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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- A D A . E N V I R O N M E N T _ V A R I A B L E S --
-- --
-- B o d y --
-- --
-- Copyright (C) 2009-2022, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with System.CRTL;
with Interfaces.C.Strings;
with Ada.Unchecked_Deallocation;
package body Ada.Environment_Variables is
-----------
-- Clear --
-----------
procedure Clear (Name : String) is
procedure Clear_Env_Var (Name : System.Address);
pragma Import (C, Clear_Env_Var, "__gnat_unsetenv");
F_Name : String (1 .. Name'Length + 1);
begin
F_Name (1 .. Name'Length) := Name;
F_Name (F_Name'Last) := ASCII.NUL;
Clear_Env_Var (F_Name'Address);
end Clear;
-----------
-- Clear --
-----------
procedure Clear is
procedure Clear_Env;
pragma Import (C, Clear_Env, "__gnat_clearenv");
begin
Clear_Env;
end Clear;
------------
-- Exists --
------------
function Exists (Name : String) return Boolean is
use System;
procedure Get_Env_Value_Ptr (Name, Length, Ptr : Address);
pragma Import (C, Get_Env_Value_Ptr, "__gnat_getenv");
Env_Value_Ptr : aliased Address;
Env_Value_Length : aliased Integer;
F_Name : aliased String (1 .. Name'Length + 1);
begin
F_Name (1 .. Name'Length) := Name;
F_Name (F_Name'Last) := ASCII.NUL;
Get_Env_Value_Ptr
(F_Name'Address, Env_Value_Length'Address, Env_Value_Ptr'Address);
if Env_Value_Ptr = System.Null_Address then
return False;
end if;
return True;
end Exists;
-------------
-- Iterate --
-------------
procedure Iterate
(Process : not null access procedure (Name, Value : String))
is
use Interfaces.C.Strings;
type C_String_Array is array (Natural) of aliased chars_ptr;
type C_String_Array_Access is access C_String_Array;
function Get_Env return C_String_Array_Access;
pragma Import (C, Get_Env, "__gnat_environ");
type String_Access is access all String;
procedure Free is new Ada.Unchecked_Deallocation (String, String_Access);
Env_Length : Natural := 0;
Env : constant C_String_Array_Access := Get_Env;
begin
-- If the environment is null return directly
if Env = null then
return;
end if;
-- First get the number of environment variables
loop
exit when Env (Env_Length) = Null_Ptr;
Env_Length := Env_Length + 1;
end loop;
declare
Env_Copy : array (1 .. Env_Length) of String_Access;
begin
-- Copy the environment
for Iterator in 1 .. Env_Length loop
Env_Copy (Iterator) := new String'(Value (Env (Iterator - 1)));
end loop;
-- Iterate on the environment copy
for Iterator in 1 .. Env_Length loop
declare
Current_Var : constant String := Env_Copy (Iterator).all;
Value_Index : Natural := Env_Copy (Iterator)'First;
begin
loop
exit when Current_Var (Value_Index) = '=';
Value_Index := Value_Index + 1;
end loop;
Process
(Current_Var (Current_Var'First .. Value_Index - 1),
Current_Var (Value_Index + 1 .. Current_Var'Last));
end;
end loop;
-- Free the copy of the environment
for Iterator in 1 .. Env_Length loop
Free (Env_Copy (Iterator));
end loop;
end;
end Iterate;
---------
-- Set --
---------
procedure Set (Name : String; Value : String) is
F_Name : String (1 .. Name'Length + 1);
F_Value : String (1 .. Value'Length + 1);
procedure Set_Env_Value (Name, Value : System.Address);
pragma Import (C, Set_Env_Value, "__gnat_setenv");
begin
F_Name (1 .. Name'Length) := Name;
F_Name (F_Name'Last) := ASCII.NUL;
F_Value (1 .. Value'Length) := Value;
F_Value (F_Value'Last) := ASCII.NUL;
Set_Env_Value (F_Name'Address, F_Value'Address);
end Set;
-----------
-- Value --
-----------
function Value (Name : String) return String is
use System, System.CRTL;
procedure Get_Env_Value_Ptr (Name, Length, Ptr : Address);
pragma Import (C, Get_Env_Value_Ptr, "__gnat_getenv");
Env_Value_Ptr : aliased Address;
Env_Value_Length : aliased Integer;
F_Name : aliased String (1 .. Name'Length + 1);
begin
F_Name (1 .. Name'Length) := Name;
F_Name (F_Name'Last) := ASCII.NUL;
Get_Env_Value_Ptr
(F_Name'Address, Env_Value_Length'Address, Env_Value_Ptr'Address);
if Env_Value_Ptr = System.Null_Address then
raise Constraint_Error;
end if;
if Env_Value_Length > 0 then
declare
Result : aliased String (1 .. Env_Value_Length);
begin
strncpy (Result'Address, Env_Value_Ptr, size_t (Env_Value_Length));
return Result;
end;
else
return "";
end if;
end Value;
function Value (Name : String; Default : String) return String is
begin
return (if Exists (Name) then Value (Name) else Default);
end Value;
end Ada.Environment_Variables;
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