------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- Cheddar is a GNU GPL real-time scheduling analysis tool.
-- This program provides services to automatically check schedulability and
-- other performance criteria of real-time architecture models.
--
-- Copyright (C) 2002-2023, Frank Singhoff, Alain Plantec, Jerome Legrand,
--                          Hai Nam Tran, Stephane Rubini
--
-- The Cheddar project was started in 2002 by
-- Frank Singhoff, Lab-STICC UMR 6285, Université de Bretagne Occidentale
--
-- Cheddar has been published in the "Agence de Protection des Programmes/France" in 2008.
-- Since 2008, Ellidiss technologies also contributes to the development of
-- Cheddar and provides industrial support.
--
-- The full list of contributors and sponsors can be found in README.md
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 2 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program; if not, write to the Free Software
-- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
--
--
-- Contact : cheddar@listes.univ-brest.fr
--
------------------------------------------------------------------------------
-- Last update :
--    $Rev$
--    $Date$
--    $Author: singhoff $
------------------------------------------------------------------------------
------------------------------------------------------------------------------

--------------------------------------------------------------------------------
-- PACKAGE: Pipe Commands
--
-- PURPOSE: Provide a thick Ada binding to the UNX / WIN32 popen and pclose
--          commands. This allows an Ada program to call another program and
--          either send output to that program, or read input from that
--          program.
--
-- USAGE: Execute the command with mode read_file when you want to read the
-- output of the program you start. Execute the command with write_mode when
-- you want to write to the input of the program you start.
--
-- EXCEPTIONS:
--   Access_Error => Raised when a mode violation is attempted
--   End_Of_file  => Raised when the pipe is closed upon a read
--------------------------------------------------------------------------------

with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
with System;

package pipe_commands is

   type stream is private;

   type io_mode is (read_file, write_file);

   function execute (command : in String; io_type : in io_mode) return stream;

   function read_next (fromfile : in stream) return Unbounded_String;

   procedure write_next (tofile : in stream; message : in String);

   procedure close (openfile : in stream);

   access_error : exception; -- Raised when attempt is made to violate IO_MODE
   end_of_file  : exception; -- Raised on detection of End_of_file during read

private

   subtype files is System.Address; -- Corresponds to a C file pointer

   type stream is record
      filestream : files;
      mode       : io_mode;
   end record;

end pipe_commands;