Re: [PATCH v8 02/10] lib: kstrtox: add kstrntoull() helper

[Rodrigo Alencar]

On 26/03/04 11:41AM, Rodrigo Alencar wrote:
> On 26/03/04 10:16AM, David Laight wrote:
> > On Tue, 03 Mar 2026 13:27:07 +0000
> > Rodrigo Alencar via B4 Relay <devnull+rodrigo.alencar.analog.com@xxxxxxxxxx> wrote:
> > 
> > > From: Rodrigo Alencar <rodrigo.alencar@xxxxxxxxxx>
> > > 
> > > Add kstrntoull() function, which converts a string to an ULL with a max
> > > character limit. The function is an alternative integer parsing function
> > > that does not require a null-terminated string. It becomes a better option
> > > over simple_strtoull() or kstrtoull() when parsing integers from a buffer
> > > with custom delimiters without having to create temporary copies.
> > > The function is consumed inside the implementation _kstrtoull(),
> > > promoting reuse.
> > 
> > If you've got custom delimiters use a function that returns a pointer
> > to the character that terminated the conversion.
> > They save you having to find the delimiter as well as taking a copy.
> 
> understood, how about this prototype then:
> 
> const char __must_check *kstrntoull(const char *s, unsigned int base,
> 				    unsigned long long *res, size_t max_chars); 
> 
> to be used like:
> 
> 	end = kstrntoull(s, base, &res, INT_MAX);
> 	if (IS_ERR(end)) {
> 		/* return or handle error */
> 		return PTR_ERR(end);
> 	}

Hi David,

Do you have any other feedback? the function prototype can also be changed as
follows:

int __must_check *kstrntoull(const char *s, const char **endp, unsigned int base,
			     unsigned long long *res, size_t max_chars);

so that a pointer to the terminated character is passes as a parameter.
which one would be the preference?

-- 
Kind regards,

Rodrigo Alencar