Attached is a patch against udev-008 to send out a D-BUS message when a
device node is added or removed.
Using D-BUS lingo, udev acquires the org.kernel.udev service and sends
out a NodeCreated or NodeDeleted signal on the
org.kernel.udev.NodeMonitor interface. Each signal carries two
parameters: the node in question and the corresponding sysfs path.
[Note: the D-BUS concepts of service, interface, object can be a bit
confusing at first glance]
An example program listening for these messages looks like this
#!/usr/bin/python
import dbus
import gtk
def udev_signal_received(dbus_iface, member, service, object_path, message):
[filename, sysfs_path] = message.get_args_list()
if member=='NodeCreated':
print 'Node %s created for %s'%(filename, sysfs_path)
elif member=='NodeDeleted':
print 'Node %s deleted for %s'%(filename, sysfs_path)
def main():
bus = dbus.Bus(dbus.Bus.TYPE_SYSTEM)
bus.add_signal_receiver(udev_signal_received,
'org.kernel.udev.NodeMonitor', # interface
'org.kernel.udev', # service
'/org/kernel/udev/NodeMonitor') # object
gtk.mainloop()
if __name__ == '__main__':
main()
and this is the output when hot-plugging some usb-storage.
[david@laptop udev-008]$ ~/node_monitor.py
Node /udev/sda created for /block/sda
Node /udev/sda1 created for /block/sda/sda1
Node /udev/sda1 deleted for /block/sda/sda1
Node /udev/sda deleted for /block/sda
The patch requires D-BUS 0.20 or later while the python example program
requires D-BUS from CVS as I only recently applied a patch against the
python bindings.
the older udev.config file is now called udev.rules.
This allows us to better control configuration values, and move away from
the environment variables.
This patch adds a callout config type to udev, so external programs can be
called to get serial numbers or id's that are not available as a sysfs
attribute.
This patch:
1) removes the three database files for just one udevdb.tdb file.
2) adds udevdb_init() and udevdb_exit() functions
3) initializes database now in main() in udev.c.
Please look it over.
mbuesch@freenet.de