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Date: Fri, 18 May 2012 23:14:04 +0100
From: "Richard W.M. Jones" <rich@annexia.org>
To: Francois Berenger <berenger@riken.jp>
Cc: caml-list <caml-list@inria.fr>,
	batteries-devel@lists.forge.ocamlcore.org,
	OCaml Beginners List <ocaml_beginners@yahoogroups.com>
Message-ID: <20120518221404.GA26540@annexia.org>
References: <4FB1B5F3.3080908@riken.jp>
 <4FB1B60F.3060408@riken.jp>
 <4FB1BB82.6010900@riken.jp>
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User-Agent: Mutt/1.5.20 (2009-06-14)
Subject: Re: [Caml-list] Any library for reading/writing compressed files?

On Tue, May 15, 2012 at 11:12:18AM +0900, Francois Berenger wrote:
> Hello,
> 
> What's the gold standard in OCaml to read/write
> compressed files?
> 
> I found this: http://forge.ocamlcore.org/projects/camlzip/
> 
> Wouldn't it be possible that the Marshall module
> had an option to allow compression of the marshalled
> values?
> Or is there a simple way to achieve this?

If it's for Unix, then just open a pipe to or from an external
compression filter, eg:

  open Unix
  open Printf

  let () =
    let output = "output.xz" in
    let chan =
      open_process_out (sprintf "xz --best > %s"
                            (Filename.quote output)) in
    output_value chan 42;
    let status = close_process_out chan in
    (* some code here to check status was ok *)
    ()

(Also a good way to generate images from OCaml programs: pipe
to pnmto* programs).

Rich.

-- 
Richard Jones
Red Hat