php - How to make dot match newline characters using regular expressions

Question

I have a string that contains normal characters, white charsets and newline characters between and . This regular expression doesn't work: /<div>(.*)</div>. It is because .* doesn't match newline characters. My question is, how to do this?

question from:https://stackoverflow.com/questions/1985941/how-to-make-dot-match-newline-characters-using-regular-expressions

Answer 1

You need to use the DOTALL modifier.

'/<div>(.*)</div>/s'

This might not give you exactly what you want because you are greedy matching. You might instead try a non-greedy match:

'/<div>(.*?)</div>/s'

You could also solve this by matching everything except '<' if there aren't other tags:

'/<div>([^<]*)</div>/'

Another observation is that you don't need to use / as your regular expression delimiters. Using another character means that you don't have to escape the / in </div>, improving readability. This applies to all the above regular expressions. Here's it would look if you use '#' instead of '/':

'#<div>([^<]*)</div>#'

However all these solutions can fail due to nested divs, extra whitespace, HTML comments and various other things. HTML is too complicated to parse with Regex, so you should consider using an HTML parser instead.