FilePos function

  DECLARATION:  FilePos(var F);

      PURPOSE:  Returns the current file position of a file.

         UNIT:  System

  RESULT TYPE:  LongInt

      REMARKS:  Where F is a file variable, FilePos returns a zero
                to indicate the beginning of a file.  If the current
                position is at the end of file, EOF(F) = TRUE, then
                FilePos(F) is equal to FileSize(F).

                NOTE: With {$I-}, errors are returned through IOResult

 RESTRICTIONS:  Cannot be used on Text files.
                File must be open.

  DIFFERENCES:  The result type in v3.0 was an integer.