dbus-0.10.13: examples/list-names.hs

{-# LANGUAGE OverloadedStrings #-}

-- Copyright (C) 2009-2011 John Millikin <john@john-millikin.com>
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see <http://www.gnu.org/licenses/>.

module Main (main) where

import           Data.List (sort)
import           DBus
import           DBus.Client

main :: IO ()
main = do
    client <- connectSession

    -- Request a list of connected clients from the bus
    reply <- call_ client (methodCall "/org/freedesktop/DBus" "org.freedesktop.DBus" "ListNames")
        { methodCallDestination = Just "org.freedesktop.DBus"
        }

    -- org.freedesktop.DBus.ListNames returns a single value, which is
    -- a list of names (here represented as [String])
    let Just names = fromVariant (methodReturnBody reply !! 0)

    -- Print each name on a line, sorted so reserved names are below
    -- temporary names.
    mapM_ putStrLn (sort names)