Confused by segfault with legitimate call to strerror(3) on amd64 / sysctl (3) setting `odd' errno's

[Christian Kandeler]

On Friday 16 January 2009 09:53, Christoph Mallon wrote:

> > int
> > main() {
> >
> >         int mib[4];
> >
> >         size_t len;
> >
> >         if (sysctlnametomib("kern.ipc.shmmax", mib, &len) != 0) {
> >                 printf("Errno: %d\n", errno);
> >                 errx(errno, "Error: %s", strerror(errno));
>
> The use of errno is wrong. printf might change errno. 

I don't think printf() can set errno. And even if it could, it 
wouldn't matter, because C has call-by-value semantics.

Christian