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ada_libfswatch/examples/basic.adb
Nicolas Setton 01c9e3ebbd License under the GPLv3 + Runtime exception
Since this is a library.
2020-10-16 14:50:00 +01:00

145 lines
4.8 KiB
Ada

------------------------------------------------------------------------------
-- --
-- Ada_Libfswatch --
-- --
-- Copyright (C) 2020, AdaCore --
-- --
-- This library is free software; you can redistribute it and/or modify it --
-- under terms of the GNU General Public License as published by the Free --
-- Software Foundation; either version 3, or (at your option) any later --
-- version. This library is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHAN- --
-- TABILITY 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/>. --
-- --
------------------------------------------------------------------------------
-- Demonstrator for the low-level use of Libfswatch
pragma Ada_2020;
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Unchecked_Conversion;
with Interfaces.C; use Interfaces.C;
with Interfaces.C.Strings;
with libfswatch_h; use libfswatch_h;
with libfswatch_types_h; use libfswatch_types_h;
with cmonitor_h;
with cevent_h; use cevent_h;
with System; use System;
with Libfswatch; use Libfswatch;
with Libfswatch.Conversions; use Libfswatch.Conversions;
procedure Basic is
Init : int;
Status : FSW_STATUS;
Session : FSW_HANDLE;
task Stop_After_10_Seconds;
-- Stop the session after 10 seconds.
procedure Callback
(arg1 : access constant fsw_cevent;
arg2 : unsigned;
arg3 : System.Address) with Convention => C;
-- The function which is called when an event arrives
--------------
-- Callback --
--------------
procedure Callback
(arg1 : access constant fsw_cevent;
arg2 : unsigned;
arg3 : System.Address)
is
Events : Event_Vectors.Vector;
begin
-- Convert the C array of events to Ada structures
Events := To_Ada (arg1, arg2);
-- Simple prints of the events we receive
for E of Events loop
Put_Line (Event_Image (E));
end loop;
end Callback;
---------------------------
-- Stop_After_10_Seconds --
---------------------------
task body Stop_After_10_Seconds is
begin
-- Wait 10 seconds
delay 10.0;
-- Stop the monitoring
Status := fsw_stop_monitor (Session);
if Status /= 0 then
Put_Line ("Error when stopping the session");
end if;
end Stop_After_10_Seconds;
begin
--------------------
-- Initialization --
--------------------
-- Initialize the library
Init := libfswatch_h.fsw_init_library;
if Init /= 0 then
Put_Line ("Error when initializing the library");
return;
end if;
-- Initialize the session
Session := fsw_init_session (cmonitor_h.system_default_monitor_type);
if Session = null then
Put_Line ("Error when initializing the session");
return;
end if;
----------------
-- Monitoring --
----------------
-- Add the monitoring of the current directory
Status := fsw_add_path (Session, Interfaces.C.Strings.New_String ("."));
if Status /= 0 then
Put_Line ("Error when adding path");
return;
end if;
-- Set a callback to be called whenever an event arrives on any
-- of the paths being monitored.
Status := fsw_set_callback
(Session, Callback'Unrestricted_Access, System.Null_Address);
if Status /= 0 then
Put_Line ("Error when setting callback");
return;
end if;
Put_Line ("Listening to events...");
New_Line;
-- Start the actual monitoring. This call is blocking - it only returns
-- when the task calls fsw_stop_monitor.
Status := fsw_start_monitor (Session);
if Status /= 0 then
Put_Line ("Error when starting monitor");
return;
end if;
Put_Line ("Done.");
end Basic;