I don't think an init script would be appropriate for a per-user script running something in an X session. It is possible to run services just for one user and with the various permissions required for X with systemd but I don't know how to do that with other service managers.

It is possible, i just need to figure it out.

https://unix.stackexchange.com/question … t-like-a-d

dice wrote:

I could try and daemonize it but that would be similar to a while loop script i think?

Not sure what you mean by "daemonize it" but as written the script only runs through once so it can't change the wallpaper unless it is run again at some point.

Why don't you like the while loop? It only runs three very simple shell commands & feh every ten minutes so it's not exactly resource heavy.

I was just trying to think outside the box, explore other ways if there are any.

By daemonize i mean create an init script. Start stop daemon if possible ?

I could try and daemonize it but that would be similar to a while loop script i think?

Not sure what you mean by "daemonize it" but as written the script only runs through once so it can't change the wallpaper unless it is run again at some point.

Why don't you like the while loop? It only runs three very simple shell commands & feh every ten minutes so it's not exactly resource heavy.

EDIT: oops no it wont. I could try and daemonize it but that would be similar to a while loop script i think?

#!/usr/bin/env bash
H=$(date +%H)
if (( 7 <= 10#$H && 10#$H < 13 )); then 
	feh --bg-scale /usr/share/backgrounds/gnome/adwaita-morning.jpg
    echo between 8AM and 1PM
elif (( 13 <= 10#$H && 10#$H < 19 )); then 
	feh --bg-scale /usr/share/backgrounds/gnome/adwaita-day.jpg
    echo between 1PM and 7PM
else
	feh --bg-scale /usr/share/backgrounds/gnome/adwaita-night.jpg
    echo night
fi

I give in, looks like a while loop is the way to go, below is a variant. Hoping this works...

#!/usr/bin/env bash

get_wall () {

H=$(date +%H)
if (( 7 <= 10#$H && 10#$H < 13 )); then 
	feh --bg-scale /usr/share/backgrounds/gnome/adwaita-morning.jpg
    echo between 8AM and 1PM
elif (( 13 <= 10#$H && 10#$H < 19 )); then 
	feh --bg-scale /usr/share/backgrounds/gnome/adwaita-day.jpg
    echo between 1PM and 7PM
else
	feh --bg-scale /usr/share/backgrounds/gnome/adwaita-night.jpg
    echo night
fi

}

while true; do
  get_wall;
  sleep 600;
done

I tried to make something that wasnt in a while loop and have come up with the below, i would like to add in a 3rd command so it is 3 times of day (morn, day, night) but cant figure that out.

#!/usr/bin/env bash

DATE=$(date +%p)
DATE2=$(date +%p)
MORNING="AM"
NIGHT="PM"

if [[ "$DATE" == "$MORNING" ]] ; then
	feh --bg-scale /usr/share/backgrounds/gnome/adwaita-morning.jpg
elif [[ "$DATE2" == "$NIGHT" ]] ; then
        feh --bg-scale /usr/share/backgrounds/gnome/adwaita-night.jpg
fi

what do you think of below script?

I don't think that will work because all three jobs will be run at the same time.

You could use a case statement to set the wallpaper according to the time and check every 10 minutes with a while loop:

#!/bin/sh

while true
do
   case $(date +%H) in
      [0-9]|1[0-1]) time=morning;;
      1[2-8]) time=day;;
      19|2[0-3]) time=night;;
   esac
   feh --bg-scale /usr/share/backgrounds/gnome/adwaita-$time.jpg
   sleep 600
done

No need for at at all

And to keep this post on topic I would recommend checking the POSIX specification for more details on the command:

https://pubs.opengroup.org/onlinepubs/9 … es/at.html

The "APPLICATION USAGE" section at the end is particularly useful.

EDIT: moved sleep inside the while loop so that the wallpaper is set immediately.

I was referring to this part of the man page

Yes, it does seem to be somewhat contradictory, not sure why

If you run it without -f then it accepts input from STDIN:

$ at now + 1 minute        
warning: commands will be executed using /bin/sh
at> DISPLAY=:0 /usr/bin/x-terminal-emulator
at> <EOT>
job 11 at Sat Dec 12 19:52:00 2020
$

(<ctrl>+d exits the prompt.)

EDIT: or with a here string:

$ at now + 1 minute <<<'DISPLAY=:0 /usr/bin/x-terminal-emulator'
warning: commands will be executed using /bin/sh
job 13 at Sat Dec 12 19:58:00 2020
~$

A here document also works.

Your example worked. I was not putting the command inside a file. Isn't there a way to run the command from the command line?
This works:

at now + 1 minute -f testfile

This does not work:

at now + 1 minute echo "hello"

dice wrote:

but this below would not work as a line not broken.

echo 'DISPLAY=:0 $HOME/bin/fehrand' > ~/test
at now + 1 minute -f ~/test

I don't think $HOME will be understood unless you specify it (replace $user with the actual username):

echo 'DISPLAY=:0 HOME=/home/$user $HOME/bin/fehrand' > ~/test
at now + 1 minute -f ~/test

Or just call the full path to the script, which would be simpler.

im just not using full paths publicly on the forum.

but this below would not work as a line not broken.

echo 'DISPLAY=:0 $HOME/bin/fehrand' > ~/test
at now + 1 minute -f ~/test

I don't think $HOME will be understood unless you specify it (replace $user with the actual username):

echo 'DISPLAY=:0 HOME=/home/$user $HOME/bin/fehrand' > ~/test
at now + 1 minute -f ~/test

Or just call the full path to the script, which would be simpler.

I cant understand how the command is laid out though. very strange if you ask me.

This below worked for a feh command.

echo 'DISPLAY=:0 $HOME/bin/fehrand' > ~/test
at now + 1 minute -f ~/test

but this below would not work as a line not broken.

echo 'DISPLAY=:0 $HOME/bin/fehrand' > ~/test at now + 1 minute -f ~/test

home env variable added to the code quotes.

contents of fehrand

#!/bin/bash

feh --randomize --bg-scale /usr/share/backgrounds/*

~ $ > at now + 1 minute -f /usr/local/bin/st

The -f switch causes the command to be read from a file, which you have specified as /usr/local/bin/st.

Try this instead:

echo 'DISPLAY=:0 /usr/local/bin/st' > ~/test
at now + 1 minute -f ~/test

^ That works for me. Note that any environmental variables are not passed to the command so they must be specified explicitly.

Actually the man page says:

So try

at -t 12121600 -f ~/test

HTH

EDIT: that example runs the command on 2020-12-12 at 16:00.