[Toybox] [PATCH] count.c: Human readable -h option and MAYFORK

[enh]

On Fri, Oct 27, 2023 at 2:42 AM Rob Landley <rob at landley.net> wrote:
>
> On 10/26/23 18:33, enh wrote:
> > On Tue, Oct 24, 2023 at 12:31 AM Rob Landley <rob at landley.net> wrote:
> >> Possibly the test is wrong, and I should change it to call "echo -n" and check
> >> for 'yyy'. How either way proves they ran in parallel is unclear...
> >
> > (yeah, if _other_ echo's aren't atomic, it probably doesn't make sense
> > for you to bend over backwards to make yours atomic.)
>
> Well, other echo's _are_ atomic, "for the first 500 characters" or similar.
>
> $ strace /bin/echo one two three |& grep write
> write(1, "one two three\n", 14one two three
>
> They stop being atomic when we exceed their stdio buffer size (which is
> undocumented and variable)...
>
> $ strace /bin/echo $(seq 1 10000) |& grep write | wc -l
> 12
>
> and nothing's going to be atomic if it exceeds the kernel's pipe buffer size
> (which is kernel version specific and changeable with ulimit...
>
> But not being atomic for a simple case like this smells likely to break other
> stuff. Alas "smells" is not portably regression-testable.

true, but my usual argument of "...but at least you'll have the same
behavior as the other implementations _on that specific system_" still
holds.

(but, yes, it's pretty clear that the toybox tests shouldn't be
relying on what yes/echo may or may not actually do in practice...)

> Rob