Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!mrccrc!dcurtis
From: dcurtis@crc.ac.uk (Dr. David Curtis)
Newsgroups: comp.lang.c
Subject: Re: bug? in turbo c++
Message-ID: <511@tin.crc.ac.uk>
Date: 8 Mar 91 09:32:30 GMT
References: <MITCH.91Mar5134925@hq.af.mil> <1991Mar6.171424.17409@nntp-server.caltech.edu> <1991Mar6.173733.430@unhd.unh.edu>
Reply-To: dcurtis@crc.ac.uk (Dr. David Curtis)
Organization: MRC Human Genome Resource Centre
Lines: 30

In article <1991Mar6.173733.430@unhd.unh.edu> rg@msel.unh.edu (Roger Gonzalez) writes:
>the following program demonstrates this "bug":
>main()
>{
>    int     i;
>    long    j;
>
>    for (i = 0; i < 1000; i++, j = i*2)
>        printf("oh crud: %x %10d %x\r", i, j, i);
>}
>
>The third number printed is always zero.  It corrects itself if the
>second formatting string is %10ld.  Is this a new ansi-ism?  Will this
>behavior change to what my Unix cc fingers expect if I set it to K&R?
>Is it a bug?  I can see them arguing that it isn't a bug, but I find
>it an unpleasant nonbug at the very least.
>

Of course this isn't a bug. The only way it could possibly work as you
apparently intend if int and long were the same size. You seem to expect
printf() to know the size of the arguments which have been put on the
stack, but of course the only  way for it to do this is by providing if
with a (correct) format string.

Dave Curtis

Academic Department of Psychiatry,    Janet:       dc@UK.AC.UCL.SM.PSYCH
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