Question

Currently I’m using a small search and replace snippet for one of my WordPress sites:

if ( ! function_exists( 'cor_remove_personal_options' ) ) {
  function cor_remove_personal_options( $subject ) {
    $pattern = '#<h3>Personal Options</h3>.+?/table>#s';
    $subject = preg_replace( $pattern, '', $subject, 1 );
    return $subject;
  }

  function cor_profile_subject_start() {
    ob_start( 'cor_remove_personal_options' );
  }

  function cor_profile_subject_end() {
    ob_end_flush();
  }
}
add_action( 'admin_head-profile.php', 'cor_profile_subject_start' );
add_action( 'admin_footer-profile.php', 'cor_profile_subject_end' );

Being relatively new with preg_replace I was wondering about the exact functionality of the opening and closing number signs # #s.

I was wondering if someone could perhaps explain this to me?

Answer 1

You can use / as opening and closing characters or #. If you use #, then the slash will not be taken as a special character, so this will be valid too escaping the slash character:

'/<h3>Personal Options<\/h3>.+?\/table>/s'

/s or #s means a modifier, telling to PHP that any dot in the regular expression will be evaluated as any character, including new lines.