Article ID: 112333
Article Last Modified on 10/17/2003
APPLIES TO
- Microsoft FORTRAN PowerStation 1.0 Standard Edition
- Microsoft Fortran PowerStation 1.0a for MS-DOS
- Microsoft FORTRAN PowerStation 32
This article was previously published under Q112333
SYMPTOMS
Run-time error F6101 or F6103 (invalid INTEGER or invalid REAL) may be generated on reading from the last record in a file using Microsoft FORTRAN PowerStation.
CAUSE
The CTRL+Z character is not treated as the true end-of-file marker in MS-DOS or Windows. This character is interpreted as a nonstandard character by FORTRAN PowerStation in many circumstances.
RESOLUTION
To resolve this problem, remove the CTRL+Z character from the end of data files. The function NO_CTRLZ provided below may be used to do this for any file with or without the CTRL+Z character.
STATUS
Microsoft has confirmed this to be a problem in Microsoft FORTRAN PowerStation 32 version 1.0 and 1.0a for MS-DOS and version 1.0 for Windows NT. This problem was corrected in FORTRAN PowerStation 32, version 4.0.
MORE INFORMATION
To demonstrate the problem:
- Build MAKEDATA.FOR and READDATA.FOR (no options are needed).
- Run MAKEDATA to create a data file ending in a CTRL+Z character.
- Run READDATA to generate the error:
To fix the data file, build STRIP:
FL32 strip.for no_ctrlz.for
Run STRIP (which uses NO_CTRLZ to remove the CTRL+Z):
STRIP z-test.dat
- Run READDATA again (no error will be generated).
Sample Code MAKEDATA.FOR
C Compile options needed: None open(10, file='z-test.dat',form='BINARY') write(10) '1234', char(26) end
Sample Code READDATA.FOR
C Compile options needed: None open(10,file='z-test.dat') do i=1,20 read(10,*,end=9) k print *, k enddo 9 end
Sample Code STRIP.FOR
C Compile options needed: None C To build it use: "FL32 STRIP.FOR NO_CTRLZ.FOR" include 'flib.fi' include 'flib.fd' character *40 filename integer*2 i if (NARGS() .gt. 1) then call getarg(1, filename, i) i = no_ctrlz(filename) if (i .ne. 0) then print *, 'Could not open the file: ', filename end if end if end
Sample Code NO_CTRLZ.FOR
C Compile options needed: None c NO_CTRLZ removes the last character in a file if it is CTRL+Z c c Returns 1 if there are problems, otherwise 0. c integer function no_ctrlz(filename) character c, filename*(*) logical exist inquire(file=filename(:len_trim(filename)),EXIST=exist) if (.not. exist) then no_ctrlz = 1 return end if open(10,file=filename(:len_trim(filename)),access='APPEND', + form='BINARY',recl=1) c Check if the last character is CTRL+Z backspace(10) read(10) c if (ichar(c) .ne. 26) then no_ctrlz = 0 !No error, just don't need to do anything return end if c Backup, and then rewrite the next to last character to reset c the true end-of-file marker. backspace(10) backspace(10) read(10) c backspace(10) write(10) c close(10) no_ctrlz = 0 !COMPLETED SUCCESSFULLY end
Additional Reference Words: 1.00 ctrl-z
Keywords: kbbug kbfix kblangfortran KB112333