Question

4

Problem with `notify-send`

rated 0 times [ 4] [ 0] / answers: 1 / hits: 4177 / 2 Years ago, sun, july 3, 2022, 2:34:25

I have been working in a script to change audio output when you (dis)connect am HDMI screen/TV. Basically it uses UDEV to check any change in the connection and acts accordingly.

Everything works fine except one thing: I can't use notify-send to warn about the change. I use the following code (output is just a wrapper to subprocess.check_output):

output("sudo -u {0} notify-send "{1}" "{2}"".format(user, title, message))

but I don get any notification at all.

What is really odd is that if I run hdmi_sound_toggle (as a normal user or with sudo) everything works just fine!

So what could be the problem here? There is any better way to present a notification than with notify-send?

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1 Year ago

answered 2 Years ago issfullus · Accepted Answer

The notify-send has trouble putting notifications on a user's screen when called from a script run by root or another user.

You should use:

output("export DISPLAY=:0; sudo -u {0} notify-send "{1}" "{2}"".format(user, title, message))

So, use:

export DISPLAY=:0

Normally a user is on display :0, but to be sure, you can find which display a user is on using who command as follow:

who | grep -m1 ^username.*( | awk '{print $5}' | sed 's/[(|)]//g'

This worked for me in this script.

See also: Can I launch a graphical program on another user's desktop as root?