Question

I am developing an application using PHP but I am new to regular expressions, I could not find a solution to my problem. I want to replace all occurences of #word with a link, i have written a preg_match for this:

$text=preg_replace('~#([\p{L}|\p{N}]+)~u', '<a href="/?aranan=$1">#$1</a>', $text);

The problem is, this regular expression also matches the html character codes like

'

and gives corrupt output. I need to exclude the words starting with &# but i do not know how to do that using regular expressions.

Thanks for your help.

Answer 1

'~(?<!&)#([\p{L}|\p{N}]+)~u'

That’s a negative lookbehind assertion: http://www.php.net/manual/en/regexp.reference.assertions.php

Matches # only if not preceded by &