backreference date function

Question

PHP 5.2.15

I am trying to replace {date[F]} with the date function.

I have the pattern which works great.

preg_replace('/({date\[(.*?)\]})/', date(${2}), $subject);

I have tried preg_replace_callback but it doesn't seem to work even when I use create_function()

I get mostly undefined errors on my methods tried.

Answer 1

You do need the /e modifier. And the replacement expression must be a string:

= preg_replace('/(\{date\[(.*?)\]})/e', 'date("$2")', $subject);

Note that you also forgot to escape the first { curly brace.

See the manual examples for preg_replace#105490. Or how preg_replace_callback callbacks must unpack the match parameter (which sounds like your original issue).