$re = '/\/books\/[^\/]/';
$str = 'stuffbefore/books/the-tel-aviv-farmers-market/?fb_action_ids=10201758621202245&fb_action_types=og.likes';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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