RE: How to convert record?

["Beard, Frank" <beardf@spawar.navy.mil>]

One other thing you might want to consider:


procedure Write_ABCD (the_Command : Command) is

   Length : Posix.IO_Count :=
Posix.IO_Count(the_Command'size/Posix.Posix_Character'size);
   Buffer : IO_Buffer (1 .. positive(length));
   for Buffer use at the_Command'address;

begin

   POSIX.IO.write (File_Descriptor, Buffer, Length);

end Write_ABCD;


I've used it on both Windows and a couple of Unix flavors without
any problems, but we were always communicating between homogenous 
platforms (same hardware, same OS).  If you are in a heterogeneous
environment, you have to use a different method, but you have the
same problem with Unchecked_Conversion.

I like it because it's fairly straight forward and it doesn't copy
data like Unchecked_Conversion, which is particularly good when
dealing with large buffers.

Frank


-----Original Message-----
From: joseph_kwan@greenlime.com [mailto:joseph_kwan@greenlime.com]


Hello,

I just started to learn Ada and have been playing/working with Ada for
two weeks now.

I want to send a command buffer to serial port using florist's POSIX
interface but I have encountered problems in converting record to
POSIX.IO.IO_Buffer or Ada.Streams.Stream_Element_Array. How can I
overcome this problem?

package ABCD is

   type Command is
      record
          A : Character;
          B : Character;
          C : Integer;
          D : Long_Integer;
      end record;    -- total 8 bytes;

...
end ABCD;


POSIX.IO.write (File_Descriptor, Command, Length);

where 

   procedure Write
     (File           : in File_Descriptor;
      Buffer         : in IO_Buffer;
      Last           : out POSIX.IO_Count;
      Masked_Signals : in POSIX.Signal_Masking
                     := POSIX.RTS_Signals);

I have searched the CLA but do not find any solutions. Can you please
help?

Thank you.
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