Regular expression in php to search url with a given pattern

Question

I want to search a given text for local URLs in link's href attributes, using regular expression. Currently, I have this regular expression:

'/href=["\']?([^"\'>]+)["\']?/'

Now, I'd like to add some more filtering: Only get those links, which start like this:

XXXX-XX-XX

Where X is a number. This should match this: 2015-05-15/ , 2015-05-15_03_21_32/ and also 2014-12-21 (any date set by me).

Answer 1

You can use the following regex:

href=["']?(\d{4}(?:[-_]\d{2})+)["']?

PHP: $re = "#href=[\\"']?(\\d{4}(?:[-_]\\d{2})+)[\\"']?#";

Explanation:

href=["']? - matches href= and an optional single or double quote
(\\d{4}(?:[-_]\\d{2})+) - a capturing group around the href attribute value
- \\d{4} - Exactly 4 digits
- (?:[-_]\\d{2})+ - 1 or more groups of - / _ + 2-digit numbers
["']? - matches an optional single or double quote