Date: Wed, 15 Jan 1997 08:40:01 -0800 (PST) From: davidn@unique.usn.blaze.net.au (David Nugent) To: freebsd-bugs Subject: Re: bin/2502: Unable to sscanf first integer value. Message-ID: <199701151640.IAA10123@freefall.freebsd.org>
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The following reply was made to PR bin/2502; it has been noted by GNATS.
From: davidn@unique.usn.blaze.net.au (David Nugent)
To: scrutchfield@ifusion.com
Cc: freebsd-gnats-submit@freebsd.org
Subject: Re: bin/2502: Unable to sscanf first integer value.
Date: Thu, 16 Jan 1997 03:23:01 +1100
scrutchfield@ifusion.com writes:
> I am unable to sscanf correctly 2 integers from a string. A Sample
> program that recreates the problem is shown below. This is a problem
> in both libc and libc_r.
No, it is a problem with your code, not libc.
> #include <stdio.h>
> #include <string.h>
> #include <stdlib.h>
>
> main()
> {
> char *tmp = "999 12346";
> char *ptr;
> unsigned short x;
> unsigned short y;
> unsigned short z;
> unsigned int a;
> int result;
>
> result = sscanf ( tmp, "%d %d", &x, &y );
You're scanning integers, and this is what sscanf expects.
You're passing it pointers to 16-bit, not 32-bit, quantities.
'x' is "zeroed" when the value 12346 (32-bit) is written to y,
as the following fprintf() shows.
> z = strtol ( tmp, &ptr, 0 );
> a = atoi ( tmp );
And I assume this is supposed to be 'ptr', not 'tmp'.
> (void)fprintf ( stderr, "x(%d)y(%d)z(%d)a(%d)\n", x, y, z, a );
> exit ( 0 );
> }
The following is a "fixed" version of your code which simply
changes the integral variables to the 32-bit quantities that
sscanf expects, which works fine.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
main()
{
char *tmp = "999 12346";
char *ptr;
int x;
int y;
int z;
int a;
int result;
result = sscanf ( tmp, "%d %d", &x, &y );
z = strtol ( tmp, &ptr, 0 );
a = atoi ( ptr );
(void)fprintf ( stderr, "x(%d)y(%d)z(%d)a(%d)\n", x, y, z, a );
exit ( 0 );
}
Regards,
David Nugent - Unique Computing Pty Ltd - Melbourne, Australia
Voice +61-3-9791-9547 Data/BBS +61-3-9792-3507 3:632/348@fidonet
davidn@freebsd.org davidn@blaze.net.au http://www.blaze.net.au/~davidn/
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