I am currently working on a home project with a Raspberry Pi and the 7" display. Almost everything works, only the last bit I am a bit confused with. A chromium window in kiosk mode is open which refreshes on mouse movement. Also on mouse movement I want to change the backlight for a few seconds to full light.
The script below works so far stand-alone:
#!/bin/bash
while true; do
pos1=$(xdotool getmouselocation)
sleep 0.5
pos2=$(xdotool getmouselocation)
if [[ $pos1 != $pos2 ]]; then
sudo /usr/local/bin/rpi-backlight -b 100
sleep 10
sudo /usr/local/bin/rpi-backlight -b 0 -d 2
fi
done
I already tried to make it happen by
putting it in one script together with the chromium call,
opening both in autostart,
creating a systemd service for the script above. It does not seem to work in the background.
Can anyone tell me, where I am mistaken?
I made it happen by putting both in autostart. My syntax seemed to be wrong.
#/path/script.sh &
#chromium-browser --kiosk http://website.xyz
works like a charme, where ampersand "&" is for making it a background process.
Related
To learn about BASH scripting, I set myself the objective to write a Cron script which shuts down a PC with Mint 20 when activity on the Ethernet interface dropped below a threshold over an 1 hour.
I mainly (but not exclusively) use the PC as File/DLNA Server. The script works, but now I find that it also shuts down the PC the rare times I'm using the the front end. So I want my script to verify if the screen has been blanked (As per Power Management settings)
To test the principle I included this in my script:
screenon=$(/usr/bin/xset -q | grep 'Monitor is' | cut -d "s" -f 2)}
which when run in a terminal window gives (debug: set -x)
screenon= On
but when run from cron gives. (logger)
/usr/bin/xset: unable to open display ""
I have learned about similar problems, but cannot figure out how to solve this.
My script includes:PATH=$PATH:/usr/local/bin
and my PATH is: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
Thanks in advance for any help.
On Mac OS is it possible to create an Automator/Bash/Java/ApplieScript that runs an bash-command to do something (for example chance the screen resolution) after that runs an application (for example a game that needs a specific screen resolution) then waits until the application has been terminated and after that does one final thing (for example change the screen resolution again)?
I tried to work with all Automator, Bash, Java and ApplieScript. I even tried to combine multiple of them to one chain of things that runs other things just to run something else until it terminates and then run something else, but non of that semms to work properly.
I got the terminal commands that changes screen resolution and I also got the terminal command that runs the Game, but I can't bring it together in an logical correct chain of things to happen...
The Commands are:
do shell script "/Volumes/Sierra/Users/xyz/Documents/cscreen -x 1600 -y 900 -r 60"
do shell script "open steam://run/8930"
do shell script "/Volumes/Sierra/Users/xyz/Documents/cscreen -x 1280 -y 720 -r 60"
What you want is the -W argument for open:
-W Causes open to wait until the applications it opens (or that were already open) have exited. Use with the -n
flag to allow open to function as an appropriate app for the $EDITOR environment variable.
So in your example I would make a script like this:
#!/bin/bash
/Volumes/Sierra/Users/xyz/Documents/cscreen -x 1600 -y 900 -r 60
open -W steam://run/8930
/Volumes/Sierra/Users/xyz/Documents/cscreen -x 1280 -y 720 -r 60
Now open should not return control to the shell until steam exits.
I just wrote my first bash script to start some redis instances on a development server. While it is mostly working, the last opened redis instance is blocking the active terminal – though I have the trailing & sign and the other started instances aren't blocking the terminal. How would I push them all to the background?
Here's the script:
#!/bin/bash
REDIS=(6379 6380 6381 6382 6383 6390 6391 6392 6393)
for i in "${REDIS[#]}"
do
:
redis-server --port $i &
done
It sounds like your terminal is not actually blocked, your prompt just got overwritten. It's a purely cosmetic issue. Due to the way terminals work, bash doesn't know to redraw it so it looks like the command is in the foreground.
Run the script again, and blindly type lsEnter. You'll probably see that the shell responds as normal, even though you can't see the prompt.
You can alternatively just hit Enter to get bash to redraw the prompt.
$ matlab -nodesktop -nojvm &
How would I execute matlab commands on the session that was just created?
In other words, I want to have a matlab session running in the background, and execute matlab commands and/or scripts from an arbitrary terminal at any given time without having to create a new session.
I would suggest a similar solution as carandraug did, only I prefer tmux as the multiplexer. It may be a bit tricky getting the commands passed in correctly so create a shell-script that handles the details.
Let's say you've started matlab in a terminal like this:
tmux new -s matlab "matlab -nodesktop -nojvm"
Now a tmux session called matlab is running matlab with no gui.
Create this shell-script:
mx
#!/bin/bash
if [[ $# -eq 0 ]]; then
while read; do
tmux send-keys -t matlab "$REPLY"$'\n'
done
else
tmux send-keys -t matlab "$#"$'\n'
fi
In a different terminal you can now run quoted matlab commands:
mx "A = reshape(1:9, 3, 3)"
Or even pass commands in through a pipe:
for mat in A B C; do echo "$mat = reshape(1:9, 3, 3)"; done | mx
A possibility is to start a screen session, then start matlab on it, and detach from it. Anytime you want to use it, just fire up a terminal and reattach that screen session.
Basically start screen (just type screen at a terminal), and start your matlab session. Then detach from the session (Ctrl+A followed by pressing D) and you'll be back to your terminal. You can close the window no problem, any process that started on screen will keep on running. Whenever you want to get it again (it's called reattach the session), just use screen -r. Take a look at the man page for all the other options.
Note that a screen session can have any number of windows and you can also have multiple screen session at the same time. Take a good luck at some tutorials online, it's an extremely useful tool, specially but not only, if you connect a lot to other systems that may have need to run long jobs.
The main problem I'm having is to background a screen session from Hudson-CI. The shell steps are that I need to start a screen session from a script that is launched by another script. Heres' a simple test:
test.sh:
#!/bin/bash
myscreen.sh
myscreen.sh:
#!/bin/bash
screen -dm -S myscreen pingit.sh
pingit.sh:
#!/bin/bash
ping google.com
If I run ./myscreen.sh I get a screen launched that runs the ping continuously without a problem.
If I run ./test.sh, the screen is never started. I'm assuming there's something basic that I'm either forgetting or not understanding, but I can't figure out what. I thought this would work.
The real reason I want to do this is to have Hudson CI launch a continuous-test script which starts as a screen session so that it can continue in the background. What I'm finding is that the screen session terminates once the task is completed in Hudson.
Any ideas on why I can't launch a persistent screen session from a grand-parent script? Or any ideas on how to deal with this?
This is on OSX 10.6, with screen built from source (so it should work the same as linux I think).
If I run your test.sh, I get the error message
./test.sh: Zeile 2: myscreen.sh: Kommando nicht gefunden.
i.e. command not found. You'll have to write ./myscreen.sh, if the current directory is not on the path. (Is it for you? It should not.) The same is valid for the screen call.
Changing both files to
#!/bin/bash
./myscreen.sh
and
#!/bin/bash
screen -dm -S myscreen ./pingit.sh
I can start my screen without any problems.
I'm on Linux (OpenSUSE) with
$ screen --version
Screen version 4.00.03 (FAU) 23-Oct-06
here.
I don't know why I did not find the following references before, but these were the links that helped me solve the problem:
https://serverfault.com/questions/155851/run-gnu-screen-from-script
http://wiki.hudson-ci.org/display/HUDSON/Spawning+processes+from+build
There are 2 issues here - one of screen being persisted after being launched by a grand-parent process. The other that hudson terminates a session after it completes its task.
The screen problem is resolved by zombie'ing the process as follows:
screen -d -m -S myscreen && screen -S myscreen -X zombie qr && screen -S myscreen -X screen pingit.sh
The Hudson-CI problem turns out to be a bug that's easily resolved per the above link. The solution is to add BUILD_ID=something into the shell script. So if the test.sh script from above is actually the Hudson Build shell execute, then it would have to be changed to:
#!/bin/bash
BUILD_ID=dontkillthisprocess
myscreen.sh
Once both of these steps are implemented, things work fine.