On 18/01/2021 15:15, Martin Gregorie wrote:
> On Mon, 18 Jan 2021 14:02:33 +0000, Pancho wrote:
>
>>> About -W : according to the manpage for the awk version I'm using,
>>> 5.0.1, -W has nothing to do with waiting for anything. All it does is
>>> to change the option marker from - to --
>>>
>>> I'm using Raspbian Buster, default awk is mawk 1.3.3.
>>
>> Perhaps that explains our different experience. mawk buffering doesn't
>> appear to be line buffering by default, i.e it buffers blocks somewhere
>> between 2 to 3kB (whatever the correct name for that is).
>>
>> What OS are you using?
>
> Fedora 32 for these tests, which uses awk 5.0.1  - The Buster awk is very
> old, so raising a bug requesting an upgrade to the latest awk may be a
> good idea.
>
> Running "man 7 pipe" tells you almost everything you'd want to know about
> pipes and that the implementation changed at Linux 2.6.11 - Fedora 32 is
> using the Linux 5.9.16 kernel.
>

Yeah that is kind of the point, I'm a mediocre old programmer, I don't
want to know everything about everything. What I want is an easy life. I
want a basic technique to work, reliably, environment agnostically as
possible.

I think this clarifies in my mind why I wouldn't ever use this technique
to observe events in practice. It is too fragile.

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