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From: Dmitry Bely <dbely@mail.ru>
To: caml-list@inria.fr
Subject: Re: [Caml-list] camlidl - character arrays?
Date: Fri, 19 Jul 2002 08:38:20 +0400	[thread overview]
Message-ID: <65zcgwn7.fsf@mail.ru> (raw)
In-Reply-To: <20020719011110.49051.qmail@web13405.mail.yahoo.com> (Brian Naylor's message of "Thu, 18 Jul 2002 18:11:10 -0700 (PDT)")

Brian Naylor <bwv211mail@yahoo.com> writes:

> I am trying to use CamlIDL for a C function like the following:
>
>     int foo (unsigned char [16]);
>
> If I write my CamlIDL file like this:
>
>     int foo ([in,string] unsigned char s [16]);
>
> The code does a check like this:
>
>     if (string_length(_v_s) >= 16) invalid argument("foo");
>
> The problem is that this is NOT a null-terminated string - it is exactly 16
> bytes of data.

You have two options here:

1. Don't use "string" attribute and pass OCaml character array (not string)
to your function or
2. Declare it as
     int foo ([string] unsigned char s[17]);
As C arrays are passed by the pointer, your C function will never know that
the trailing '\0' is there.

Dmitry Bely


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      reply	other threads:[~2002-07-19  4:45 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-07-19  1:11 Brian Naylor
2002-07-19  4:38 ` Dmitry Bely [this message]

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