Messages in this thread | | | Date | Sat, 14 May 2022 13:11:40 +0200 | From | Max Staudt <> | Subject | Re: [PATCH v6] can, tty: can327 CAN/ldisc driver for ELM327 based OBD-II adapters |
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On Sat, 14 May 2022 12:14:24 +0900 Vincent Mailhol <vincent.mailhol@gmail.com> wrote:
> But I still think it is possible to do pointer arithmetic. > > len = strnchr(elm->rxbuf, elm->rxfill, '\r') - elm->rxbuf; > (I let you check that I did not do an off by one mistake). > > The above should also work with memchr(). Although the C standard > doesn't allow pointer arithmetic on void *, GNU C adds an extension > for that: https://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html > > As I said before, your for loop is not fundamentally wrong, this is > just not my prefered approach. You have my suggestion, choose what you > prefer.
Yeah, this is the arithmetic that I'd like to avoid here. In my opinion, it is clearer with indices.
If I were searching through a UTF-8 string (i.e. with variable width chars), that'd be another matter entirely IMHO, and I'd rely on C library functions that know more about UTF that I do. But it's really just naked ASCII bytes this time.
...unless memchr() may be faster than the loop? Could this happen?
Max
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