How do we launch a program at startup

**schmitta** · May 6th, 2021

I am running server 21.04 on a raspberry pi. I need to run a script at powerup. The machine now does a autologin but I am unable to get @reboot sh ~/rpi/startrpi.sh to run. I need a program to run all the time the system is up to display data to the user and to log the data. I need the data to display on the terminal which I believe runs on tty1. I have tried crontab, getty and other suggestions given on the internet and have worked several weeks with no luck. I can't use the raspberry pi Linux as they have crippled ability for a program to run at powerup for their own reasons. That is why I am on ubuntu server. I am running a RPi 3B. Any help would be greatly appreciated.

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.

**scorp123** · May 6th, 2021

Originally Posted by schmitta

maybe I should write a deamon to do this?

You could define your own system service?

Create a service definition in /etc/systemd/system ... you need to be superuser "root" to do this. So you need to use "sudo" + an editor, e.g.

Code:

sudo gedit /etc/systemd/system/serial-term.service
OR:
sudo vim /etc/systemd/system/serial-term.service
OR:
sudo nano /etc/systemd/system/serial-term.service

(... whichever editor works for you and you are comfortable with ...)

Content could be something like this:

Code:

[Unit]
Description=Serial-Terminal
Requires=network.target
After=systemd-user-sessions.service

[Service]
Type=simple
Restart=always
# Please edit the line below as needed.
# Use the full path to the program you wish to run
ExecStart=/full/path/to/the/term/program
# If you leave "User=" away then superuser "root" will be used.
# The user you use here MUST HAVE permission to run the program
# AND the permission to access / read / write to the serial device.
# Either create such a user or use "root".
User=mytermserviceuser

[Install]
WantedBy=multi-user.target

Once that's done you can tell "systemctl" to reload all its service definitions:

Code:

sudo systemctl daemon-reload

If there's no error message it means this was a success.

Now you can enable and start the service:

Code:

sudo systemctl enable serial-term.service
sudo systemctl start serial-term.service

You can check if it has worked by e.g.:

Code:

sudo systemctl status serial-term.service

You can investigate errors e.g. by:

Code:

sudo journalctl -xe

**LHammonds** · May 6th, 2021

Originally Posted by schmitta

I am running server 21.04 on a raspberry pi. I need to run a script at powerup. The machine now does a autologin but I am unable to get @reboot sh ~/rpi/startrpi.sh to run. I need a program to run all the time the system is up to display data to the user and to log the data. I need the data to display on the terminal which I believe runs on tty1. I have tried crontab, getty and other suggestions given on the internet and have worked several weeks with no luck. I can't use the raspberry pi Linux as they have crippled ability for a program to run at powerup for their own reasons. That is why I am on ubuntu server. I am running a RPi 3B. Any help would be greatly appreciated.

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.

The problem is in your script. You should not reference relative paths...they can change...especially depending on which user account it is being run under. There also should not be a trailing slash after "bash"

You did not mention which user is running the crontab schedule. I will assume root.

Code:

crontab -e -u root

Code:

# Crontab SYNTAX:
#       __________ Minute (0-59)
#      / _________ Hour (0-23)
#     / /  _______ Day Of Month (1-31)
#    / /  /   ____ MONth (1-12)
#   / /  /   /   _ Day Of Week (0-7) (Sun = 0 or 7)
#  / /  /   /   /  -------------------------------------------------------------
# m h dom mon dow  command <arguments> > /dev/null 2>&1

@reboot /root/rpi/startrpi.sh

/root/rpi/startrpi.sh

Code:

#!/bin/bash
cd /root/rpi
exec /root/rpi/term

NOTE: You probably do not need the "change directory" command in the script but if your term application is using relative paths too, it "might" be necessary.

**schmitta** · May 7th, 2021

changed it to your way. did a sudo reboot on the raspberry pi and nothing came out even though the hardware before the rpi indicated data was being sent to it.

**schmitta** · May 7th, 2021

did it your way and got the following:

Code:

ubuntu@ubuntu:~$ sudo systemctl daemon-reload
ubuntu@ubuntu:~$ sudo systemctl enable serial-term.service
Created symlink /etc/systemd/system/multi-user.target.wants/serial-term.service → /etc/systemd/system/serial-term.service.
ubuntu@ubuntu:~$ sudo systemctl start serial-term.service
ubuntu@ubuntu:~$ sudo systemctl status serial-term.service
● serial-term.service - Serial-Terminal
     Loaded: loaded (/etc/systemd/system/serial-term.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Fri 2021-05-07 01:14:46 UTC; 1min 3s ago
    Process: 2251 ExecStart=/home/ubuntu/rpi/term (code=exited, status=217/USER)
   Main PID: 2251 (code=exited, status=217/USER)


May 07 01:14:46 ubuntu systemd[1]: serial-term.service: Scheduled restart job, restart counter is at 5.
May 07 01:14:46 ubuntu systemd[1]: Stopped Serial-Terminal.
May 07 01:14:46 ubuntu systemd[1]: serial-term.service: Start request repeated too quickly.
May 07 01:14:46 ubuntu systemd[1]: serial-term.service: Failed with result 'exit-code'.
May 07 01:14:46 ubuntu systemd[1]: Failed to start Serial-Terminal.
ubuntu@ubuntu:~$

examined the journal and got:

ubuntu@ubuntu:~$ sudo journalctl -xe
░░ Defined-By: systemd
░░ Support: http://www.ubuntu.com/support
░░
░░ A stop job for unit serial-term.service has finished.
░░
░░ The job identifier is 1375 and the job result is done.
May 07 01:14:46 ubuntu systemd[1]: serial-term.service: Start request repeated too quickly.
May 07 01:14:46 ubuntu systemd[1]: serial-term.service: Failed with result 'exit-code'.
░░ Subject: Unit failed
░░ Defined-By: systemd
░░ Support: http://www.ubuntu.com/support
░░
░░ The unit serial-term.service has entered the 'failed' state with result 'exit-code'.
May 07 01:14:46 ubuntu systemd[1]: Failed to start Serial-Terminal.
░░ Subject: A start job for unit serial-term.service has failed
░░ Defined-By: systemd
░░ Support: http://www.ubuntu.com/support
░░
░░ A start job for unit serial-term.service has finished with a failure.
░░
░░ The job identifier is 1375 and the job result is failed.
May 07 01:15:49 ubuntu sudo[2252]:   ubuntu : TTY=pts/0 ; PWD=/home/ubuntu ; USER=root ; COMMAND=/usr/bin/systemctl sta>
May 07 01:15:49 ubuntu sudo[2252]: pam_unix(sudo:session): session opened for user root by ubuntu(uid=1000)
May 07 01:15:51 ubuntu sudo[2252]: pam_unix(sudo:session): session closed for user root
May 07 01:17:01 ubuntu CRON[2258]: pam_unix(cron:session): session opened for user root by (uid=0)
May 07 01:17:01 ubuntu CRON[2259]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
May 07 01:17:01 ubuntu CRON[2258]: pam_unix(cron:session): session closed for user root
May 07 01:18:42 ubuntu sudo[2265]:   ubuntu : TTY=pts/0 ; PWD=/home/ubuntu ; USER=root ; COMMAND=/usr/bin/journalctl -xe
May 07 01:18:42 ubuntu sudo[2265]: pam_unix(sudo:session): session opened for user root by ubuntu(uid=1000)
lines 4797-4825/4825 (END)

I did all the previous by ssh ubuntu@10.0.0.14

Looked at the crt output for the RPI and nothing was printing.

did a sudo reboot directly on the RPI and a red [failed] displayed on the crt during boot for the Serial-Terminal

nothing printed after the boot.

looked at the journalctl and got;

ubuntu@ubuntu:~$ sudo journalctl -xe
░░
░░ The unit systemd-fsckd.service has successfully entered the 'dead' state.
May 07 01:23:36 ubuntu systemd[1]: systemd-hostnamed.service: Succeeded.
░░ Subject: Unit succeeded
░░ Defined-By: systemd
░░ Support: http://www.ubuntu.com/support
░░
░░ The unit systemd-hostnamed.service has successfully entered the 'dead' state.
May 07 01:27:18 ubuntu sshd[2040]: Accepted password for ubuntu from 10.0.0.119 port 53098 ssh2
May 07 01:27:18 ubuntu sshd[2040]: pam_unix(sshd:session): session opened for user ubuntu by (uid=0)
May 07 01:27:18 ubuntu systemd-logind[1693]: New session 5 of user ubuntu.
░░ Subject: A new session 5 has been created for user ubuntu
░░ Defined-By: systemd
░░ Support: http://www.ubuntu.com/support
░░ Documentation: sd-login(3)
░░
░░ A new session with the ID 5 has been created for the user ubuntu.
░░
░░ The leading process of the session is 2040.
May 07 01:27:18 ubuntu systemd[1]: Started Session 5 of user ubuntu.
░░ Subject: A start job for unit session-5.scope has finished successfully
░░ Defined-By: systemd
░░ Support: http://www.ubuntu.com/support
░░
░░ A start job for unit session-5.scope has finished successfully.
░░
░░ The job identifier is 1194.
May 07 01:27:40 ubuntu sudo[2118]:   ubuntu : TTY=pts/0 ; PWD=/home/ubuntu ; USER=root ; COMMAND=/usr/bin/journalctl -xe
May 07 01:27:40 ubuntu sudo[2118]: pam_unix(sudo:session): session opened for user root by ubuntu(uid=1000)
lines 4911-4939/4939 (END)

Thank you for your help -- still need help.

**schmitta** · May 7th, 2021

Code:

rebooted daemons 
enabled and started serial-term.service
looked at status and got
ubuntu@ubuntu:~$ sudo systemctl status serial-term.service
● serial-term.service - Serial-Terminal
     Loaded: loaded (/etc/systemd/system/serial-term.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Fri 2021-05-07 01:37:12 UTC; 29s ago
    Process: 2215 ExecStart=/home/ubuntu/rpi/term (code=exited, status=217/USER)
   Main PID: 2215 (code=exited, status=217/USER)


May 07 01:37:12 ubuntu systemd[1]: serial-term.service: Scheduled restart job, restart counter is at 5.
May 07 01:37:12 ubuntu systemd[1]: Stopped Serial-Terminal.
May 07 01:37:12 ubuntu systemd[1]: serial-term.service: Start request repeated too quickly.
May 07 01:37:12 ubuntu systemd[1]: serial-term.service: Failed with result 'exit-code'.
May 07 01:37:12 ubuntu systemd[1]: Failed to start Serial-Terminal.
ubuntu@ubuntu:~$


looked at the journalctl and got

ubuntu@ubuntu:~$ sudo journalctl -xe
░░
░░ The job identifier is 1807 and the job result is failed.
May 07 01:37:33 ubuntu systemd[1]: Starting Cleanup of Temporary Directories...
░░ Subject: A start job for unit systemd-tmpfiles-clean.service has begun execution
░░ Defined-By: systemd
░░ Support: http://www.ubuntu.com/support
░░
░░ A start job for unit systemd-tmpfiles-clean.service has begun execution.
░░
░░ The job identifier is 1894.
May 07 01:37:33 ubuntu systemd[1]: systemd-tmpfiles-clean.service: Succeeded.
░░ Subject: Unit succeeded
░░ Defined-By: systemd
░░ Support: http://www.ubuntu.com/support
░░
░░ The unit systemd-tmpfiles-clean.service has successfully entered the 'dead' state.
May 07 01:37:33 ubuntu systemd[1]: Finished Cleanup of Temporary Directories.
░░ Subject: A start job for unit systemd-tmpfiles-clean.service has finished successfully
░░ Defined-By: systemd
░░ Support: http://www.ubuntu.com/support
░░
░░ A start job for unit systemd-tmpfiles-clean.service has finished successfully.
░░
░░ The job identifier is 1894.
May 07 01:37:42 ubuntu sudo[2217]:   ubuntu : TTY=pts/0 ; PWD=/home/ubuntu ; USER=root ; COMMAND=/usr/bin/systemctl sta>
May 07 01:37:42 ubuntu sudo[2217]: pam_unix(sudo:session): session opened for user root by ubuntu(uid=1000)
May 07 01:37:44 ubuntu sudo[2217]: pam_unix(sudo:session): session closed for user root
May 07 01:40:07 ubuntu sudo[2226]:   ubuntu : TTY=pts/0 ; PWD=/home/ubuntu ; USER=root ; COMMAND=/usr/bin/journalctl -xe
May 07 01:40:07 ubuntu sudo[2226]: pam_unix(sudo:session): session opened for user root by ubuntu(uid=1000)
lines 4871-4899/4899 (END)

note that this will be located 300 miles away so I will not be able to reboot the daemons or use systemctl

**schmitta** · May 7th, 2021

I need to do two things. Display the data on the linux crt and log the data to disk. I have software that does this when I load and run it on the linux crt. The os is a ubuntu server so there is no gui; no terminal you can enter bash commands when the system stops loading on the crt and keyboard. What I need to do is execute a script on tty1 that runs my software. How do I do that? I am not an expert on linux. can the daemon execute a script ? What should I do to accomplish the above?

**schmitta** · May 7th, 2021

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!!!!