$re = '/.*Page/';
$str = 'A_File1_Page1
A_File1_Page2
A_File2_Page1
A_File2_Page2
A_File2_Page3
B_File1_Page1
B_File1_Page2
B_File1_Page3
B_File2_Page1
B_File2_Page2
B_File2_Page3
B_File2_Page4
C_File1_Page1
C_File1_Page2
C_File1_Page3
C_File1_Page4
C_File1_Page5';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php