Re: How to use/obtain output from system commands (in an Ada program) ?

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On 2016-06-19 08:08, reinkor wrote:

> I am looking for a simple way to obtain output from "xmessage"
> (or dialog/kdialog) in my Ada program. Any good hints?

The package System.OS_Lib has procedures Spawn that are much more 
comfortable to use than system().

If you use GtkAda you can start xmessage or any other process with 
pipe-lined input/output/error. Then you will have callbacks to process 
them. It is also possible to use Gtk_Text_Buffer instead of callbacks.

http://www.dmitry-kazakov.de/ada/gtkada_contributions.htm#10.1

> A trivial way is to output to a file like in this test procedure:
>
> with Interfaces.C;
> with Interfaces.C.Strings;
> with Ada.Text_IO, Text_IO;
>
> procedure Test7 is
>    package C renames Interfaces.C;
>    use type C.char_array;
>    procedure system (Source : in  C.char_array);
>    pragma Import(C, system, "system");
>    use Ada.Text_IO, Text_IO;
>    file1 : File_Type;
> begin
>      system("xmessage -center Box1  -buttons label1:X,label2:y -print > choice_file1");

Add terminating ASCII NUL here.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de