Remarks 

The $I switch directive enables or disables the automatic code generation that checks the result of a call to an I/O procedure. I/O procedures are described in the Delphi Language Guide. If an I/O procedure returns a nonzero I/O result when this switch is on, an EInOutError exception is raised (or the program is terminated if exception handling is not enabled). When this switch is off, you must check for I/O errors by calling IOResult.