mixed File_Passwd_Custom::modUser ( 
    string $user
     , array $properties = array()
   )
You shouldn't modify the password of the user with this method, use File_Passwd_Custom::changePasswd() instead.
You should use this method only if the 'name map' is used, too.
$user
     the user to modify
$properties
     an associative array of properties to modify
Returns TRUE on success, PEAR_Error on failure.
| Error Code | Summary | 
|---|---|
| FILE_PASSWD_E_EXISTS_NOT | user doesn't exists | 
| FILE_PASSWD_E_INVALID_CHARS | any of the extra properties contains the delimiter | 
This function can not be called statically.