用python接收dbus信号

Posted 2023-04-14

【中文标题】用python接收dbus信号

【英文标题】：receive dbus signals with python

【发布时间】：2016-09-16 03:56:43

【问题描述】：

我正在尝试制作一个 python 脚本，它通过 dbus 监听信号并将它们存储在一个文件中，因为我需要接收信号的服务会发送一个始终在变化的哈希密码。 我已经阅读了这些manuals，但由于我不了解 python，我需要任何帮助。

import sys
import traceback
import gobject
import dbus
import dbus.mainloop.glib

def handle_reply(msg):
print msg

def handle_error(e):
print str(e)

def emit_signal():
#call the emitHelloSignal method 
object.emitHelloSignal(dbus_interface="com.example.TestService")
                      #reply_handler = handle_reply, error_handler = handle_error)
# exit after waiting a short time for the signal
gobject.timeout_add(2000, loop.quit)

if sys.argv[1:] == ['--exit-service']:
  object.Exit(dbus_interface='com.example.TestService')

return False

def hello_signal_handler(hello_string):
print ("Received signal (by connecting using remote object) and it says: "
       + hello_string)

def catchall_signal_handler(*args, **kwargs):
print ("Caught signal (in catchall handler) "
       + kwargs['dbus_interface'] + "." + kwargs['member'])
for arg in args:
    print "        " + str(arg)

def catchall_hello_signals_handler(hello_string):
print "Received a hello signal and it says " + hello_string

def catchall_testservice_interface_handler(hello_string, dbus_message):
print "com.example.TestService interface says " + hello_string + " when it    sent signal " + dbus_message.get_member()


if __name__ == '__main__':
dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)

bus = dbus.SessionBus()
try:
    object  =  bus.get_object("com.example.TestService","/com/example/TestService/object")

    object.connect_to_signal("HelloSignal", hello_signal_handler,    dbus_interface="com.example.TestService", arg0="Hello")
    except dbus.DBusException:
    traceback.print_exc()
    print usage
    sys.exit(1)

#lets make a catchall
bus.add_signal_receiver(catchall_signal_handler,  interface_keyword='dbus_interface', member_keyword='member')

bus.add_signal_receiver(catchall_hello_signals_handler, dbus_interface =  "com.example.TestService", signal_name = "HelloSignal")

bus.add_signal_receiver(catchall_testservice_interface_handler,   dbus_interface = "com.example.TestService", message_keyword='dbus_message')

# Tell the remote object to emit the signal after a short delay
gobject.timeout_add(2000, emit_signal)

loop = gobject.MainLoop()
loop.run()

感谢任何帮助

【问题讨论】：

现有的工作示例可以基于您的代码：github.com/stylesuxx/python-dbus-examples

【参考方案1】：

您可以使用 dbus-monitor 来检查信号是什么样的

dbus-monitor --system "type='signal',sender='org.bluez'"

下面是我接收信号的python3示例代码：

import dbus
from gi.repository import GLib
from dbus.mainloop.glib import DBusGMainLoop

def signal_handler(*args, **kwargs):
    for i, arg in enumerate(args):
        print("arg:%d        %s" % (i, str(arg)))
    print('kwargs:')
    print(kwargs)
    print('---end----')

DBusGMainLoop(set_as_default=True)
bus = dbus.SystemBus()
#register your signal callback
bus.add_signal_receiver(signal_handler,
                        bus_name='org.bluez',
                        interface_keyword='interface',
                        member_keyword='member',
                        path_keyword='path',
                        message_keyword='msg')

loop = GLib.MainLoop()
loop.run()

修改 bus_name/sender 以适合您的情况