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  Returns
 
    Word    Status of the most recent I/O operation
 
  Description
 
    The IOResult function returns the error code from the most recent
    input or output operation. IOResult returns 0 if the operation was
    successful.
 
    The code returned is a run-time error number. The error number
    matches one of the MS-DOS(R) extended error codes for an MS-DOS
    Interrupt 21H function call. Consult a DOS reference for a list of
    these errors.
 
    I/O errors are trapped only if I/O checking is turned off. The
    Input/Output-Checking directive, {$I-}, turns I/O checking off.
 
    With I/O checking turned off, generation of run-time errors is
    disabled; thus IOResult must be called after every I/O operation.
    InOutRes, defined in the System unit, holds the error code.
    IOResult resets InOutRes when retrieving the code. A repeat
    call to IOResult, therefore, is invalid.
 
    If I/O checking is turned off and IOResult is not called after an
    I/O operation, subsequent calls to certain I/O operations will be
    ignored. The following routines require IOResult to be called if
    {$I-} is set and a previous I/O error has occurred:
 
      BlockRead   ║  FileSize  ║  SeekEof
      BlockWrite  ║  Flush     ║  SeekEoln
      Close       ║  Read      ║  Write
      Eof         ║  Readln    ║  Writeln
      Eoln        ║  Seek      ║