can i use udev rules to send a dbus signal

hi all

I met a problem . Does anybody help me ?
I wrote a udeve rules for ntfs filesystem mount , and i want to using dbus-send to send a dbus signal .But it seems it can not work . When I debuge, i saw /var/log/message said it send ok. But , in fact , it can not work. Does anybody know this issue?

PS: When exec udev rules, it should be root , and i am using a normal user to debug and see result.

[fan@fc13 rules.d]$ cat 10-media-by-label-auto-mount.rules |grep -v ^# KERNEL!="sd[b-z][0-9]", GOTO="media_by_label_auto_mount_end" IMPORT{program}="/sbin/blkid -o udev -p %N" ENV{dir_name}="usb-%k"
ENV{DISPLAY}=":0.0"

ACTION="add", ENV{ID_FS_TYPE}="ntfs", ENV{mount_options}="relatime,utf8,gid0,umask2", RUN+="/bin/mkdir -p /media/%E{dir_name}", RUN+="/bin/mount -t ntfs-3g -o $env{mount_options} /dev/%k /media/%E{dir_name}", RUN+="/usr/bin/nautilus --no-desktop /media/%E{dir_name}", RUN+="/bin/dbus-send --session --type=signal / com.zhou.dbustest.sayhelloworld"

ACTION="remove", RUN+="/bin/umount -l /media/%E{dir_name}", RUN+="/bin/rmdir /media/%E{dir_name}" LABEL="media_by_label_auto_mount_end"
[fan@fc13 rules.d]$

Hello shaoning,

shaoning [2010-12-08 16:06 +0800]:

This isn't going to work like this. udev rules are executed as root, so this tries to start nautilus and dbus-send as root, neither of which makes sense. root doesn't have a session d-bus running, so the dbus-send will just shout into the void.

udev isn't meant to run stuff for users, that needs to happen in the user's session. It's possible to use su, read xauth cookies etc. to pick the first X.org session and run stuff there, but all these are horrible, horrible hacks.

If you are already using GNOME components, what's wrong with using udisks and running nautilus as the automount daemon? If you can't do that in your setup, you could also use a lightweight automount daemon like [1].

Martin

[1] http://www.piware.de/2010/09/simple-udisks-based-automount-daemon/

Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)