Re: fortran/4885: BACKSPACE example that doesn't work as of gcc/g77-3.0.x

[Youngjean Jung <yjjung@newton.me.berkeley.edu>]

The following reply was made to PR fortran/4885; it has been noted by GNATS.

From: Youngjean Jung <yjjung@newton.me.berkeley.edu>
To: Toon Moene <toon@moene.indiv.nluug.nl>
Cc: Youngjean Jung <yjjung@newton.me.berkeley.edu>,
        Tim Prince <tprince@computer.org>, gcc-gnats@gcc.gnu.org
Subject: Re: fortran/4885: BACKSPACE example that doesn't work as of  gcc/g77-3.0.x
Date: Fri, 16 Nov 2001 16:07:41 -0800

 Dear Mr. Toon Moene and Mr. Tim Prince :
 
 Thank you so much for your kind attention. It really helps me to resolve 
 the problem, even though I feel that using backspace twice seems kind of 
 silly. Anyhow, I can resolve the problem. You are the best and kindest 
 programmers I ever met in internet. I have been using FEAP ( Finite 
 Element Analysis Program) developed by Berkeley and Stanford faculties, 
 which is not yet comercialized for research purpose. Even though Fortran 
 is getting old language, most FEM and FDM in solid and fluid mechanics 
 are still using Fortran. In the sense, the necessity of g77 doesn't 
 vanish at all.
 Many people like me still get the benefit of your effort.
 
 I appreciate you for your help again.
 
 Cheers,
 
 Youngjean Jung
 Ph. D. Candidate
 Computational Mechanics Lab
 Deptment of Mechanical Engineering
 University of California, Berkeley
 
 Toon Moene wrote:
 
 >Youngjean Jung wrote:
 >
 >>I conducted many tests on the Endfile, Backspace commands. They don't
 >>work in the following senses:
 >>
 >>1) Endfile command writes meaningless letters on the data file.
 >>2) Endfile, Backspace combination doesn't make a 'backspace job'.
 >>
 >
 >>      program test
 >>c
 >>      implicit none
 >>      integer  i,k
 >>c
 >>      do i=1,10
 >>        open(1,file='s2.dat',status='unknown',access='sequential')
 >>        do k=10,20
 >>           write(1,*) i,k
 >>           endfile 1
 >>           backspace 1
 >>        end do
 >>        close(1)
 >>      end do
 >>c
 >>      end
 >>
 >
 >Hmmm, I get the same s2.dat as you get (Debian GNU/Linux 2.2,
 >gcc/g77-3.0.2):
 >
 >toon@laptop:~/g77-bugs$ cat s2.dat
 > 10 10
 > 10 11
 > 10 12
 > 10 13
 > 10 14
 > 10 15
 > 10 16
 > 10 17
 > 10 18
 > 10 19
 > 10 20
 >
 >This seems to be in accordance with the Standard:
 >
 >12.10.4.1 BACKSPACE Statement.
 >
 >Execution of a BACKSPACE statement causes the file connected to the
 >specified unit to be positioned before the preceding record. If there is
 >no preceding record, the position of the file is not changed. Note that
 >if the preceding record is an endfile record, the file becomes
 >positioned before the endfile record. 
 >
 >In other words, your backspace only backspaces over the endfile record
 >(as per the standard).  If you want to backspace over the record you
 >just wrote, you have to backspace twice.
 >
 >[Tim - does this mean I can close fortran/4885 ?  Thanks]
 >