I am having a strange problem while doing ssh. I am not sure where the term Unmatched ` is coming from. What I need to do is run script that logs information of what I am doing on the terminal to text file. After ssh -
Sun Microsystems Inc. SunOS 5.8 Generic Patch October 2001
This is /etc/motd, last updated 3 Feb 2003.
To learn about the UCS system and other aspects of computing at UL-Lafayette
visit our home page http://helpdesk.louisiana.edu/ .
For more information about system use, contact the Help Desk, Stephens
Hall, Room 201, 482-5516 (x25516), during normal UL office hours; or send
e-mail to helpdesk#louisiana.edu.
ATTENTION:
Unsecure Telnet and FTP will be turned off soon.
Please make arrange to use ssh or sftp.
Putty(telnet) and WinSCP(ftp) would be a good replacement.
Unmatched `
d13.ucs.louisiana.edu% bash
bash-2.04$ script -a myInformation.txt
Script started, file is myInformation.txt
Unmatched `
d13.ucs.louisiana.edu%
When I tried to start the script with name myInformation.txt, you can see the message I am getting - Script started, file is myInformation.txt. But again I am getting that message Unmatched ` and is coming out of bash, as you can notice. What is the problem ? Any insights suggested would be very great.
Note: file with name myInformation.txt is being created but nothing goes in to it. As I have even tried running certain commands like ls and then exited the script with ctrl+d. But when I open the file, nothing is there.
.cshrc
`# #(#)cshrc 1.11 89/11/29 SMI
if ( `uname -s` == "Linux") then
# /etc/csh.{cshrc,login} set the csh and tcsh environments for Linux
# We just modify a few here:
set history=20 savehist=20
exit 0
endif
umask 027
# add here additional directories
set lpath = ()
set path = (~ ~/bin $lpath /usr/local/bin /usr/ccs/bin /usr/dt/bin /usr/openwin/bin /usr/bin /usr/sbin /usr/ucb .)
unset lpath
set noclobber
# Comment out the next line if you WANT core dumps (to debug via dbx,adb,gdb...)
limit coredumpsize 0
# An alternative to the above is to symlink ~/core to /dev/null ....
# Note that a core file can put you over quota, necessitating a command-line
# login [pick from the CDE Options menu] to be able to remove it.
if ( $?prompt == 0) exit
# Put here cmds suitable just for interactive c-shells
set history=20 savehist=20 time=10 autologout=28800
#set ignoreeof
set filec
set notify
#alias ls 'ls -F'
alias mail mailx
alias nissql /pkgs2/mysql/bin/mysql -h calvados.ucs.louisiana.edu -u cs4601d -p cs4601_d
.login
# #(#)local.login 1.5 98/10/03 SMI
if (`uname -s` == "Linux") then
exit 0
endif
if (! $?DT ) then
# Insert HERE and commands that are interactive, or alter the terminal
# characteristics. Thus, they will be bypassed if you start CDE and your
# .dtprofile invokes .login. Also remember /etc/.login is run first
# by non-CDE logins, and already sets some terminal characteristics.
# -- jpd#usl.edu
stty -istrip
endif
# environment variables
#setenv EXINIT 'set sh=/bin/csh sw=4 ai report=2'
#setenv MORE '-c'
#setenv PRINTER lw
setenv RNINIT '-I -e -m -S -i=11 -N -/ -h +hdate +hlines +hfrom -hdate-'
setenv LESS mQ
#setenv PRDEPT nnnn
setenv PAGER /usr/local/bin/less
#setenv EDITOR /usr/local/bin/emacs
setenv MANPATH /usr/local/man:/usr/local/perl/man:/usr/dt/man:/usr/openwin/man:/usr/man
#setenv AB2_DEFAULTSERVER http://pineau.ucs.louisiana.edu:8888/
setenv AB2_DEFAULTSERVER http://docs.sun.com:80/
setenv H_SPELL /dev/null
#
# if possible, start the windows system. Give user a chance to bail out
# To enable attempting openwin, set try_openwin=1 in the line below:
set try_openwin=0
if ( `tty` == "/dev/console" && $try_openwin) then
if ( "$TERM" == "sun" || "$TERM" == "sun-color" || "$TERM" == "AT386" ) then
if ( ${?OPENWINHOME} == 0 ) then
setenv OPENWINHOME /usr/openwin
endif
echo ""
echo -n "Starting OpenWindows in 5 seconds (type Control-C to interrupt)"
sleep 5
echo ""
$OPENWINHOME/bin/openwin
clear # get rid of annoying cursor rectangle
echo -n "Automatically logging out (type Control-C to interrupt)"
sleep 5
logout # logout after leaving windows system
endif
endif
unset try_openwin
The extra ` seems to be right there in the very beginning of your .cshrc.
...except of course if you are running bash as you say. What's the output of ps?
Related
In Windows when I double-click a Batch script, it will automatically open a terminal window and show me what's happening. If I were to double-click a bash script in Linux, a terminal window does not open to show me what is happening; it runs in the background. I have seen that one can use one script to launch another script in a new terminal window with x-terminal-emulator -e "./script.sh", but is there any bash command I can put into the same (one) script.sh so that it will open a terminal and show me what's happening (or if I need to answer y/n questions)?
You can do something similar to what Slax
developers do in their bootinst.sh:
#!/usr/bin/env sh
#
# If you see this file in a text editor instead of getting it executed,
# then it is missing executable permissions (chmod). You can try to set
# exec permissions for this file by using: chmod a+x bootinst.sh
#
# Scrolling down will reveal the actual code of this script.
#
# if we're running this from X, re-run the script in konsole or xterm
if [ "$DISPLAY" != "" ]; then
if [ "$1" != "--rex" -a "$2" != "--rex" ]; then
konsole --nofork -e /bin/sh $0 --rex 2>/dev/null || xterm -e /bin/sh $0 --rex 2>/dev/null || /bin/sh $0 --rex 2>/dev/null
exit
fi
fi
# put contents of your script here
echo hi
# do not close the terminal immediately, let user look at the results
echo "Press Enter..."
read junk
This script would run correctly both when started in graphical
environment and in tty. It tries to restart the script inside
konsole and xterm and but if it doesn't find neither of them it
will simply run in the background.
on my raspberry pi (raspbian running) I would like to have the current desktop switched to desktop n#0 after 5 minutes of idle system (no mouse or keyboard action), through wmctrl -s 0 and xprintidle for idle time checking.
Please keep in mind I'm no expert...
I tried 2 different ways, none of them working and I was wondering which one of them is the best way to do have the job done:
bash script and crontab
I wrote a simple script which checks if xprintidle is greater than a previously set $IDLE_TIME, than it switches desktops (saved in /usr/local/bin/switchDesktop0OnIdle):
#!/bin/bash
# 5 minutes in ms
IDLE_TIME=$((5*60*1000))
# Sequence to execute when timeout triggers.
trigger_cmd() {
wmctrl -s 0
}
sleep_time=$IDLE_TIME
triggered=false
while sleep $(((sleep_time+999)/1000)); do
idle=$(xprintidle)
if [ $idle -ge $IDLE_TIME ]; then
if ! $triggered; then
trigger_cmd
triggered=true
sleep_time=$IDLE_TIME
fi
else
triggered=false
# Give 100 ms buffer to avoid frantic loops shortly before triggers.
sleep_time=$((IDLE_TIME-idle+100))
fi
done
script itself works.
Then I added it to crontab (crontab -e) for have it run every 6 minutes
*/6 * * * * * sudo /usr/local/bin/switchDesktop0OnIdle
not sure sudo is necessary or not.
Anyway It doesn't work: googling around I understood that crontab runs in its own environment with its own variables. Even though I don't remember how to access this environment (oops) I do remember that I get these 2 errors running the script in it (which correctly works in "normal" shell)
could not open display (is it important ?)
bla bla -ge error, unary operator expected or similar: basically xprintidle doesn't work in this environment a gives back an empty value
What am I missing ?
infinite-while bash script running as daemon
second method I tried to set up a script with an internal infinite-while checking if xprintidle is greater then 5 minutes. In this case desktop is switched (less elegant?). Saved also in /usr/local/bin/switchDesktop0OnIdle
#!/bin/bash
triggered=false
while :
do
if [ `xprintidle` -ge 300000 ]; then
if [ triggered == false ]
wmctrl -s 0
triggered = true
fi
else
triggered = false
fi
fi
done
again the script itself works.
I tried to create a daemon in /etc/init.d/switchDesktop0OnIdle (really not an expert here, modified an existing one)
#! /bin/sh
# /etc/init.d/switchDesktop0OnIdle
### BEGIN INIT INFO
# Provides: switchDesktop0OnIdle
# Required-Start: $all
# Required-Stop: $all
# Should-Start:
# Should-Stop:
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description:
# Description:
### END INIT INFO
DAEMON=/usr/local/bin/switchDesktop0OnIdle
NAME=switchDesktop0OnIdle
test -x $DAEMON || exit 0
case "$1" in
start)
echo -n "Starting daemon: "
start-stop-daemon --start --exec $DAEMON
echo "switchDesktop0OnIdle."
;;
stop)
echo -n "Shutting down daemon:"
start-stop-daemon --stop --oknodo --retry 30 --exec $DAEMON
echo "switchDesktop0OnIdle."
;;
restart)
echo -n "Restarting daemon: "
start-stop-daemon --stop --oknodo --retry 30 --exec $DAEMON
start-stop-daemon --start --exec $DAEMON
echo "switchDesktop0OnIdle."
;;
*)
echo "Usage: $0 {start|stop|restart}"
exit 1
esac
exit 0
I set it up
sudo update-rc.d switchDesktop0OnIdle defaults
and
sudo service switchDesktop0OnIdle start
(necessary?)
...and nothing happens...
also I don't find the process with ps -ef | grep switchDesktop0OnIdle but it seems running with sudo service switchDesktop0OnIdle status
can anyone please help?
thank you
Giuseppe
As you suspected, the issue is that when you run your scripts from init or from cron, they are not running within the GUI environment you want them to control. In principle, a Linux system can have multiple X environments running. When you are using one, there are environment variables that direct the executables you are using to the environment you are in.
There are two parts to the solution: your scripts have to know which environment they are acting on, and they have to have authorization to interact with that environment.
You almost certainly are using a DISPLAY value of ":0", so export DISPLAY=:0 at the beginning of your script will handle the first part of the problem. (It might be ":0.0", which is effectively equivalent).
Authorization is a bit more complex. X can be set up to do authorization in different ways, but the most common is to have a file .Xauthority in your home directory which contains a token that is checked by the X server. If you install a script in your own crontab, it will run under your own user id (you probabl shouldn't use sudo), so it will read the right .Xauthority file. If you run from the root crontab, or from an init script, it will run as the root user, so it will have access to everything but will still need to know where to take the token from. I think that adding export XAUTHORITY=/home/joe/.Xauthority to the script will work. (Assuming your user id is joe.)
I've built a shell script that uses inotifywait to automatically detect file changes on a specific directory. When a new PDF file is dropped in the directory this script should go off and it should then trigger ocropus-parser to execute some commands on it. The code:
#!/bin/sh
inotifywait -m ~/Desktop/PdfFolder -e create -e moved_to |
while read path action file; do
#echo "The file '$file' appeared in directory '$path' via '$action'"
# Check if the file is a PDF or another file type.
if [ $(head -c 4 "$file") = "%PDF" ]; then
echo "PDF found - filename: " + $file
python ocropus-parser.py $file
else
echo "NOT A PDF!"
fi
done
This works pretty well when I run this script through the terminal with ./filenotifier.sh but when I reboot my Linux (Ubuntu 14.04) my shell will no longer run and it will not restart after a reboot.
I've decided to create an init script that starts at boot time (I think). I did this by copying the file filenotifier.sh to init.d:
sudo cp ~/Desktop/PdfFolder/filenotifier.sh /etc/init.d/
I've then gave the file the correct rights:
sudo chmod 775 /etc/init.d/filenotifier.sh
and finally I've added the file to update-rc.d:
sudo update-rc.d filenotifier.sh defaults
However when I reboot and drop a PDF in the folder ~/Desktop/PdfFolder nothing will happen and it seems that the script does not go off.
I'm really not experienced with init.d, update-rc.d and deamon so I'm not sure what is wrong and if this is even a good approach or not.
Thanks,
Yenthe
Being an init-script, you should add the LSB header to your script, like this:
#!/bin/sh
### BEGIN INIT INFO
# Provides: filenotifier
# Required-Start: $remote_fs $syslog
# Required-Stop: $remote_fs $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Something
# Description: Something else
### END INIT INFO
inotifywait -m ...
This way, you can ensure that your script runs when all mount points are available (thanks to Required-Start: $remote_fs). This is essential if your home directory is not on the root partition.
Another problem is that in your init-script you're using ~:
inotifywait -m ~/Desktop/PdfFolder ...
The ~ expands to the current user home directory. Init-scripts are run as root, so it'll expand to /root/Desktop/PdfFolder. Use ~<username> instead:
inotifywait -m ~yenthe/Desktop/PdfFolder ...
(Assuming that your username is yenthe.)
Or perhaps switch user before starting (using sudo).
$file is the basename without the path to the directory. Use "$path/$file" in your commands:
"$(head -c 4 "$path/$file")"
python ocropus-parser.py "$path/$file"
Maybe consider using name instead of file, to avoid confusion.
If things are not working, or if in general you want to investigate something, remember to use ps, like this:
ps -ef | grep inotifywait
ps will tell you, for example, whether your script is running and if inotifywait was launched with the correct arguments.
Last but not least: use "$file", not $file; use "$(head -c 4 "$file")", not $(head -c 4 "$file"); use read -r, not read. These tips can save you a lot of headaches in the future!
For that purpose the developers of inotify created incron. It is a cron like daemon which executes scripts based on changes in a watched file/directory rather than on time events.
I placed a link to my scripts in the rc.local to autostart it on linux debian boot. It starts and then stops at the while loop. It's a netcat script that listens permantently on port 4001.
echo "Start"
while read -r line
do
#some stuff to do
done < <(nc -l -p 4001)
When I start this script as root with command ./myscript it works 100% correctly. Need nc (netcat) root level access or something else?
EDIT:
rc.local
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
/etc/samba/SQLScripts
exit 0
rc.local starts my script "SQLScripts"
SQLScripts
#! /bin/sh
# The following part always gets executed.
echo "Starting SQL Scripts" >> /var/log/SQLScriptsStart
/etc/samba/PLCCheck >> /var/log/PLCCheck &
"SQLScripts" starts "PLCCheck" (for example only one)
PLCCheck
#!/bin/bash
echo "before SLEEP" >> /var/log/PLCCheck
sleep 5
echo "after SLEEP" >> /var/log/PLCCheck
echo "vor While" >> /var/log/PLCCheck
while read -r line
do
echo "in While" >> /var/log/PLCCheck
done < <(netcat -u -l -p 6001)
In an rc script you have root level access by default. What does "it stops at the while loop" mean? It quits after a while, or so? I guess you need to run your loop in the background in order to achieve functionality usual in autostart scripts:
echo "Starting"
( while read -r line
do
#some stuff to do
done << (nc -l -p 4001) ) &
echo "Started with pid $( jobs -p )"
I have tested yersterday approximatly the same things, and I have discover that you can bypass the system and execute your netcat script with the following crontask. :
(every minute, but you can ajust that as you want.)
* * * * * /home/kali/script-netcat.sh // working for me
#reboot /home/kali/script-netcat.sh // this is blocked by the system.
According to me, I think that by default debian (and maybe others linux distrib) block every script that try to execute a netcat command.
I wrote a bash script that changes the wallpaper (for GNOME3).
#!/bin/bash
# Wallpaper's directory.
dir="${HOME}/images/wallpapers/"
# Random wallpaper.
wallpaper=`find "${dir}" -type f | shuf -n1`
# Change wallpaper.
# http://bit.ly/HYEU9H
gsettings set org.gnome.desktop.background picture-options "spanned"
gsettings set org.gnome.desktop.background picture-uri "file://${wallpaper}"
Script executed in a terminal emulator (eg gnome-terminal) works great. During the execution by cron, or ttyX terminal getting the error:
** (process:26717): WARNING **: Command line `dbus-launch --autolaunch=d64a757758b286540cc0858400000603 --binary-syntax --close-stderr' exited with non-zero exit status 1: Autolaunch error: X11 initialization failed.\n
** (process:26717): WARNING **: Command line `dbus-launch --autolaunch=d64a757758b286540cc0858400000603 --binary-syntax --close-stderr' exited with non-zero exit status 1: Autolaunch error: X11 initialization failed.\n
** (process:26721): WARNING **: Command line `dbus-launch --autolaunch=d64a757758b286540cc0858400000603 --binary-syntax --close-stderr' exited with non-zero exit status 1: Autolaunch error: X11 initialization failed.\n
** (process:26721): WARNING **: Command line `dbus-launch --autolaunch=d64a757758b286540cc0858400000603 --binary-syntax --close-stderr' exited with non-zero exit status 1: Autolaunch error: X11 initialization failed.\n
Finally I managed how to solve this issue after many, many attempts.
Indeed, the problem occur because cron uses only a very restricted set of environment variables. And the only one environment variable that is responsible for running in the right way the script from the question when this is set as a cron job is DBUS_SESSION_BUS_ADDRESS, not DISPLAY or XAUTHORITY or GSETTINGS_BACKEND or something else. This fact was also pointed well in this answer.
But the problem in this answer is that there's no guarantee that the DBUS_SESSION_BUS_ADDRESS variable from that file from ~/.dbus/session-bus/ directory is updated to the current value from the current gnome session. To go over this problem a method would be to find the PID of a process in the current gnome session, and obtain the dbus address from its environment. We can do this as follow:
PID=$(pgrep gnome-session) # instead of 'gnome-session' it can be also used 'noutilus' or 'compiz' or the name of a process of a graphical program about that you are sure that is running after you log in the X session
export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-)
That being said, the script should look like:
#!/bin/bash
# TODO: At night only dark wallpapers.
# Wallpaper's directory.
dir="${HOME}/images/wallpapers/"
# export DBUS_SESSION_BUS_ADDRESS environment variable
PID=$(pgrep gnome-session)
export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-)
# Random wallpaper.
wallpaper=`find "${dir}" -type f | shuf -n1`
# Change wallpaper.
# http://bit.ly/HYEU9H
gsettings set org.gnome.desktop.background picture-options "spanned"
gsettings set org.gnome.desktop.background picture-uri "file://${wallpaper}"
I found some solutions. When you export a variable DBUS_SESSION_BUS_ADDRESS contained in the file ~/.dbus/session-bus/*, dbus-launch does not tell more about the error. However, instead of wallpaper there are artefacts.
Added code:
sessionfile=`find "${HOME}/.dbus/session-bus/" -type f`
export `grep "DBUS_SESSION_BUS_ADDRESS" "${sessionfile}" | sed '/^#/d'`
Now the script looks like this:
#!/bin/bash
# TODO: At night only dark wallpapers.
# Wallpaper's directory.
dir="${HOME}/images/wallpapers/"
# Weird, but necessary thing to run with cron.
sessionfile=`find "${HOME}/.dbus/session-bus/" -type f`
export `grep "DBUS_SESSION_BUS_ADDRESS" "${sessionfile}" | sed '/^#/d'`
# Random wallpaper.
wallpaper=`find "${dir}" -type f | shuf -n1`
# Change wallpaper.
# https://superuser.com/questions/298050/periodically-changing-wallpaper-under-gnome-3/298182#298182
gsettings set org.gnome.desktop.background picture-options "spanned"
gsettings set org.gnome.desktop.background picture-uri "file://${wallpaper}"
Tried this and it worked great for me:
dbus-launch --exit-with-session gsettings set schema key value
Or from root cron:
sudo -u user dbus-launch --exit-with-session gsettings set schema key value
Credit: http://php.mandelson.org/wp2/?p=565
add export DISPLAY=:0 && export XAUTHORITY=/home/username/.Xauthority , where username is your ubuntu username. It should fix the X11 authorisation error.
To change your wallpaper through cron, just do this directly in your crontab :
Execute crontab -e
Add lines like this :
30 09 * * * DISPLAY=:0 GSETTINGS_BACKEND=dconf /usr/bin/gsettings set org.gnome.desktop.background picture-uri file:////home/elison/Pictures/morning.jpg
00 12 * * * DISPLAY=:0 GSETTINGS_BACKEND=dconf /usr/bin/gsettings set org.gnome.desktop.background picture-uri file:////home/elison/Pictures/noon.jpg
Also see this solution that work for me:
https://unix.stackexchange.com/questions/111188/using-notify-send-with-cron#answer-111190
:
You need to set the DBUS_SESSION_BUS_ADDRESS variable. By default cron does not have access to the variable. To remedy this put the following script somewhere and call it when the user logs in, for example using awesome and the run_once function mentioned on the wiki. Any method will do, since it does not harm if the function is called more often than required.
#!/bin/sh
touch $HOME/.dbus/Xdbus
chmod 600 $HOME/.dbus/Xdbus
env | grep DBUS_SESSION_BUS_ADDRESS > $HOME/.dbus/Xdbus
echo 'export DBUS_SESSION_BUS_ADDRESS' >> $HOME/.dbus/Xdbus
exit 0
This creates a file containing the required Dbus evironment variable. Then in the script called by cron you import the variable by sourcing the script:
if [ -r "$HOME/.dbus/Xdbus" ]; then
. "$HOME/.dbus/Xdbus"
fi
And finally the ugly, no cron at all (darn it)! Using other methods the changes get set in gconf, but the image does not change. Maybe it is because I am running Deepin's DDE (dde makes use of the same path, different key). Ugly for the rescue: A final attempt to make this saga work.
With this script the wallpaper is changed every 420 seconds (7 minutes) in an endless loop picking a random wallpaper from one of 4 sets (or directories), acordingly to the time of the day or night.
I've created a .desktop file and added this .desktop file to the "~/.config/autostart". I've also created another pair script/desktop without the loop to be on my dock, so I can click on it and change it on fly too.
Set the ugly up: save the script as wallpaperd somewhere and make it executable:
chmod +x wallpaperd
Now create a folder called Wallpaper inside the Pictures directory. Inside this Wallpaper folder create 4 more folders with the names afternoon, duskdawn, morning and night. Put the image files you wish in those 4 directories.
mkdir -p ~/Pictures/Wallpaper/morning
mkdir ~/Pictures/Wallpaper/afternoon
mkdir ~/Pictures/Wallpaper/night
mkdir ~/Pictures/Wallpaper/duskdawn
wallpaperd
#!/bin/bash
for (( ; ; ))
do
me="MyUser" # Change me!
morning="morning"
afternoon="afternoon"
dawn="duskdawn"
night="night"
dusk="duskdawn"
now="morning"
hour=$(date +%R | sed 's/\:.*//')
if [ "$hour" -ge 7 ] && [ "$hour" -lt 12 ]
then
now="morning"
elif [ "$hour" -ge 12 ] && [ "$hour" -lt 17 ]
then
now="afternoon"
elif [ "$hour" -ge 17 ] && [ "$hour" -lt 18 ]
then
now="duskdawn"
elif [ "$hour" -ge 18 ] && [ "$hour" -le 23 ]
then
now="night"
elif [ "$hour" -ge 0 ] && [ "$hour" -lt 6 ]
then
now="night"
elif [ "$hour" -ge 6 ] && [ "$hour" -lt 7 ]
then
now="duskdawn"
fi
imgPath="/home/$me/Pictures/Wallpaper/$now/"
imgFile=$(ls -1 $imgPath | shuf -n 1 | awk '{print $NF}')
export bgNow=""$imgPath$imgFile""
# Deepin desktop
/usr/bin/gsettings set com.deepin.wrap.gnome.desktop.background picture-uri "$bgNow"
# Gnome desktop
#/usr/bin/gsettings set org.gnome.desktop.background picture-uri "$bgNow"
sleep 420
done
Set the proper gsettings command for your desktop in script!
wallyd.desktop
** Autostart Path: /home/YOUR_USER/.config/autostart/wallyd.desktop**
[Desktop Entry]
Categories=System;
Comment=Change Wallpapers Agent
Exec=/home/$USER/Bin/wallpaperd
Icon=computer
Name=Wally Daemon
NoDisplay=false
Terminal=false
Type=Application
Edit the script's path to match the path where you saved the script.
No loop
To create a desktop icon without the loop, only to change the wally and quit do this:
Save the script as wallpaper (without the d at the end) and remove these lines:
for (( ; ; ))
do
done
Use the template above to create another .desktop file for this non looped wallpaper script. Change the Name and the Exec path for the non looped script.
Save this .desktop here:
/usr/share/applications/wally.desktop
Drag it to your taskbar or dock. Click it and it will change the wallpaper on the fly.
When setting the DBUS_SESSION_BUS_ADDRESS environment variable, the PID=$(pgrep gnome-session) command may return multiple values in certain cases. This can cause issues when setting the environment variable using the grep command.
To address this issue, you can use the pgrep command with the -t option to limit the search to a specific terminal. In this case, you can use PID=$(pgrep -t tty2 gnome-session) to limit the search to the second terminal (tty2) and ensure that only one PID is returned.
Therefore, for Ubuntu 22.04, you can modify the command to:
PID=$(pgrep -t tty2 gnome-session)
export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-)
This should allow you to set the DBUS_SESSION_BUS_ADDRESS environment variable correctly, even when multiple gnome-session processes are running.
Thanks to Ray Foss for providing this solution in the comments to the original answer.