Article View: net.lang.f77
Article #290Re: Minor I/O bug (and my favorite f77 I/O bug)
From: Daniel R. Levy
Date: Sat, 04 Jan 1986 03:59
Date: Sat, 04 Jan 1986 03:59
56 lines
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2573 bytes
In article <115@sdcsmb.UUCP>, pmontgom@sdcsmb.UUCP (Peter Montgomery) writes:
>In article <247@xanth.UUCP> tadguy@xanth.UUCP (Tad Guy) writes:
>>>The f77 compiler complains of a syntax error at the first line of the
>>>following program (4.2bsd on VAX, v2.0 on SUN):
>>> write(6,10) (-1)
>>>10 format(i2)
>>> end
>>I haven't found a fortran compiler yet that will accept that line.
>
> Both the Control Data FTN 4 (1966 plus extensions, such as
>expressions in iolists) and FTN 5 (1977) compilers accept the construct.
> The WRITE statement corresponds to FORTRAN 77. The FORMAT should
>be changed to (i3) or (1x,i2), since FORTRAN 77 does not permit a "-" as a
>carriage control.
> Peter Montgomery
I think the f77 compiler is expecting an implied DO and then barfing when it
doesn't get one. VMS Fortran swallows this OK. If the write is changed to
something like
write(6,10) (-1,i=1,1)
f77 is happy.
But yes it is a bug.
My favorite I/O bug is
character*10 buf
integer num
buf = '12'
read(buf,'(I2)',err=20) num
write(6,*)num
stop
20 write(6,*)'Error!',num
stop
end
The output will be
Error! 12
[can anybody figure out WHY, and/or suggest a patch? Oh yes, if you do
read(buf,'(I2)',iostat=i) num
you get a core dump. Both Berkeley and AT&T Unix f77's are guilty of this.
If the formatted I/O is done from a file it works fine; only with internal
I/O it seems to barf.]
--
------------------------------- Disclaimer: The views contained herein are
| dan levy | yvel nad | my own and are not at all those of my em-
| an engihacker @ | ployer or the administrator of any computer
| at&t computer systems division | upon which I may hack.
| skokie, illinois |
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site ttrdc.UUCP Path: arc1-ca.pugleaf.net!utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!ltuxa!ttrdc!levy From: levy@ttrdc.UUCP (Daniel R. Levy) Newsgroups: net.lang.f77 Subject: Re: Minor I/O bug (and my favorite f77 I/O bug) Message-ID: <670@ttrdc.UUCP> Date: Fri, 3-Jan-86 22:59:13 EST Article-I.D.: ttrdc.670 Posted: Fri Jan 3 22:59:13 1986 Date-Received: Sat, 4-Jan-86 17:14:10 EST References: <3117@sdcc3.UUCP> <247@xanth.UUCP> <115@sdcsmb.UUCP> Organization: AT&T, Computer Systems Division, Skokie, IL Lines: 56