Bug 6453

Summary: strtod() is buggy
Product: [Retired] Red Hat Linux Reporter: lars
Component: glibcAssignee: Cristian Gafton <gafton>
Status: CLOSED NOTABUG QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: 6.2   
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OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2000-03-04 22:21:09 UTC Type: ---
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Description lars 1999-10-28 06:53:37 UTC
Morning, as we just discussed on IRC, strtod("0x0a") is supposed to return 0 according to the man page,
but it does return 1.25.
This manifests itself in breaking Perl for example,
# perl -e 'print "0x0a"+0,"\n";'
1.25

Comment 1 Bernhard Rosenkraenzer 2000-02-17 20:10:59 UTC
I've verified it's indeed a glibc problem, and still present in dist-6.2


#include <stdlib.h>
main() {
	double a=strtod("0x0a", NULL);
	printf("%f\n", a);
}

Comment 2 Cristian Gafton 2000-03-04 22:21:59 UTC
Well, ISO C99 specifies that:

      [#5]  If  the  subject sequence has the hexadecimal form and
       FLT_RADIX is a power of 2,  the  value  resulting  from  the
       conversion is correctly rounded.

      7.20.1.3                   Library                  7.20.1.3

In binary notation, 0x0A = 1010 = 1.25 (for FLT_RADIX=2, whcih is the default)

Not a bug, just what the standard mandates.