Hi Thorsten,
On Thu, Mar 20, 2025 at 12:52:07AM +0100, Thorsten Glaser wrote:
> On Thu, 20 Mar 2025, Alejandro Colomar wrote:
>
> >> At the same time, disallowing a leading '-' sign
> >> is a benefit as well. I consider it a misfeature that strtoul() parses
> >> "-3" successfully and returns ULONG_MAX-2, which was most certainly
> >> not intended by the user.
> >
> >Agree; it is a misfeature.
>
> What?
>
> From a user’s PoV, this is hugely useful, and many other
> read-unsigned-integer-value routines handle this similarily
> (of course using whatever range they have) and C also defines
> this, so from an implementor’s PoV this is no trouble.
Can you clarify how this is useful as a programmer? I have replaced
*all* calls to strtoul(3) et al. in shadow-utils by my strtou_noneg(),
and never ever saw a valid use case of that feature.
> The other user’s PoV thing would be to allow 0x prefixing,
> but that needs an entire duplication of the inner loop, so
> I can see why people would want to exclude that.
I don't understand what you mean. strtou(3) supports 0x strings as long
as you specify 0 or 16 as the base.
alx@devuan:~/tmp$ cat hex.c
#include <bsd/inttypes.h>
#include <stdio.h>
int
main(void)
{
int status, n;
char *end;
n = strtou("0xF", &end, 0, 0, 1000, &status);
printf("%d\n", n);
printf("%s\n", end);
printf("%d\n", status);
n = strtou("0xF", &end, 16, 0, 1000, &status);
printf("%d\n", n);
printf("%s\n", end);
printf("%d\n", status);
}
alx@devuan:~/tmp$ gcc -Wall -Wextra hex.c -lbsd
alx@devuan:~/tmp$ ./a.out
15
0
15
0
Have a lovely night!
Alex
--
<https://www.alejandro-colomar.es/>
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