Re: [PATCH] hex <-> int conversion routines.

[george anzinger <george@mvista.com>]

Linus Torvalds wrote:
> 
> On Tue, 19 Feb 2002, Jakob Kemi wrote:
> >
> > I also added three other hex-functions that can replace a lot of duplicated code.
> >
> > int  hexint_nibble (char x);          // hex digit to int.
> > int  hexint_byte  (const char *src); // hex digit-pair to int.
> > char inthex_nibble (int x);           // int to hex digit.
> > void inthex_byte   (int x, char* dest);       // int to hex digit pair.
> 
> Is there any reason to do all of this?
> 
> I suspect 99% of all users can (and probably should) be replaced with
> "sscanf()" instead. Which does a lot more, of course, and is not the
> fastest thing out there due to that, but anybody who does hex->int
> conversion inside some critical loop is just crazy.
> 
>                 Linus
> 

So maybe a wrapper or two:

#define hexint_nibble(x) {int y; sscanf(&x,"%1xl",&y); y}
#define hexint_byte(x)   {int y; sscanf(x,"%2xl",&y); y}

#define inthex_nibble(x) {char y[2]; sprintf(&y,"%1x",x); y[1]}
#define inthex_byte(x,dest)       sprintf(dest,"%02x",x)

Untested, of course.
-- 
George           george@mvista.com
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