1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . E N V I R O N M E N T _ V A R I A B L E S --
9 -- Copyright (C) 2009-2012, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
33 with Interfaces.C.Strings;
34 with Ada.Unchecked_Deallocation;
36 package body Ada.Environment_Variables is
42 procedure Clear (Name : String) is
43 procedure Clear_Env_Var (Name : System.Address);
44 pragma Import (C, Clear_Env_Var, "__gnat_unsetenv");
46 F_Name : String (1 .. Name'Length + 1);
49 F_Name (1 .. Name'Length) := Name;
50 F_Name (F_Name'Last) := ASCII.NUL;
52 Clear_Env_Var (F_Name'Address);
61 pragma Import (C, Clear_Env, "__gnat_clearenv");
70 function Exists (Name : String) return Boolean is
73 procedure Get_Env_Value_Ptr (Name, Length, Ptr : Address);
74 pragma Import (C, Get_Env_Value_Ptr, "__gnat_getenv");
76 Env_Value_Ptr : aliased Address;
77 Env_Value_Length : aliased Integer;
78 F_Name : aliased String (1 .. Name'Length + 1);
81 F_Name (1 .. Name'Length) := Name;
82 F_Name (F_Name'Last) := ASCII.NUL;
85 (F_Name'Address, Env_Value_Length'Address, Env_Value_Ptr'Address);
87 if Env_Value_Ptr = System.Null_Address then
99 (Process : not null access procedure (Name, Value : String))
101 use Interfaces.C.Strings;
102 type C_String_Array is array (Natural) of aliased chars_ptr;
103 type C_String_Array_Access is access C_String_Array;
105 function Get_Env return C_String_Array_Access;
106 pragma Import (C, Get_Env, "__gnat_environ");
108 type String_Access is access all String;
109 procedure Free is new Ada.Unchecked_Deallocation (String, String_Access);
111 Env_Length : Natural := 0;
112 Env : constant C_String_Array_Access := Get_Env;
115 -- If the environment is null return directly
121 -- First get the number of environment variables
124 exit when Env (Env_Length) = Null_Ptr;
125 Env_Length := Env_Length + 1;
129 Env_Copy : array (1 .. Env_Length) of String_Access;
132 -- Copy the environment
134 for Iterator in 1 .. Env_Length loop
135 Env_Copy (Iterator) := new String'(Value (Env (Iterator - 1)));
138 -- Iterate on the environment copy
140 for Iterator in 1 .. Env_Length loop
142 Current_Var : constant String := Env_Copy (Iterator).all;
143 Value_Index : Natural := Env_Copy (Iterator)'First;
147 exit when Current_Var (Value_Index) = '=';
148 Value_Index := Value_Index + 1;
152 (Current_Var (Current_Var'First .. Value_Index - 1),
153 Current_Var (Value_Index + 1 .. Current_Var'Last));
157 -- Free the copy of the environment
159 for Iterator in 1 .. Env_Length loop
160 Free (Env_Copy (Iterator));
169 procedure Set (Name : String; Value : String) is
170 F_Name : String (1 .. Name'Length + 1);
171 F_Value : String (1 .. Value'Length + 1);
173 procedure Set_Env_Value (Name, Value : System.Address);
174 pragma Import (C, Set_Env_Value, "__gnat_setenv");
177 F_Name (1 .. Name'Length) := Name;
178 F_Name (F_Name'Last) := ASCII.NUL;
180 F_Value (1 .. Value'Length) := Value;
181 F_Value (F_Value'Last) := ASCII.NUL;
183 Set_Env_Value (F_Name'Address, F_Value'Address);
190 function Value (Name : String) return String is
193 procedure Get_Env_Value_Ptr (Name, Length, Ptr : Address);
194 pragma Import (C, Get_Env_Value_Ptr, "__gnat_getenv");
196 procedure Strncpy (Astring_Addr, Cstring : Address; N : Integer);
197 pragma Import (C, Strncpy, "strncpy");
199 Env_Value_Ptr : aliased Address;
200 Env_Value_Length : aliased Integer;
201 F_Name : aliased String (1 .. Name'Length + 1);
204 F_Name (1 .. Name'Length) := Name;
205 F_Name (F_Name'Last) := ASCII.NUL;
208 (F_Name'Address, Env_Value_Length'Address, Env_Value_Ptr'Address);
210 if Env_Value_Ptr = System.Null_Address then
211 raise Constraint_Error;
214 if Env_Value_Length > 0 then
216 Result : aliased String (1 .. Env_Value_Length);
218 Strncpy (Result'Address, Env_Value_Ptr, Env_Value_Length);
226 end Ada.Environment_Variables;