我如何在Linux和Python中监听“usb设备插入”事件?

[英]How can I listen for 'usb device inserted' events in Linux, in Python?


I'd like to write a Python script for Amarok in Linux to automatically copy the stackoverflow podcast to my player. When I plug in the player, it would mount the drive, copy any pending podcasts, and eject the player. How can I listen for the "plugged in" event? I have looked through hald but couldn't find a good example.

我想为Amarok在Linux中编写一个Python脚本,将stackoverflow播客自动复制到我的播放器中。当我插入播放器时,它会挂载驱动器,复制任何挂起的播客,并弹出播放器。我怎样才能听到“插入”事件呢?我查了哈德的资料,但找不到好的例子。

4 个解决方案

#1


51  

Update: As said in comments, Hal is not supported in recent distributions, the standard now is udev, Here is a small example that makes use of glib loop and udev, I keep the Hal version for historical reasons.

更新:正如评论中所说,Hal在最近的发行版中不受支持,现在的标准是udev,这里有一个使用glib循环和udev的小例子,出于历史原因,我保留了Hal版本。

This is basically the example in the pyudev documentation, adapted to work with older versions, and with the glib loop, notice that the filter should be customized for your specific needing:

这基本上是pyudev文档中的示例,适用于旧版本,使用glib循环时,请注意过滤器应该根据您的具体需求进行定制:

import glib

from pyudev import Context, Monitor

try:
    from pyudev.glib import MonitorObserver

    def device_event(observer, device):
        print 'event {0} on device {1}'.format(device.action, device)
except:
    from pyudev.glib import GUDevMonitorObserver as MonitorObserver

    def device_event(observer, action, device):
        print 'event {0} on device {1}'.format(action, device)

context = Context()
monitor = Monitor.from_netlink(context)

monitor.filter_by(subsystem='usb')
observer = MonitorObserver(monitor)

observer.connect('device-event', device_event)
monitor.start()

glib.MainLoop().run()

Old version with Hal and d-bus:

旧版本的Hal和d-bus:

You can use D-Bus bindings and listen to DeviceAdded and DeviceRemoved signals. You will have to check the capabilities of the Added device in order to select the storage devices only.

您可以使用D-Bus绑定并侦听deviceadd和DeviceRemoved信号。您必须检查添加设备的功能,以便只选择存储设备。

Here is a small example, you can remove the comments and try it.

这里有一个小例子,您可以删除注释并尝试它。

import dbus
import gobject

class DeviceAddedListener:
    def __init__(self):

You need to connect to Hal Manager using the System Bus.

您需要使用系统总线连接到Hal Manager。

        self.bus = dbus.SystemBus()
        self.hal_manager_obj = self.bus.get_object(
                                              "org.freedesktop.Hal", 
                                              "/org/freedesktop/Hal/Manager")
        self.hal_manager = dbus.Interface(self.hal_manager_obj,
                                          "org.freedesktop.Hal.Manager")

And you need to connect a listener to the signals you are interested on, in this case DeviceAdded.

你需要连接一个监听器到你感兴趣的信号,在这个例子中是deviceadd。

        self.hal_manager.connect_to_signal("DeviceAdded", self._filter)

I'm using a filter based on capabilities. It will accept any volume and will call do_something with if, you can read Hal documentation to find the more suitable queries for your needs, or more information about the properties of the Hal devices.

我在使用基于功能的过滤器。它将接受任何卷,并将调用do_something与if,您可以阅读Hal文档来查找更适合您的需求的查询,或更多关于Hal设备属性的信息。

    def _filter(self, udi):
        device_obj = self.bus.get_object ("org.freedesktop.Hal", udi)
        device = dbus.Interface(device_obj, "org.freedesktop.Hal.Device")

        if device.QueryCapability("volume"):
            return self.do_something(device)

Example function that shows some information about the volume:

显示有关卷的一些信息的示例函数:

     def do_something(self, volume):
        device_file = volume.GetProperty("block.device")
        label = volume.GetProperty("volume.label")
        fstype = volume.GetProperty("volume.fstype")
        mounted = volume.GetProperty("volume.is_mounted")
        mount_point = volume.GetProperty("volume.mount_point")
        try:
            size = volume.GetProperty("volume.size")
        except:
            size = 0

        print "New storage device detectec:"
        print "  device_file: %s" % device_file
        print "  label: %s" % label
        print "  fstype: %s" % fstype
        if mounted:
            print "  mount_point: %s" % mount_point
        else:
            print "  not mounted"
        print "  size: %s (%.2fGB)" % (size, float(size) / 1024**3)

if __name__ == '__main__':
    from dbus.mainloop.glib import DBusGMainLoop
    DBusGMainLoop(set_as_default=True)
    loop = gobject.MainLoop()
    DeviceAddedListener()
    loop.run()

#2


7  

I haven't tried writing such a program myself, however I've just looked at the following two links (thanks Google!), which I think will be of help:

我自己还没有尝试过写这样的程序,但是我只看了下面两个链接(谢谢谷歌!)

  • dbus-python tutorial (which talks about how to use Python to access D-Bus)
  • dbus-python教程(讨论如何使用Python访问D-Bus)
  • HAL 0.5.10 Specification (which talks about how HAL publishes events to D-Bus)
  • HAL 0.5.10规范(讨论HAL如何将事件发布到D-Bus)

In particular, read about the org.freedesktop.Hal.Manager interface, and its DeviceAdded and DeviceRemoved events. :-)

特别是,阅读关于org.freedesktop.Hal.Manager接口及其deviceadd和DeviceRemoved事件的文章。:-)

Hope this helps!

希望这可以帮助!

#3


4  

I think D-Bus would work as Chris mentioned, but if you're using KDE4, you might use the Solid framework in a manner similar to the KDE4 "New Device Notifier" applet.

我认为D-Bus会像Chris提到的那样工作,但是如果您使用KDE4,您可能会使用与KDE4“新设备通知器”applet类似的实体框架。

The C++ source for that applet is here, which shows how to use Solid to detect new devices. Use PyKDE4 for Python bindings to these libraries, as shown here.

这个applet的c++源代码在这里,它展示了如何使用Solid来检测新设备。将PyKDE4用于这些库的Python绑定,如图所示。

#4


2  

Here is a solution in 5 lines.

这是5行解。

import pyudev

context = pyudev.Context()
monitor = pyudev.Monitor.from_netlink(context)
monitor.filter_by(subsystem='usb')

for device in iter(monitor.poll, None):
    if device.action == 'add':
        print('{} connected'.format(device))
        # do something very interesting here.

Save this to a file say usb_monitor.py, run python monitor.py. Plug any usb and it will print device details

保存到一个文件,比如usb_monitor。py,运行python monitor.py。插入任何usb,它将打印设备细节

→ python usb_monitor.py 
Device('/sys/devices/pci0000:00/0000:00:14.0/usb1/1-6/1-6:1.0') connected
Device('/sys/devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1:1.0') connected

Tested on Python 3.5 with pyudev==0.21.0.

在Python 3.5上测试,pyudev= 0.21.0。


注意!

本站翻译的文章,版权归属于本站,未经许可禁止转摘,转摘请注明本文地址:https://www.itdaan.com/blog/2009/01/22/4f559579d13744914108d0b1fd5f9feb.html



 
粤ICP备14056181号  © 2014-2020 ITdaan.com