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Subject: Re: Hardware independent programming
Newsgroups: comp.lang.ada
References: <5ef9712d$0$1221$e4fe514c@news.kpn.nl>
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From: ldries46 <bertus.dries@planet.nl>
Date: Tue, 30 Jun 2020 08:35:15 +0200
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This is how such a Package could look like:

with Ada.Environment_Variables; use Ada.Environment_Variables;
with Debugging;                 use Debugging;

package body Hardware is

    function Operation_System return Unbounded_String is
       OS : Unbounded_String := To_Unbounded_String("No System");
    begin
       if Exists("OS") then
          OS := To_Unbounded_String(Value("OS"));
       end if;
       return OS;
    end Operation_System;

    function Resolution(Screen_nr : positive := 1) return 
Screen_resolution is
       Scr  : Screen_resolution;
       str  : Unbounded_String;
       Name : Unbounded_String;
    begin
       str := To_Unbounded_String(integer'image(Screen_nr));
       while Slice(str, 1, 1) = " " loop
          str := To_Unbounded_String(Slice(str, 2, Length(str)));
       end loop;
       Name := To_Unbounded_String("Screen_Width_") & str;
       if Exists(To_String(Name)) then
          Scr.width := integer'value(Value(To_String(Name)));
          Print_Line(Name);
       end if;
       Name := To_Unbounded_String("Screen_Heigth_") & str;
       if Exists(To_String(Name)) then
          Scr.heigth := integer'value(Value(To_String(Name)));
          Print_Line(Name);
       end if;
       return Scr;
    end Resolution;

end Hardware;