strtod (and atof) on hex numbers

Corinna Vinschen corinna-cygwin@cygwin.com
Tue Jun 20 18:16:00 GMT 2006


This is a newlib issue.  I redirected this to the appropriate mailing
list newlib AT sourceware DOT org.


On Jun 20 13:00, Paul Biggar wrote:
> Hi,
> 
> atof (and hence strtod) on hexadecimal numbers results in 0.0 (errno
> of 0). This may be related to an old issue where NaN isnt correctly
> parsed. I believe it isnt correct behaviour:
> 
> http://www.opengroup.org/onlinepubs/000095399/functions/atof.html
> 
> 
> 
> I've tested it for integers in the range 0x8000000 to 0xFFFFFFFF. It
> works properly on
> 
> ubuntu dapper, gcc 4.1 on i386;
> debian stable, gcc 3.3 on amd64
> sunos ?, gcc 3.4 on sparc
> 
> I'm using standard cygwin distribution, which uses gcc 3.4.4 (cygming 
> special)
> 
> Sample code:
> 
> #include "limits.h"
> #include <iostream.h>
> #include "errno.h"
> 
> int main()
> 
> {
>        cout << ULONG_MAX << endl;
>        cout << 0xFFFFFFFF << endl;
> 
>        errno = 0;
>        cout << atof("0xFFFFFFFF") << endl;
>        cout << errno << endl;
> 
>        errno = 0;
>        cout << strtod("0xFFFFFFFF", NULL) << endl;
>        cout << errno << endl;
> 
> }
> 
> 
> Is this being fixed? I could find a mention of it before. Does anyone
> know a simple workaround?
> 
> Thanks
> Paul

Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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