Raspberry Pi pico script exeucte kill - raspberry-pi-pico

I wrote a script with the while loop command and I executed it on my Raspberry Pi, however I didn't put a break in it, so it won't stop. I tried to interrupt it, but the script is still being executed. I used thonny Python and I tried to exit it, Ctrl+C, soft reboot. I even tried to put it in storage mode and reset it, but it's still being executed. I'm trying to work out how to completely delete the script from the pico itself. Do you have any ideas?
Python:
from machine import Pin
from time import sleep
led = Pin(25, Pin.OUT)
while True:
led.toggle()
sleep(0.5)

I'm reasonably sure that RPiOS has a task manager, so you could try killing it in that.
If it doesn't then open up your terminal and run ps -ef to find the PID of the python process (it should show the name of the command). Then run sudo kill -9 <PID> to kill it manually.
Edit:
I now understand that the RPi Pico is actually a microcontroller. Have you tried uploading a new program or just unplugging it from power to force it to reboot?

Related

suspend/resume a process started from ~/.bashrc

I want to start a long-running python process when I log-in to a server.
So I put something like this into ~/.bashrc
python long_running_process.py
This correctly starts the python process on login. The problem here is that I'm not able to suspend it later (with ctrl-z). I can only exit the process by presssing ctrl-c.
I'd like to be able to pause/suspend and resume the python process if possible. This is different from "backgrounding" the process which has been asked and answered here
EDIT: I found a hack that kindof works. I create a dummy shell-script called ~/run.sh and make it executable. Then I put
#!/bin/bash
set -m
python long_running_process.py
in ~/run.sh.
Lastly, I call ~/run.sh in ~/.bashrc instead of starting the python process directly. Giving set -m enables job-control in the script (which is disabled by default for shell-scripts it seems)
This is very hacky. If someone has a nicer/cleaner solution, I'd be very interested in hearing it
You can use POSIX signals, sent with the kill command. I'll run this little Python script that prints its process id and the time once per second, then pause it then resume it:
#!/usr/bin/env python3
import os
import time
while True:
print(f"Process id: {os.getpid()}, time: {int(time.time())}")
time.sleep(1)
It started with process id 63070, so I can pause it with:
kill -STOP 63070
and then resume it with:
kill -CONT 63070
You can stop the process with command kill -SIGSTOP pid where pid is the process id (you can find it with command ps -ef | grep process_name ) and then continue the process with signal SIGCONT.

How to Turn Off a Program Running from .bash_profile

I am working with a Raspberry Pi running linux, and have modified the .bash_profile file in order to a run a program I've made automatically upon login. This works great, but I was wondering how to turn the program off, since for ctrl+c I would need to be running the program in the terminal.
You can use Kill to terminate program by its process Id, Top command will list all the processes, You can also use Pkill, which will Terminate the process by its name.
-9 option forces process to shut down, so its very commonly used.
Example:
kill -9 "Process ID without Quotation marks"
pkill -9 "Name with Quotation marks (Case Sensitive)"
Check this.
I always use
pkill - f processname

How to tell Bash to not stop the simulations when ssh disconnects?

I am running some simulations on another machine via ssh. Here is what I do
ssh username#ipp.ip.ip.ip
Go to the right directory
cd path/to/folder
And then I just call my executable
.\myexecutable.exe
The issue is that every time the ssh disconnect, the simulations stops. How can I make sure the simulations doesn't stop on the other machine? Will I somehow receive potential error messages (assuming the code will crash) once I reconnect (ssh)?
You should launch a screen or tmux to create a terminal from which you can detach, leave running in the background and later reattach.
Further reading:
http://ss64.com/osx/screen.html
https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man1/screen.1.html
You may also want to try out Byobu:
http://byobu.co
run your command as follows : nohup ./myexecutable.exe >nohup.out 2>&1 &
The & is to run the command in the background
The >nohup.out 2>&1 sends your stdout and stderr to nohup.out)
Note the '/' as opposed to '\' - which won't work on osx

Automate a Ruby command without it exiting

This hopefully should be an easy question to answer. I am attempting to have mumble-ruby run automatically I have everything up and running except after running this simple script it runs but ends. In short:
Running this from terminal I get "Press enter to terminate script" and it works.
Running this via a cronjob runs the script but ends it and runs cli.disconnect (I assume).
I want the below script to run automatically via a cronjob at a specified time and not end until the server shuts down.
#!/usr/bin/env ruby
require 'mumble-ruby'
cli = Mumble::Client.new('IP Address', Port, 'MusicBot', 'Password')
cli.connect
sleep(1)
cli.join_channel(5)
stream = cli.stream_raw_audio('/tmp/mumble.fifo')
stream.volume = 2.7
print 'Press enter to terminate script';
gets
cli.disconnect
Assuming you are on a Unix/Linux system, you can run it in a screen session. (This is a Unix command, not a scripting function.)
If you don't know what screen is, it's basically a "detachable" terminal session. You can open a screen session, run this script, and then detach from that screen session. That detached session will stay alive even after you log off, leaving your script running. (You can re-attach to that screen session later if you want to shut it down manually.)
screen is pretty neat, and every developer on Unix/Linux should be aware of it.
How to do this without reading any docs:
open a terminal session on the server that will run the script
run screen - you will now be in a new shell prompt in a new screen session
run your script
type ctrl-a then d (without ctrl; the "d" is for "detach") to detach from the screen (but still leave it running)
Now you're back in your first shell. Your script is still alive in your screen session. You can disconnect and the screen session will keep on trucking.
Do you want to get back into that screen and shut the app down manually? Easy! Run screen -r (for "reattach"). To kill the screen session, just reattach and exit the shell.
You can have multiple screen sessions running concurrently, too. (If there is more than one screen running, you'll need to provide an argument to screen -r.)
Check out some screen docs!
Here's a screen howto. Search "gnu screen howto" for many more.
Lots of ways to skin this cat... :)
My thought was to take your script (call it foo) and remove the last 3 lines. In your /etc/rc.d/rc.local file (NOTE: this applies to Ubuntu and Fedora, not sure what you're running - but it has something similar) you'd add nohup /path_to_foo/foo 2>&1 > /dev/null& to the end of the file so that it runs in the background. You can also run that command right at a terminal if you just want to run it and have it running. You have to make sure that foo is made executable with chmod +x /path_to_foo/foo.
Use an infinite loop. Try:
while running do
sleep(3600)
end
You can use exit to terminate when you need to. This will run the loop once an hour so it doesnt eat up processing time. An infinite loop before your disconnect method will prevent it from being called until the server shuts down.

Can a standalone ruby script (windows and mac) reload and restart itself?

I have a master-workers architecture where the number of workers is growing on a weekly basis. I can no longer be expected to ssh or remote console into each machine to kill the worker, do a source control sync, and restart. I would like to be able to have the master place a message out on the network that tells each machine to sync and restart.
That's where I hit a roadblock. If I were using any sane platform, I could just do:
exec('ruby', __FILE__)
...and be done. However, I did the following test:
p Process.pid
sleep 1
exec('ruby', __FILE__)
...and on Windows, I get one ruby instance for each call to exec. None of them die until I hit ^C on the window in question. On every platform I tried this on, it is executing the new version of the file each time, which I have verified this by making simple edits to the test script while the test marched along.
The reason I'm printing the pid is to double-check the behavior I'm seeing. On windows, I am getting a different pid with each execution - which I would expect, considering that I am seeing a new process in the task manager for each run. The mac is behaving correctly: the pid is the same for every system call and I have verified with dtrace that each run is trigging a call to the execve syscall.
So, in short, is there a way to get a windows ruby script to restart its execution so it will be running any code - including itself - that has changed during its execution? Please note that this is not a rails application, though it does use activerecord.
After trying a number of solutions (including the one submitted by Byron Whitlock, which ultimately put me onto the path to a satisfactory end) I settled upon:
IO.popen("start cmd /C ruby.exe #{$0} #{ARGV.join(' ')}")
sleep 5
I found that if I didn't sleep at all after the popen, and just exited, the spawn would frequently (>50% of the time) fail. This is not cross-platform obviously, so in order to have the same behavior on the mac:
IO.popen("xterm -e \"ruby blah blah blah\"&")
The classic way to restart a program is to write another one that does it for you. so you spawn a process to restart.exe <args>, then die or exit; restart.exe waits until the calling script is no longer running, then starts the script again.

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