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 12:56:07 -0800

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 Dear Mr. Toon Moene :
 
 Don't you have any gabage letters in s2.dat?
 
 Youngjean
 
 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]
 >
 
 
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 IDEwIDEwCgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 AAAAAAAAIDEwIDExCiAxMCAxMgogMTAgMTMKIDEwIDE0CiAxMCAxNQogMTAgMTYKIDEwIDE3
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