On Sun, 2014-10-19 at 14:19 +0200, Rickard Strandqvist wrote: > 2014-10-19 3:38 GMT+02:00 Joe Perches <[email protected]>: > > On Sun, 2014-10-19 at 00:03 +0200, Rickard Strandqvist wrote: > >> Added a function strzcpy which works the same as strncpy, > >> but guaranteed to produce the trailing null character. > >> > >> There are many places in the code where strncpy used although it > >> must be zero terminated, and switching to strlcpy is not an option > >> because the string must nonetheless be fyld with zero characters. > > [] > >> diff --git a/lib/string.c b/lib/string.c > > [] > >> +char *strzcpy(char *dest, const char *src, size_t count) > >> +{ > >> + char *tmp = dest; > >> + > >> + while (count) { > >> + if ((*tmp = *src) != 0) > >> + src++; > >> + tmp++; > >> + count--; > >> + } > >> + > >> + if (dest != tmp) > >> + *--tmp = '\0'; > >> + > >> + return dest; > >> +} > > > > why not > > > > char *strzcpy(char *dest, const char *src, size_t count) > > { > > strncpy(dest, src, count) > > if (count) > > dest[count - 1] = 0; /* or '\0' or whatever */ > > > > return dest; > > } > > > > maybe use static inline too. > > > > Hi Joe > > Yes this solution have also been discussed. > https://lkml.org/lkml/2014/10/16/682 > > Very possible that it is a better solution. > The code that I use in strzcpy is not the way I'd written it, but is > the same as in strncpy now. > > But as I understand it the real strncpy code is normally highly > optimized for the hardware it runs on. > Ex: arch/x86/lib/string_32.c
The fact that optimized strncpy variants exist for any platform is the argument _for_ using it in strzcpy. > But missing for x86 64 bit and Arm..? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
