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From: "Dário Abdulrehman" <drehman31@gmail.com>
To: caml-list@yquem.inria.fr
Subject: reading/writing binary data
Date: Tue, 21 Nov 2006 11:34:52 +0000	[thread overview]
Message-ID: <6aeedf580611210334p41d2ba00jcceb00da3af0e3d2@mail.gmail.com> (raw)

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I am writing a program that encodes data in 32 bit ints.  Ideally I would
like to have 32 bit unsigned ints, but OCaml only has 31 bit signed ints.

I have a large binary file with the data that I will mmap with the
Bigarray.Array1.map_file function.

When I test the following code I am puzzled by the fact that Ocaml doesn't
give me back the int in the same format as I wrote it.

Why doesn't OCaml read back data in the same format?

I need to read the data fast without having to manipulate bits beyond the
minimum decoding to get my data back from the binary representation.

Thanks.

let test_data = open_out_bin "test.data" in
  output_binary_int test_data 1

let data =
  let fd = Unix.openfile "test.data" [Unix.O_RDONLY] 0 in
  Bigarray.Array1.map_file fd Bigarray.int Bigarray.c_layout false (-1)

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             reply	other threads:[~2006-11-21 11:34 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-11-21 11:34 Dário Abdulrehman [this message]
2006-11-21 13:15 ` [Caml-list] " Olivier Andrieu
2006-11-21 13:29   ` Dário Abdulrehman
2006-11-21 13:56     ` Dmitry Bely
2006-11-21 14:10       ` Jon Harrop
2006-11-21 19:57         ` Florian Hars

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