Messages in this thread | | | Date | Thu, 31 Oct 2019 10:29:38 +0800 (CST) | From | "Liu Xiang" <> | Subject | Re:Re: [PATCH] lib: string: reduce unnecessary loop in strncpy |
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At 2019-10-30 22:59:58, "Rasmus Villemoes" <linux@rasmusvillemoes.dk> wrote: >On 30/10/2019 15.14, Liu Xiang wrote: >> Now in strncpy, even src[0] is 0, loop will execute count times until >> count is 0. It is better to exit the loop immediately when *src is 0. > >Please read "man strncpy". > >There's a reason the loop is written in that somewhat convoluted way: >The behavior of strncpy is mandated by the C standard, and if the src >string is shorter than the destination buffer, the rest must be >0-filled. So if we hit a nul byte before running out of count, we keep >copying that nul byte to the rest of the destination. > >Rasmus
Hi Rasmus,
Thanks for your explanation. I ignored the C library standard.
Regards
Liu Xiang
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