FIX: EOF and BACKSPACE Cause GP Fault When the Unit Isn't Open

MS-DOS     | WINDOWS NT

The information in this article applies to:

• Microsoft FORTRAN PowerStation for MS-DOS, versions 1.0 and 1.0a
• Microsoft FORTRAN PowerStation 32 for Windows NT, version 1.0

SYMPTOMS

Passing an unopened unit number to the EOF intrinsic function or the BACKSPACE command generates the run-time error:

FORTRAN PowerStation for MS-DOS

   DOSXMSF : fatal error DX1020: unhandled exception: General
             protection fault;

FORTRAN PowerStation 32 for Windows NT

   Application Error

   The instruction at "0x0001316e" referenced memory at 0x00000000". The
   memory could not be "read".

CAUSE

The following run-time error should be produced:

   run-time error F6420: EOF()
   - unknown unit number

RESOLUTION

Only use the EOF function and BACKSPACE command on units that are currently open.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was fixed in FORTRAN PowerStation, version 4.0.

MORE INFORMATION

The following sample code generates a DX1020 error (GPF) when run:

Sample Code

C Compile options: None

      logical l
      open(2,file='test.out')
      l = EOF(1)
      end