1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT LIBRARY COMPONENTS                          --
4--                                                                          --
5--                             G N A T . T T Y                              --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--                     Copyright (C) 2002-2019, AdaCore                     --
10--                                                                          --
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.                                     --
17--                                                                          --
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.               --
21--                                                                          --
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/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32with Interfaces.C.Strings; use Interfaces.C.Strings;
33
34package body GNAT.TTY is
35
36   use System;
37
38   procedure Check_TTY (Handle : TTY_Handle);
39   --  Check the validity of Handle. Raise Program_Error if ttys are not
40   --  supported. Raise Constraint_Error if Handle is an invalid handle.
41
42   ------------------
43   -- Allocate_TTY --
44   ------------------
45
46   procedure Allocate_TTY (Handle : out TTY_Handle) is
47      function Internal return System.Address;
48      pragma Import (C, Internal, "__gnat_new_tty");
49
50   begin
51      if not TTY_Supported then
52         raise Program_Error;
53      end if;
54
55      Handle.Handle := Internal;
56   end Allocate_TTY;
57
58   ---------------
59   -- Check_TTY --
60   ---------------
61
62   procedure Check_TTY (Handle : TTY_Handle) is
63   begin
64      if not TTY_Supported then
65         raise Program_Error;
66      elsif Handle.Handle = System.Null_Address then
67         raise Constraint_Error;
68      end if;
69   end Check_TTY;
70
71   ---------------
72   -- Close_TTY --
73   ---------------
74
75   procedure Close_TTY (Handle : in out TTY_Handle) is
76      procedure Internal (Handle : System.Address);
77      pragma Import (C, Internal, "__gnat_close_tty");
78   begin
79      Check_TTY (Handle);
80      Internal (Handle.Handle);
81      Handle.Handle := System.Null_Address;
82   end Close_TTY;
83
84   ---------------
85   -- Reset_TTY --
86   ---------------
87
88   procedure Reset_TTY (Handle : TTY_Handle) is
89      procedure Internal (Handle : System.Address);
90      pragma Import (C, Internal, "__gnat_reset_tty");
91   begin
92      Check_TTY (Handle);
93      Internal (Handle.Handle);
94   end Reset_TTY;
95
96   --------------------
97   -- TTY_Descriptor --
98   --------------------
99
100   function TTY_Descriptor
101     (Handle : TTY_Handle) return GNAT.OS_Lib.File_Descriptor
102   is
103      function Internal
104        (Handle : System.Address) return GNAT.OS_Lib.File_Descriptor;
105      pragma Import (C, Internal, "__gnat_tty_fd");
106   begin
107      Check_TTY (Handle);
108      return Internal (Handle.Handle);
109   end TTY_Descriptor;
110
111   --------------
112   -- TTY_Name --
113   --------------
114
115   function TTY_Name (Handle : TTY_Handle) return String is
116      function Internal (Handle : System.Address) return chars_ptr;
117      pragma Import (C, Internal, "__gnat_tty_name");
118   begin
119      Check_TTY (Handle);
120      return Value (Internal (Handle.Handle));
121   end TTY_Name;
122
123   -------------------
124   -- TTY_Supported --
125   -------------------
126
127   function TTY_Supported return Boolean is
128      function Internal return Integer;
129      pragma Import (C, Internal, "__gnat_tty_supported");
130   begin
131      return Internal /= 0;
132   end TTY_Supported;
133
134end GNAT.TTY;
135