Primary Method and Description Arguments DataError This method sends a DATA_ERR string back to the Application Management Toolkit and sets an internal variable  $err_code  to  1, which is used by the  UaTkMain  method and the _send_acknowledgment( )  internal function to detect error conditions. When this occurs, processing continues, but no ACK string is sent back to the Application Management Toolkit. DATA_ERR is used to indicate conditions such as   user does not exist   by the  EXISTS  command. See also:  _send_acknowledgment( ),  UaTkMain $msg  - string IOError This method sends an IO_ERR string back to the Application Management Toolkit and sets an internal variable  $err_code  to  2, which is used by the  UaTkMain  method and the _send_acknowledgment( )  internal function to detect error conditions. When this occurs, processing continues, but no ACK string is sent back to the Application Management Toolkit. An IO_ERR string should be used when the application cannot make sense out of the data sent; for example, it might be sent if a DISTRIBUTE  command was issued with a set of attributes, then the  MODIFY  handler detected an attribute not in the distribute list. The message is logged to the error file or logfile. See also:  _send_acknowledgment( ),  UaTkMain $msg  - string FatalError This method sends a FATAL_ERR string back to the Application Management Toolkit and sets an internal variable  $err_code  to  9, which when detected by the  UaTkMain  method causes it to exit by returning a  -1. This does prevent acknowledgments and is not immediate. The message is logged to the error file or logfile. See also:  _send_acknowledgment( ),  UaTkMain,  Exit $msg  - string Developing Your Application in Perl 65 Tivoli®  SecureWay Application Management Toolkit Guide