I was trying to figure out how to run a program at boot, but after realizing this program is an infinite loop, I have no way of getting out, or back to the terminal. Right when I give the Pi power it just goes right to the program on a black background. I don't remember exactly what I did to make it run at boot, I believe I just added some code in a place right above something that said "exit 0" and below something that says "esac". I don't remember the command that even got me there. (I am new to the Pi and Python and have just been playing around..unsucessfully.)
If anyone could help me either delete this program or get me to be able to edit it so I can fix the infinite loop that would be great. I'd rather not have to completely over-write the sd card with a fresh raspbian. But like I said I can't do anything at boot, and Ctrl + C doesn't do anything nor Ctrl + Alt + Delete.
EDIT: When I put the SD card in my computer, I see a list of 11 files:
bootcode
cmdline
config
fixup
fixup_cd
issue
kernel
kernel_cutdown
kernel_emergency
start.elf
start_cd.elf
None of these mean anything to me...
Update: Looks like I failed to get that you want to interrupt the running bootprocess and stop the script.
The simplest idea would be to turn of the pi, unplug the sd card and plug it into your desktop, (re)move the script and boot again.
Processes spawned during boot are stored in scripts in /etc/init.d/.... These scripts are called by the init process, the first process on a Linux machine (PID:1)
But init starts not all scripts in /etc/init.d. This depends on the run level. On a debian system there are 7 run levels.
For every run level there is a folder called like:
/etc/rc0.d
...
/rc6.d
in which are softlinks to scripts from /etc/init.d are stored.
To remove a script from being executed on every boot you'll delete all links from that folders. Usually on debian systems this is done using the update-rc.d tool:
update-rc.d NAME_OF_INIT_SCRIPT remove
You should also have a look at the file /etc/rc.local
Alt + PrintScn + k to kill the process stuck running from rc.local
You can use the cmdline.txt.
First, add or modify the cmdline.txt file on your sd card. Add "init=/bin/sh", then restart your Pi, and you can see a command line prompt.
Type 'sudo nano /etc/rc.local' to edit the file, and comment or delete the line containing the error. After that restart.
I had exactly the same issue, couldn't quit the process using CTRL+C. I edited the cmdline.txt like stated above, but then the pi didn't load the necessary usb drivers for my keyboard.
So eventually I logged in over SSH to the pi, and modified my rc.local file that way.
In my case worked combination "Alt" + "F4", it stops the current session and opens the login screen
I had the same problem as explained at the beginning of this Post. My Python app was caught in an endless loop.
I tried the Ctrl+Alt+F2 Command as recommended in many posts found in Internet without any terminal window being open. Apparently, after many other trials and reboots I saw a glimpse of a Terminal window each time the loop of my application restarted. It was impossible to catch anything until I started recording the screen using the slow motion video of my mobile phone and, yes, a terminal window with the Linux prompt was active, and able to accept keyboard entries.
All I did was (almost blindly) editing the culprit file with the
sudo nano filename command
and entering some characters in order to actually corrupt such file, saving and closing it, a rebooting the Pi.
At the end of the boot, the file produced an error but the system kept ready to operate.
I was then able to fix the bug in a normal way.
It hope this may be useful to others. In my case it spared me of burning a new Raspbian and losing all my previous work.
I got myself stuck in exactly the same problem. Luckily I had the ssh enabled, apparently this is disabled by default on Raspbian Jessie, so this may not work for all.
The exit 0 is the line in /etc/rc.local where you would have added in the script that is now running in a continuous mode. If you can ssh into the Pi using Putty and the Pi's IP address then
sudo nano /etc/rc.local
Scroll down to the bottom of the file and remove the offending program, then sudo reboot
They way to prevent this issue from happening is to add an & (ampersand) to the end of the line to fork the process and run it as a separate process like so
python /home/pi/myscript.py &
as specified in https://www.raspberrypi.org/documentation/linux/usage/rc-local.md
The ampersand allows the command to run in a separate process and continue booting with the process running.
Related
I have a python3 program that I run without any problems on a headless raspberry pi configuration where I connect using ssh. I logon to my pi, start a tmux session, and run the program. It will run indefinitely. During development when an exception would occur I the python program would terminate and I would see the error info.
Now if my pi were to reboot while I wasn't around I would want it to run this program automatically. I implemented the following steps to make this happen:
I created a script which contains this line:
tmux new-session -d -s xbnw 'python3 /home/pi/python/XbNWSer05.py'
Then I modified /etc/rc.local to include this line:
sudo -u pi bash /home/pi/tmux_xbnw.sh
Now when I reboot my pi everything works for a few minutes. The program is clearly running. I can logon and attach to the session and see my debug output and everything looks fine.
After a few minutes though something goes wrong and if I'm logged on and connected to the tmux session I suddenly find myself at a command prompt as though the program never ran. Also the tmux session is no longer active. There's no indication what happened.
1) Am I starting my program improperly?
2) If so is there a way to figure out what happened?
Add a logfile, either hacky by hand or with the logger module. Then you can find out if the programm started and you can log every minute or so to see when it dies and what was the last state.
You can also check the syslog whether there was a reboot. I had a bad power supply cable which made my Pi reboot in past...
I wanted to have my Raspberry Pi update the system clock from a GPS on start up but now something has gone wrong and I can't login.
I created a bash script that calls 'sudo -i' and a few other gpsd related instructions. I pointed the /etc/profile towards the script. If I Ctrl+C to get to a prompt I get root access but the directories are listing nothing when I use the 'ls' command. If I exit from root I get stuck again. I figure that if I could delete the bash script the problem would go away but I don't know how to view that partition of the SD card on a PC. Any suggestions?
Ok, I solved the problem. There is a ext4 partition editor called ExtFS for Windows. You can view and edit an ext4 partition easily in this program. You can download it here.
I try to auto start a python script at startup, then reboot my Raspberry Pi to see if it works.
sudo nano /etc/xdg/lxsession/LXDE/autostart
Instead of a normal desktop display, I get a blank screen open box that can only open the menu by right click. So I tried to delete the code I have implemented on start up then reboot again, but the same thing happens. I uninstall open box hoping that it would solve the problem, but I still get the blank screen and the mouse cursor becomes an "X" icon. Has anybody encountered this problem before?
I had a similar problem with my Pi and, after checking the link provided by Matt (lxde wiki), I found what the problem was and the solution.
I had 2 autostart files:
Global commands:
/etc/xdg/lxsession//autostart
Local commands:
~/.config/lxsession/LXDE-pi/autostart
And, according to documentation "If both files are present, only the entries in the local file will be executed."
And my local file was empty.
After deleting the empty file, LXDE desktop was back and no more black screen.
The blank screen open box is the default openbox theme (for lack of a better word). Openbox is required for lxde so you should reinstall that first. To autostart something in LXDE you can create desktop files in your ~/.config/autostart directory (according to the lxde wiki) to avoid messing with the autostart file
Try reinstalling openbox and returning the /etc/xdg/lxsession/LXDE/autostart to the way you found it and see what happens. You might have accidentally messed up another autostart command
I went into ~/.config/autostart and found a file named lxde.desktop which I edited and commented out (using #) a line that began with something like OnlyShowIn or something similar. (After a reboot that line disappeared so I don't remember exactly what It was, It "could" have been NotShowIn but I thought it was something different)
After a reboot my desktop came back *fine!
*I had a bunch of GDBus.Error:org.freedesktop.PolicyKit1 errors which I cleared up by typing lxsession-edit in a terminal window and then unchecking LXDE and rebooting
If you figure out my "OnlyShowIn" confusion - please comment to clear it up for myself and others
I experienced same behavior, and found the following mistake I made:
I ran:
sudo dd bs=1m if=raspbian.img of=/dev/disk2 conv=sync
but I accidentally omitted the r before disk2
I Reran:
sudo dd bs=1m if=raspbian.img of=/dev/rdisk2 conv=sync
and it booted up properly.
The successful boot on Pi showed a blue square immediately saying "reformatting disk".
My solution was to format the SD card with the ZIP file directly instead of the IMG file found inside after extraction. I got the zip file from the Raspbian download page found here:
https://www.raspberrypi.org/downloads/raspbian/
With an SD card formatted from the ZIP rather than its contained IMG, my operating system is loading as expected.
This solution was applied in Mac OSX using Apple Pi Baker software and the above linked image.
Here is the situation, I'm planning to use a simple script to start a program call "STAF", when the Suse system is fully booted. I have achieved this by putting it in the "/etc/init.d/", but this script is basically executed at the background, which means that I cannot see its progress.
When the "STAF" is started this way it works but it doesn't show any working progress when its running service (for example ping, or system backup), instead if I start the "STAF" manually by running the same script whit a terminal, the working progress of "STAF" can be seen on the terminal. Its sort of like the program needs to be started with a interactive terminal, but how can I make this starting process automatic and it should imitate human opening a terminal and run the script?
Sorry if I explained it poorly because its a confusing situation. Thanks.
First, go to the KDE Startup and Shutdown options under System Settings. Then add this command as a new startup script:
konsole -e bash nameofyourscript.sh
I believe the screen utility can do what you describe. Instead of running STAF on startup, you would run screen STAF. To open that terminal, you would run screen -ls to get the screen ID, and screen -r ... to open it.
(Disclaimer: I have not tried this.)
I have a process (Spark chat client) which needs to be run when my Ubuntu boots up. For this I have done followings.
I created a run.sh file which will fire up my application (and I check it's working)
I created a symbolic link from both /etc/rc5.d/ and /etc/rc3.d/ to my run.sh file. (A symbolic link is also working fine)
But my processes don't start up when my machine boots. (Is this the way to do it or am I doing the wrong thing here?)
I'm running on Ubuntu 10.04 LTS (Lucid Lynx).
Your solution would've worked in most Linux distributions. However, Ubuntu never goes past runlevel 2.
Just in case, this means the contents of rc?.d with ? > 2 are not used unless you manually raise the runlevel as root. Use rc2.d :)
The symlinks you created in /etc/rc5.d/ and /etc/rc3.d/ should be named S##name. S is for start, and the number ## gives an order in which the scripts are run.
Note also that the symlinks in these directories usually points to the actual script located in /etc/init.d/.
It looks like you want to run an X program when a user logs in, not a service on startup. Remember, in Linux there is no GUI; X is a program that runs to display graphics on the screen.
You likely want to set up a program to start on KDE/Gnome login. Each has their own way to do it, but is generally boils down to pointing at a script and saying "Run this."
Put the command to run that script in the /etc/rc.local file. I think it will run each time you log in to the system.