[SOLVED] Calling xmessage from rc.d/local not working

Alfred-Augustus · 11-29-2023, 09:04 AM

Can anyone explain why calling xmessage from rc.d/local does not work?
If I just run the following script manually from a terminal, then xmessage works.

I wrote the following to suspend the laptop when the battery level drops below 10%. Just before that, I want to display a pop-up message in front of the monitor.

Thanks!

Code:

$ cat /etc/rc.d/rc.local 

#!/bin/bash

  /etc/rc.d/rc.low-batt

Code:

$ cat /etc/rc.d/rc.low-batt 

#!/bin/sh

/home/ala/bin/low-batt &

Code:

$ cat /home/ala/bin/low-batt

#!/bin/sh

while sleep 60
do
   battlev=`cat /sys/class/power_supply/BAT0/capacity`

   if test $battlev -lt 10
     then
     xmessage -geometry 300x200+400+200 -title "Battery" \
         -buttons okay:1,quit:0 -default okay \
         "Batt level Low - Suspending" &
         sleep 5
         loginctl suspend
   fi

done

Petri Kaukasoina · 11-29-2023, 09:23 AM

You run xmessage as root, with no DISPLAY set. You could try to change 'xmessage' to 'XAUTHORITY=/home/ala/.Xauthority DISPLAY=:0 xmessage'. It could then work if you had logged in X.

But why do you want to run it as root? Just run it from ~/.xsession or similar, under your uid.

Alfred-Augustus · 11-29-2023, 09:57 AM

Quote:

Originally Posted by Petri Kaukasoina

But why do you want to run it as root? Just run it from ~/.xsession or similar, under your uid.

I didn't really know what I was doing. I was just copying how Thinkfan starts up.

Now, I think I would want to be able to monitor battery and do "loginctl suspend" whether or not a X session has been started.

It would be nice to have that protection as soon as I boot up the laptop.

Tonus · 11-29-2023, 10:55 AM

I guess you could do a test on wich DISPLAY is up and send the message as well with the wall command.

killerhippy · 11-29-2023, 11:04 AM

I use a user systemd service to start a script which uses notify-send.
No need to tell DISPLAY or the like.

File ~/.config/systemd/user/backuphome.service

Quote:

[Unit]
Description=User service to run a backuphome script when the desktop is running
After=multi-user.target

[Service]
Type=oneshot
RemainAfterExit=true
StandardOutput=journal
ExecStart=/usr/local/bin/backup-home-init.sh start
ExecStop=/usr/local/bin/backup-home-init.sh stop
[Install]
WantedBy=default.target

gus3 · 11-29-2023, 06:34 PM

Clearly, he's going with the flow...

michaelk · 11-29-2023, 07:30 PM

Why not run it as a cron job? Since the output is not associated with a display:

* * * * * DISPLAY=:0 /home/ala/bin/low-batt (without the sleep loop)

As posted rc.local output is not associated with a terminal or the desktop. With the DISPLAY=:0 you could also run it via rc.local.

allend · 12-01-2023, 07:51 AM

I used to do something similar using cron. You need to specify the full path name to xmessage in the cron script.