Re: Ada x <whatever> Datagram Sockets

["Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>]

On 2/8/19 9:35 PM, Rego, P. wrote:
>> What the OP needs to do is
>>
>> 1. Get Length, the length of the data.
>> 2. Create C : Interfaces.C.char_array (1 .. Length)
>> 3. Transfer the data into C
>> 4. Use Interfaces.C.To_Ada (C) to transform C into an Ada String

Now that I look at it in more detail, it's probably better to do something like

function To_String (Buffer : Ada.Streams.Stream_Element_Array) return String is
    Result : String (1 .. Buffer'Length);
    Last   : Natural := 0;
begin -- To_String
    Convert : for I in Buffer'range loop
       exit Convert when Buffer (I) = 0; -- If NUL terminated

       Last := Last + 1;
       Result (Last) := Character'Val (Buffer (I) );
    end loop Convert;

    return Result (1 .. Last);
end To_String;

Buffer : Ada.Streams.Stream_Element_Array (1 .. Big_Enough);
Last   : Ada.Streams.Stream_Element_Offset;
...
Receive_Socket (Socket => Socket, Item => Buffer, Last => Last);

Do_Something (To => To_String (Buffer (1 .. Last) ) );

-- 
Jeff Carter
"I've seen projects fail miserably for blindly
applying the Agile catechism: we're Agile, we
don't need to stop and think, we just go ahead
and code!"
Bertrand Meyer
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