Here we get the ability to query with the name of the node instead of
the device path. It uses a linear search over the whole database.
kay@pim:~/src/udev.kay$ ./udev -q path -n video/webcam0
/class/video4linux/video0
New version, with better function return codes for error handling.
On Thu, Jan 15, 2004 at 05:14:16AM +0100, Kay Sievers wrote:
> On Wed, Jan 14, 2004 at 01:10:43PM -0800, Greg KH wrote:
> > On Wed, Jan 14, 2004 at 02:34:26PM -0600, Clay Haapala wrote:
> > > On Wed, 14 Jan 2004, Chris Friesen spake thusly:
> > > >
> > > > Maybe for ones with a matching rule, you could print something like:
> > > >
> > > >
> > > Is the act of printing/syslogging a rule in an of itself?
> >
> > No, as currently the only way stuff ends up in the syslog is if
> > DEBUG=true is used on the build line.
> >
> > But it's sounding like we might want to change that... :)
>
> How about this in the syslog after connect/disconnect?
>
> Jan 15 05:07:45 pim udev[28007]: configured rule in '/etc/udev/udev.rules' at line 17 applied, 'video*' becomes 'video/webcam%n'
> Jan 15 05:07:45 pim udev[28007]: creating device node '/udev/video/webcam0'
> Jan 15 05:07:47 pim udev[28015]: removing device node '/udev/video/webcam0'
Here is a slightly better version. I've created a logging.h file and
moved the debug macros from udev.h in there.
If you type:
'make' - you will get a binary that prints one or two lines to syslog
if a device node is created or deleted
'make LOG=false' - you get a binary that prints asolutely nothing
'make DEBUG=true' - the same as today, it will print all debug lines
This patch improves the user options for udev.
It is possible now to query for the name, the symlinks or owner/group.
If asked for the name of the node we are able to prepend the udev_root
with the -r option.
SAMPLE:
kay@pim:~/src/udev.test$ ./udev -V
udev, version 012_bk
kay@pim:~/src/udev.test$ ./udev -h
Usage: [-qrVh]
-q <name> query database for the specified value
-p <path> device path used for query
-r print udev root
-V print udev version
-h print this help text
kay@pim:~/src/udev.test$ ./udev -r
/udev/
kay@pim:~/src/udev.test$ ./udev -q name -p /class/video4linux/video0
video/webcam0
kay@pim:~/src/udev.test$ ./udev -q symlink -p /class/video4linux/video0
camera0 kamera0
kay@pim:~/src/udev.test$ ./udev -q owner -p /class/video4linux/video0
501
kay@pim:~/src/udev.test$ ./udev -r -q name -p /class/video4linux/video0
/udev/video/webcam0
Hello,
without this patch:
wolf@duel:/tmp/ud/udev-012>gcc -v
Reading specs from /usr/lib/gcc-lib/i386-slackware-linux/2.95.3/specs
gcc version 2.95.3 20010315 (release)
cannot compile udev.
On Wed, Dec 31, 2003 at 11:24:53AM -0800, Greg KH wrote:
> > There should be a possibility to tell udev not to create a device node.
> >
> > device-mapper: Usually set up by libdevmapper (or EVMS tools) which
> > creates the device node on its own under /dev/mapper/<name>.
> >
> > With udev a second device is created named /dev/dm-<minor> which is not
> > really needed.
>
> Good point. Ok, I'll agree with you. Care to make up a patch for this
> kind of feature?
Yes, I can try.
There was no way to tell not to do anything so I created one. Errors
are signalled via negative return values, so I thought that a positive,
non-zero one could mean to ignore the device. I don't like it but
perhaps you have a better solution.
This one is nothing important, just add some quotes to be more consistent
with the rest and make sure that the return value is positive (since the
error return values are negative). Hmm?
Here is a slightly better version that prints the usage if a unknown option is given:
kay@pim:~/src/udev.kay$ ./udev -x
./udev: invalid option -- x
Usage: [-qrVh]
-q arg query database
-r print udev root
-V print udev version
-h print this help text
> Here is a patch that makes it possible to call udev with options on the command line.
> Valid options are for now:
>
> -V for the udev version:
> kay@pim:~/src/udev.kay$ ./udev -V
> udev, version 011_bk
>
> -r for the udev root:
> kay@pim:~/src/udev.kay$ ./udev -r
> /udev/
>
> -q to query the database with the sysfs path for the name of the node:
> kay@pim:~/src/udev.kay$ ./udev -q /class/video4linux/video0
> test/video/webcam0
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.
