$re = '/.*(DIMENSIONS: \|)/m';
$str = '1. DIMENSIONS: | ORIGIN: | Position corrected and IL (0) was changed based on RPS: 3482 -230
2. DIMENSIONS: 2 x 1350 RCP | ORIGIN: PCD13180 | Position corrected and IL (0) was changed based on RPS: 1390 -20800/1350RCP
3. DIMENSIONS: 3 x 375 RCP | ORIGIN:
4. DIMENSIONS: | ORIGIN:
5. Review attribution | DIMENSIONS: | ORIGIN:';
preg_match_all($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