Subject: lib/21691: sscanf(3) %i format does not work properly with -ve hex numbers
To: None <gnats-bugs@gnats.netbsd.org>
From: None <thorpej@shagadelic.org>
List: netbsd-bugs
Date: 05/26/2003 14:11:26
>Number: 21691
>Category: lib
>Synopsis: sscanf(3) %i format does not work properly with -ve hex numbers
>Confidential: no
>Severity: serious
>Priority: high
>Responsible: lib-bug-people
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Mon May 26 21:12:00 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator: Jason R Thorpe
>Release: NetBSD 1.6T
>Organization:
Wasabi Systems, Inc.
>Environment:
System: NetBSD swinger.shagadelic.org 1.6T NetBSD 1.6T (SWINGER) #230: Tue May 13 10:28:44 PDT 2003 thorpej@yeah-baby.shagadelic.org:/u1/netbsd/src/sys/arch/i386/compile/SWINGER i386
Architecture: i386
Machine: i386
>Description:
ISO C says about sscanf()'s %i format:
``
i Matches an optionally signed integer, whose format is the
same as expected for the subject sequence of the strtol()
function with the value 0 for the base argument. The
corresponding argument shall be a pointer to a signed integer.
''
Our sscanf() does not function properly. When it encounters a
"-0x..." number, it stops parsing after first 0, advancing the
input pointer to the x.
strtol() appears functions properly; this must be a problem with
__svfscanf_unlocked()'s checking of the input stream before it
calls the conversion function.
>How-To-Repeat:
Run the following test program.
#include <stdio.h>
#include <stdlib.h>
char string[] = "-0xff";
int
main()
{
long foo;
int nchars;
sscanf(string, "%li%n", &foo, &nchars);
if (foo != -255 || string[nchars] != '\0')
abort();
return 0;
}
>Fix:
Not provided.
>Release-Note:
>Audit-Trail:
>Unformatted: