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Forum Index : Microcontroller and PC projects : Linux & pi
| Author | Message | ||||
lew247 Guru  Joined: 23/12/2015 Location: United KingdomPosts: 1702 |
Does anyone know how to get a script running at bootup using crontab? I have a program that works perfectly and it's called by ./programname.sh but I cannot get it to run on boot I've tried @reboot /usr/bin/sh /home/pi/programname.sh & @reboot /home/pi/programname.sh & @reboot /home/pi/./programname.sh & @reboot /home/pi/ ./programname.sh & none starts the program on boot I even tried @reboot python /home/pi/./programname.sh & Anyone know how to get this running on power up? my crontab works because I have a script to reconnect the wifi if it loses connection and that works beautifully |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 4147 |
For those who don't know, crontab is about things being run at specified times (cron being from the greek god Chronos). The times being somewhat akin to calendar entries. Which user's crontab have you tried? I'm guessing a non-root one called pi. If you've put the command(s) into a file called (say) mycrontab did you then issue the command crontab mycrontab ? You can check any time afterwards what cron knows using crontab -l I don't recall ever needing a trailing "&" so maybe that is the problem. I also expect cron wants a normal Linux text file with normal line endings (i.e. newline not such as CR LF). John |
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| lew247 Guru Joined: 23/12/2015 Location: United KingdomPosts: 1702 |
I really don't understand that question I used sudo crontab -e then used nano as the editor i followed the instructions here and checked many other pages on running programs on boot on the Pi |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3477 |
I put commands to be executed at power-up in /etc/rc.local sudo nano /etc/rc.local Give full path names to any commands you execute. PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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| lew247 Guru Joined: 23/12/2015 Location: United KingdomPosts: 1702 |
I've never got anything working in .etc/rc.local aparently it doesn't work so well in the latest Buster and onwards thats why I was trying Crontab My checkwifi program worked until I rebooted then didn't so I'm doing something wrong |
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hitsware2 Guru Joined: 03/08/2019 Location: United StatesPosts: 735 |
>> it doesn't work so well in the latest Buster IMO Buster should be called Busted ..... Stick with Stretch as much as possible ... my site |
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| lew247 Guru Joined: 23/12/2015 Location: United KingdomPosts: 1702 |
I don't want to use Stretch I have a reason for using the latest Pi OS for those that actually know about Crontab any help in understanding why the program will not run on boot and why the 2nd one in the Crontab stops working after the pi is rebooted |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 4147 |
Using sudo means you're becoming the super user (aka root), so you are editing that user's crontab. nano should create a normal text file. Your problem could still be the trailing "&" char(s). It could also be whatever you put in /home/pi/programname.sh BTW You would NOT normally want root to run a user's script. Instead you would normally want that user to run the script i.e. you'd edit the user's crontab instead of using sudo. John |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3477 |
QUOTE=lew247]I've never got anything working in .etc/rc.local aparently it doesn't work so well in the latest Buster and onwards that's why I was trying Crontab Still works for me in /etc/rc.local in Buster; cat /etc/os-release shows VERSION="10 (buster)" VERSION_CODENAME=buster Don't know why it wouldn't work for you. I've never gotten "@boot" or the like to work in crontab (but not sure I've tried on a pi because /etc/rc.local has worked). One gotcha I've seen in crontab--a script or program can run perfectly from the prompt, but fails in crontab because different ash/bash/etc. or different directory or whatever. Can be perplexing. Can you be sure that is it is not actually starting to run, but failing because of one of those issues? Here's the relevant part of my /etc/rc.local (the "&" makes the program persist). # following turns off history expansion set +H /home/pi/udplisten.sh& /home/pi/udplisten16523.sh& #/home/pi/udplisten44.sh& /home/pi/tcplisten44.sh& exit 0 And a grepped list of running programs: > ps -A -f | grep listen root 511 1 0 2020 ? 00:00:59 /bin/bash /home/pi/udplisten.sh root 512 1 0 2020 ? 00:00:00 /bin/bash /home/pi/tcplisten44.sh root 516 512 0 2020 ? 00:00:00 /bin/bash /home/pi/tcplisten44.sh root 3246 511 0 17:56 ? 00:00:00 /bin/bash /home/pi/udplisten.sh pi 3436 1596 0 17:58 pts/3 00:00:00 grep --color=auto listen pi 4060 1 0 2020 ? 00:00:00 /bin/bash /home/pi/udplisten16523.sh pi 4062 4060 0 2020 ? 00:00:00 /bin/bash /home/pi/udplisten16523.sh Edited 2021-02-20 08:00 by lizby PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 4147 |
It probably is one of those. Best to show what's in that .sh file, but I suspect the problem will be running it as root when it should almost for sure be run as the user. John Edited 2021-02-20 07:59 by JohnS |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 8296 |
In Buster won't you have to use systemd or something? Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| Rado Regular Member  Joined: 27/11/2020 Location: CroatiaPosts: 59 |
The glorious invention that systemd is(*), it does not guarantee the ancient behaviour of rc.local script (to execute as the very last during the init), so there's no guarantee that the script started from there will not start before some other dependency is still inactive, and that might result in that script failing. One simple and stupid solution is to add some seconds of sleep at the beginning of rc.local, to give time for sluggish services to come alive. The same trick can be used in crontab, as there might be services that had no time to start before the user logged in (automatically). Solved in a similar way: @reboot sleep 60 && /home/user/my_special_script.sh Your script will execute 60 seconds after the cron has run the job, that should be ample time for any dependency to come to life. (*) I have no intention to start another systemd war in this forum, so let's just accept that I'm a grumpy old sysadmin who can not cope with the glorious wonders of modern times and superb architectures. |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3477 |
Good explanation, Rado--thanks. I've added sleep 30 to the beginning of my /etc/rc.local (though I've never found that my scripts were not working). PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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| lew247 Guru Joined: 23/12/2015 Location: United KingdomPosts: 1702 |
@reboot sh /home/pi/myprogram.sh/home/pi/logs/cronlog 2>&1[/QUOTE in my crontab This is the error log [CODEpi@Pi-Weather4:~/logs $ cat cronlog python3: can't open file 'myprogram.py': [Errno 2 No suchgured out how to add logs I have in my crontab This is the error log pi@Pi-Weather4:~/logs $ cat cronlog python3: can't open file 'myprogram.py': [Errno 2] No such file or directory I don't understand why it's changed the file name I also tried and get the same result I can run the program by typing ./myprogram.sh or sh myprogram.sh so it should work Edited 2021-02-20 21:14 by lew247 |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3477 |
Where does python3 come from? Does your script try to execute a python script? Perhaps we need to see myprogram.sh. Note that any file referred to in the myprogram.sh should have a full path. What's the smallest script that illustrates the problem? (Given that the log seems to indicate that crontab tried to execute the @reboot command line.) PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 4147 |
We need to see /home/pi/myprogram.sh I think it will be relying on PATH but you haven't set it to the right one (or at all), bearing in mind you are (or look to be) running as root when you probably do not want that. John Edited 2021-02-20 23:27 by JohnS |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3477 |
Re what John is saying, have you tried it with "crontab -e" rather than "sudo crontab -e"? The latter may be getting you into trouble with executing as root's crontab rather than the "pi" user crontab. PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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| lew247 Guru Joined: 23/12/2015 Location: United KingdomPosts: 1702 |
Got it working perfectly now thanks everyone I had to use a .desktop File as it's a graphics program and needed the X server to finish initializing before running |
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| lew247 Guru Joined: 23/12/2015 Location: United KingdomPosts: 1702 |
This is Python so not everyone will be able to but Could anyone that knows Linux and Matplotlib help me out? I need to learn how to import a data set from a csv file and display it in Matplotlib on the Pi Ideally I need to learn how to make a graph that will read the data from the first row which is the header and has the colum names Then use the data in the rows to make the plot There are 3 to start with , temp hightemp and low temp Eventually I'll be expanding this to use others and sub plots but I need to learn how to do this simple one first I've learnt how to get readings of my weather station at set times during the day and save them to a csv file with headers I've learnt how to make a Matplotlib with the data and make a graph that shows the data This was just a simple one with some data points  What I want to learn is how to import data from the csv file attached* and use that data to plot the graph data.zip It has 4 columns Day, Temp, Temphigh, TempLow and the rows have the data for various times throughout the day I want to graph I know it won't look brilliant and using a bar graph would be a better option but I couldn't figure out how to get that working with more than one data set So if anyone could help me by telling me how to use the data in the csv file to make the (bar)graph by reading the csv I'd be extremely grateful I can figure out other stuff once I know how to read the data and use it in matplotlib I did watch several videos and tutorials online but none actually helped as they weren't the same as what I want to do |
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