- print_r: documentation ( source)
- preg_match_all: documentation ( source)
<?php
$subject = '..some code here..
<a href=\"members/username1.12345/\" class=\"username bigs\" title=\"\">Username 1</a>
..some code here..
..some code here..
<a href=\"members/username2.55334/\" class=\"username bigs\" title=\"\">Username 2</a>
..some code here..
..some code here..
<a href=\"members/username3.23455/\" class=\"username bigs\" title=\"\">Username 3</a>
..some code here..
..some code here..
<a href=\"members/username4.45545/\" class=\"username bigs\" title=\"\">Username 4</a>
..some code here..';
$pattern = '@<a href="members/.+/" class="username bigs" title="">(.+)</a>@U';
$result = preg_match_all($pattern, $subject, $subpattern);
echo '<pre>'.print_r($subpattern, TRUE).'</pre>';