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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: problems with interfacing c
Newsgroups: comp.lang.ada
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Date: Fri, 28 Jan 2011 10:44:58 +0100
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On Thu, 27 Jan 2011 16:39:50 -0800 (PST), Stoik wrote:

> The other question is - how to use the C bindings properly in such a
> case?

You should probably use _read, because fread needs a file descriptor rather
than just number.

   with Interfaces.C;  use Interfaces.C;
   with System;        use System;
...
   function Read (FD : int; Buffer : Address; Count : size_t) return int;
   pragma Import (C, Read, "_read");
...

Now actual reading:

   Buffer : String (1..100_000);
   Bytes  : int;
begin
   Bytes := Read (0, Buffer'Address, Buffer'Length);

Buffer (1..Integer (Bytes)) is the data read, empty when error. Here I
assume that Character = char, so it might be non-portable, but who cares in
these meaningless contests?

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de