[Caml-list] Setting Pervasive's stderr to unbuffered as default?

[Caml-list] Setting Pervasive's stderr to unbuffered as default?

[Oliver Bandel]

Hello,

stderr on Unix is unbuffered by default.

In OCaml, all the Channels from Pervasives are buffered by default,
and flush-function must be used.
This issue is annoying me since ages...

Is there a way to set Unix-like-behaviour (unbuffered stderr =>  
unbuffered Pervasives.stderr)
as default?

Something like setbuf(3) / setvbuf(3) for OCaml's pervasives?

Would a feature-wish for this feature have any chance of success?

Ciao,
    Oliver

Re: [Caml-list] Setting Pervasive's stderr to unbuffered as default?

[Sébastien Hinderer]

Hi,

Oliver Bandel (2015/08/23 02:19 +0200):
> Hello,
> 
> stderr on Unix is unbuffered by default.
> 
> In OCaml, all the Channels from Pervasives are buffered by default,
> and flush-function must be used.
> This issue is annoying me since ages...

[...]

I'd also prefer an unbuffered stderr, finding it more intuitive.

Thanks for havign mentionned that,
Sébastien.

Re: [Caml-list] Setting Pervasive's stderr to unbuffered as default?

[Gerd Stolpmann]

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I cannot follow. Pervasives.stderr is unbuffered; however (see
pervasives.ml):

let print_endline s =
  output_string stdout s; output_char stdout '\n'; flush stdout
let print_newline () = output_char stdout '\n'; flush stdout

let prerr_endline s =
  output_string stderr s; output_char stderr '\n'; flush stderr
let prerr_newline () = output_char stderr '\n'; flush stderr

So far I know these are the only functions doing an implicit flush, and
they are doing it for both stdout and stderr.

Gerd


Am Montag, den 24.08.2015, 14:19 +0200 schrieb Sébastien Hinderer:
> Hi,
> 
> Oliver Bandel (2015/08/23 02:19 +0200):
> > Hello,
> > 
> > stderr on Unix is unbuffered by default.
> > 
> > In OCaml, all the Channels from Pervasives are buffered by default,
> > and flush-function must be used.
> > This issue is annoying me since ages...
> 
> [...]
> 
> I'd also prefer an unbuffered stderr, finding it more intuitive.
> 
> Thanks for havign mentionned that,
> Sébastien.
> 

-- 
------------------------------------------------------------
Gerd Stolpmann, Darmstadt, Germany    gerd@gerd-stolpmann.de
My OCaml site:          http://www.camlcity.org
Contact details:        http://www.camlcity.org/contact.html
Company homepage:       http://www.gerd-stolpmann.de
------------------------------------------------------------


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Re: [Caml-list] Setting Pervasive's stderr to unbuffered as default?

[Sébastien Hinderer]

Hi,

Gerd Stolpmann (2015/08/25 13:09 +0200):
> I cannot follow. Pervasives.stderr is unbuffered;

How do you know, actually?

If it would be, then th flushes in the functions dealing with stderr
that you showed wold not be necessary,would they?
Thanks!

Sébastien.

Re: [Caml-list] Setting Pervasive's stderr to unbuffered as default?

[Xavier Leroy]

On 25/08/2015 13:09, Gerd Stolpmann wrote:
> I cannot follow. Pervasives.stderr is unbuffered; however (see
> pervasives.ml):

Just to avoid possible misunderstandings:

- All Pervasives.out_channel are buffered.  There is no such thing
  as an unbuffered out_channel.
- A few "print" functions from Pervasive flush explicitly when
  printing a newline (because those functions are often used for
  interactive I/O).
- The "%!" modifier for printf also forces a flush.

Hope it's clearer now.

- Xavier Leroy