strtod (and atof) on hex numbers

Jeff Johnston jjohnstn@redhat.com
Tue Jun 20 18:26:00 GMT 2006


This is a C99 extension to strtod over original ANSI C90 which is what 
newlib started with.  I'll start working on it, but don't expect 
anything too quick.

-- Jeff J.

Corinna Vinschen wrote:
> 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
> 


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