need to autorun a program at startup on ubuntu server 21.04

schmitta · 05-04-2021, 10:17 PM

I need to autorun a program at startup on ubuntu server 21.04 . I have worked on this for days with no result. I tried @reboot but it does not work. I tried to look at the logs but did not find anything or error messages. I want to run a bash script (.sh) that cd to a folder and then runs a c program. The machine I am running on is a raspberry pi 3B. it is holding up my project that I need to install. Thank you for your help.

ondoho · 05-05-2021, 12:37 AM

Quote:

Originally Posted by schmitta

I tried @reboot but it does not work.

"does not work" is never a good problem sdescription.
What exactly did you try there?

What sort of program is this? GUI or no-GUI? What sort of privileges does it require?
...

I believe you are looking for a systemd service.

schmitta · 05-05-2021, 08:32 PM

I tried:
@reboot sh ~/rpi/startrpi.sh

to get a script to execute

the script is:

#!/bin/bash/
cd ~/rpi
exec ./term

term is a C program that takes what comes in from a USB RS232 and prints it out on tty1

./term does work

I am trying to display information to the user on tty1 after the system boots up

./term is to run continuously while the system is up

maybe I should write a deamon to do this?

thank you for helping me.

schmitta · 05-05-2021, 08:47 PM

This is ubuntu server 21.04 running on a raspberry pi 3B

this is a non gui program

michaelk · 05-05-2021, 08:53 PM

cron jobs are not associated with a terminal display and therefore no output will appear regardless if the job runs.

Does the Pi auto login? If so you can start the program from your bash_rc ( I think?)

schmitta · 05-06-2021, 12:02 AM

I was able to get it to autologin additional info would be welcome. I will lookup bash_rc

ondoho · 05-06-2021, 12:22 AM

@michaelk: is the stuff from post #3 recognizable to someone who uses cron?
I understand the basic requirement but I have no idea what OP is on about.

shruggy · 05-06-2021, 01:35 AM

@ondoho. Well, @reboot is part of crontab specification. It's recognized both by Vixie cron and cronie.

scasey · 05-06-2021, 02:05 AM

Um. cron doesn’t know from ~ *
Use the absolute path to the script

Code:

@reboot sh /home/user/rpi/startrpi.sh

*well technically it does, but it’s not going to be the same home directory as that in which the script resides.

schmitta · 05-07-2021, 06:38 AM

I got it to work

I added my script to the end of ~/.bashrc and it executed it and printed on the terminal

i.e.

to /home/ubuntu/.bashrc I added at the end

/home/ubuntu/rpi/startrpi.sh

and the program started to execute. it also executes when I ssh in to the raspberry pi. I
can stop it by cntl+C and then get my work done. Praise GOD!!!!