| 1.20.x install.inc | backdrop_install_mkdir($file, $mask, $message = TRUE) | 
Creates a directory with the specified permissions.
Parameters
$file: The name of the directory to create;
$mask: The permissions of the directory to create.
$message: (optional) Whether to output messages. Defaults to TRUE.
Return value
TRUE/FALSE whether or not the directory was successfully created.:
File
- includes/install.inc, line 1223 
- API functions for installing modules and themes.
Code
function backdrop_install_mkdir($file, $mask, $message = TRUE) {
  $mod = 0;
  $masks = array(FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);
  foreach ($masks as $m) {
    if ($mask & $m) {
      switch ($m) {
        case FILE_READABLE:
          $mod |= 0444;
          break;
        case FILE_WRITABLE:
          $mod |= 0222;
          break;
        case FILE_EXECUTABLE:
          $mod |= 0111;
          break;
      }
    }
  }
  if (@backdrop_mkdir($file, $mod)) {
    return TRUE;
  }
  else {
    return FALSE;
  }
}