具有两个连续（相同或不相同）匹配的正则表达式

Question

I've written this regex for a PHP regex function:

\[\[.*?\]\]

This matches words or phrases between double square brackets. What I'm trying to find now is a regexp that match two or more consecutive (identical or not) matches. I've tried with

(\[\[.*?\]\]){2,}

and with this workaround: Regular Expression For Consecutive Duplicate Words. However, none of them worked. Does anyone has a better idea?

What I'm trying to match is, for example, [one][two][three]. The first part of the regexp will match [one] and I'm trying to get the entire phrase [one][two][three].

Thanks!

Answer 1

If you remove 1 bracket from both sides of your second pattern, it will already work. See (\[.*?\]){2,}.

A more elegant solution is (?:\[[^][]*]){2,}. Here, \[ matches a [, [^][]* will match zero or more characters other than ] and [ and ] will match a closing literal ].

If you want to capture the first [one] into Group 1, use (\[[^][]*])(?1)+. Here, (?1) re-uses Group 1 subpattern (i.e. \[[^][]*]).

Here is a PHP demo:

$re = '~(?:\[[^][]*]){2,}~'; 
$str = "[one][two][three]"; 
preg_match($re, $str, $matches);
print_r($matches[0]); // => [one][two][three]