I recently encountered a problem trying to capture multiple instances of named subpatterns from filenames.
Therefore, I came up with this function.

The function allows you to pass through flags (in this version it applies to all expressions tested), and generates an array of search results.

Enjoy!

<?php

/**
 * Allows multiple expressions to be tested on one string.
 * This will return a boolean, however you may want to alter this.
 *
 * @author William Jaspers, IV <wjaspers4@gmail.com>
 * @created 2009-02-27 17:00:00 +6:00:00 GMT
 * @access public
 *
 * @param array $patterns An array of expressions to be tested.
 * @param String $subject The data to test.
 * @param array $findings Optional argument to store our results.
 * @param mixed $flags Pass-thru argument to allow normal flags to apply to all tested expressions.
 * @param array $errors A storage bin for errors
 *
 * @returns bool Whether or not errors occurred.
 */
function preg_match_multiple( 
  array $patterns=array(), 
  $subject=null,
  &$findings=array(),
  $flags=false,
  &$errors=array()
) {
  foreach( $patterns as $name => $pattern )
  {
    if( 1 <= preg_match_all( $pattern, $subject, $found, $flags ) )
    {
      $findings[$name] = $found;
    } else 
    {
      if( PREG_NO_ERROR !== ( $code = preg_last_error() ))
      {
        $errors[$name] = $code;
      } else $findings[$name] = array();
    }
  }
  return (0===sizeof($errors));
}
?>