Re: Examples of concurrent coproc usage?

[Martin D Kealey]

On Mon, 22 Apr 2024, 09:17 Carl Edquist, <edquist@cs.wisc.edu> wrote:

> When I say "token" I just mean a record with whatever delimiter you're
> referring to using.


Ok that makes sense.

 Assuming the reading stops after consuming the first delimiter (which is
> necessary for the 'read' builtin), then you end up with one system call per
> line or record or token or whatever you want to call it.
>

That's what I was initially thinking of, but now I wonder whether the new
kernel call should also accept a record count.

[…] I was saying the shell is crippled when limited to builtins; eg, a
> read/printf loop compared to simply running cat.
>

I would hope that mapfile/readarray could do better, since it's not
obligated to leave anything in the input stream.

But yeah currently a pipe with a series of records and multiple
> cooperating/competing readers perhaps only works if the records have a
> fixed size. A new readd[elim] system call like you're talking about would
> allow safely reading a single variable-length record at a time.
>

There are other options, such as length-prefixed records, or tagged (typed)
records, but of course those aren't POSIX text files.

>
This starts to make me wonder whether mediated stdin could be more
efficient?

-Martin