From:	MERC::"uunet!CRVAX.SRI.COM!RELAY-INFO-VAX" 16-DEC-1992 00:18:16.05
To:	info-vax@kl.sri.com
CC:	
Subj:	InterViews 3.1b3 doc: VAXCRTL doesn't like "%g" formatted input

I had problems with my VMS port of the InterViews 3.1-beta3 doc editor
which crashed either because of "divide by zero" or "floating overflow".

I've found that the formatted input routines in VAXCRTL don't like "%g".
They refuse to change the float's value and don't increment the return value
(success counter). I think that it is not a real bug, because table 2-2 of
the "VAX C Run-Time Library Reference Manual" (February 1991, VAX C 3.2 for
VMS 5.2 or higher) doesn't list "%g" as allowed for input.
But in fact, GCC relies on it, so it's not ANSI-C compatible.
BTW: We use GCC 2.2.2 and VMS 5.5-1 .

Suggested Workaround:
Change all "%g" to "%e" in input formatting strings.

I've done this in: (original UNIX names)
src/bin/doc/document.c		(2 lines)
src/bin/doc/idrawimage.c	(3 lines)

The following shows what's going on:
=========================================================================
#include <stdio.h>
main() {
float f;
int s;
printf("%g\n", f);
s = sscanf("10.0","%g",&f);
printf("%g %d\n", f, s);
s = sscanf("10.0","%e",&f);
printf("%g %d\n", f, s);
}
=========================================================================
$ run main
2.350989e-38
2.350989e-38 0
10 1
=========================================================================

I'll post this to both comp.os.vms and comp.windows.interviews .


Thanks, Heribert (dahms@ifk20.mach.uni-karlsruhe.de)