Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!shadooby!samsung!gem.mps.ohio-state.edu!rpi!leah!rds95
From: rds95@leah.Albany.Edu (Robert Seals)
Newsgroups: comp.sys.ibm.pc
Subject: Bug in Turbo C "printf"; potentially serious. I think.
Keywords: rounding, I better be right
Message-ID: <2158@leah.Albany.Edu>
Date: 13 Nov 89 18:48:02 GMT
Organization: The University at Albany, Computer Services Center
Lines: 36


Hello,

[I was considering posting this to comp.lang.c, but there has been a
generally poor response to system specific discussion there...especially
about pcs.]

Consider this program:

/*
 * A program
 */
#include <stdio.h>

void main(void)
{
	double	g = 9.6;

	printf("%lf %.0lf %.1lf\n", g, g, g);
}
/*
 * end of a program
 */

I think that this should result in the line "9.600000 10 9.6\n" being printed
on standard output.

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