I/O Checking                       {$I+}                             pp 314

 Default:   Active

 Scope:     Local

 Active:    {$I+}  All I/O operations are checked for errors.

 Inactive:  {$I-}  Programmer uses IOResult function for checking.


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 Notes:     When active, I/O errors cause the program to terminate and a
            message to be issued.

            When passive, no run time checks are performed.  An I/O error
            does not cause program termination, but suspends any further
            I/O until the standard function IOResult is called.  Once done,
            the error condition is reset, and I/O may continue.

            An IOResult return code of zero indicates successful complettion.
            Any other code indicates an error has occurred.

            The I directive allows the programmer to safely handle user
            filename input errors, or file errors without halting the
            program execution.