Re: Terminal Control (or System calls), unix

[jerry@jvdsys.stuyts.nl (Jerry van Dijk)]

dennison@telepath.com wrote:

: In article <3703F011.1DBB143C@cs.und.edu>,
:   "Sven E. Anderson" <anderson@cs.und.edu> wrote:

(note I careful I am about the attributions :-)

: > I am attempting to write a simple screen editor with Ada95 and would
: > like to suppress the tty echo (unix/linux).  A very simple solution
: > would be a system call to "stty -echo cbreak".  How might I make such
: > a call in Ada?

: If its a system call, you should be able to make it from Ada. However I think
: stty is typically a shell builtin, isn't it?

That does not matter, on Linux, you could use something like:

	with System;

	procedure No_Echo is

	   type Echo_Type is (On, Off);

	   procedure Set_Echo (Echo : in Echo_Type) is
   
	      procedure Execute (S : in String) is
	         procedure System (S : in System.Address);
	         pragma Import (C, System, "system");
	         C_String : constant String := S & ASCII.NUL;
	      begin
	         System (C_String'Address);
	      end Execute;
	      pragma Inline (Execute);
      
	   begin
	      if Echo = On then
	         Execute ("stty -echo cbreak");
	      else
	         Execute ("stty echo");
	      end if;
	   end Set_Echo;
   
	begin
	   null;
	end No_Echo;

--
-- Jerry van Dijk | Leiden, Holland
-- Team Ada       | jdijk@acm.org
-- see http://stad.dsl.nl/~jvandyk