Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!swrinde!ucsd!ogccse!orstcs!jacobs.CS.ORST.EDU!moorer
From: moorer@jacobs.CS.ORST.EDU (Rocky Moore)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Bug in Turbo C "printf"; potentially serious. I think.
Keywords: rounding, I better be right
Message-ID: <13803@orstcs.CS.ORST.EDU>
Date: 15 Nov 89 13:39:26 GMT
References: <2158@leah.Albany.Edu>
Sender: usenet@orstcs.CS.ORST.EDU
Reply-To: moorer@jacobs.CS.ORST.EDU.UUCP (Rocky Moore)
Organization: Oregon State University - CS - Corvallis Oregon
Lines: 21

In article <2158@leah.Albany.Edu> you write:
> >Turbo C in the small model prints "1" instead of "10"; it seems that whenever
>the print format is "%.0lf"  and the argument rounds to a power of 10,
>printf and fprintf (haven't tried cprintf or sprintf) print 1 too few '0's.
>
>This is bad news.
>
>Workaround: Don't use "%.0lf"!!!
>
>rob

The problem is certainly a bug.  It only happens (in any model) when you have
a number which when rounded off will increase the number of leading digits (
e.g. 999.9 9999.9 99.9 ect)..

You should also note note to EVER forget to include math.h if you use something
like the sine() or cos() functions.  You will find that the printf() will seem
to print just junk at times instead of the values supplied.  It can cost you
many hours of debugging when you have just forogt a header file.

-Rocky Moore     moorer@jacobs.cs.orst.edu        - Let those who ride decide!