25

I am new to Linux & looking forward to start application (which toggles a led every 10 sec). I have written the application program & it is working fine but now I want to start it automatically on boot.

The documentation here says to copy the startup script to the /etc/init.d directory and make a symbolic link to the copied script in the rc.d directory.

What should be the extension and name of these script files? Can we manually add the symbolic link in rc.d or is there some specific procedure for this?

Any suggestion how to achieve it?

  • The preferred way to add an init script to startup varies by distros. Some are even phasing them out in favor of upstart and systemd. I wouldn't recommend simply using "&" to background, as something like Debian's start-stop-daemon handles it better (although it preferable the program itself daemonizes). What distro are you using? Outside of desktop MIME types, file extensions are meaningless in *nix and its preferred that executables don't have one. – jordanm Nov 28 '12 at 4:54
  • If you are using petalogix, just follow that documentation - no special names required, just do as they say. Did you try it? What problems are you having? (If not, please specify your distro and explain what doesn't work with what you tried.) – Mat Nov 28 '12 at 5:14
  • I am using Debian “wheezy” for RPi. – gorge Nov 28 '12 at 6:12
  • 1
    if you need to do it approximately every 10 seconds (i.e. not 10 seconds sharp), you might want to use cron instead. – peterph Nov 28 '12 at 10:08
  • @peterph: but it sounds like the program toggles the LED every 10 seconds, not a program that is executed every 10 seconds. – Zorawar Nov 28 '12 at 13:47
19

Here's the excerpt from http://www.debian-administration.org/articles/28 which seems to answer your question.

Note: In the example script below just add a call to the "start)" section to actually launch your program. You can test the script's functionality without rebooting the system: call it with the full path and giving it a parameter of "start" or "stop"

Here goes:

Debian uses a Sys-V like init system for executing commands when the system runlevel changes - for example at bootup and shutdown time.

If you wish to add a new service to start when the machine boots you should add the necessary script to the directory /etc/init.d/. Many of the scripts already present in that directory will give you an example of the kind of things that you can do.

Here's a very simple script which is divided into two parts, code which always runs, and code which runs when called with "start" or "stop".

#! /bin/sh
# /etc/init.d/blah
#

# Some things that run always
touch /var/lock/blah

# Carry out specific functions when asked to by the system
case "$1" in
  start)
    echo "Starting script blah "
    echo "Could do more here"
    ;;
  stop)
    echo "Stopping script blah"
    echo "Could do more here"
    ;;
  *)
    echo "Usage: /etc/init.d/blah {start|stop}"
    exit 1
    ;;
esac

exit 0

Once you've saved your file into the correct location make sure that it's executable by running "chmod 755 /etc/init.d/blah".

Then you need to add the appropriate symbolic links to cause the script to be executed when the system goes down, or comes up.

The simplest way of doing this is to use the Debian-specific command update-rc.d:

root@skx:~# update-rc.d blah defaults
 Adding system startup for /etc/init.d/blah ...
   /etc/rc0.d/K20blah -> ../init.d/blah
   /etc/rc1.d/K20blah -> ../init.d/blah
   /etc/rc6.d/K20blah -> ../init.d/blah
   /etc/rc2.d/S20blah -> ../init.d/blah
   /etc/rc3.d/S20blah -> ../init.d/blah
   /etc/rc4.d/S20blah -> ../init.d/blah
   /etc/rc5.d/S20blah -> ../init.d/blah
  • do I have to actually place this script in etc/init.d/ or does the line at the top, # /etc/init.d/blah, indicate a location to the shell? – user137717 Jun 29 '16 at 14:54
  • I'm getting "-sh: update-rc.d: command not found" – m4l490n Jun 22 '17 at 19:57
  • 2
    Newer systems employ systemd for many things, including for bootup configuration. Use systemctl to control and configure systemd. – Alexander Shcheblikin Jul 10 '18 at 2:38
4

The best way is to check package source of your distribution for a regular system service, e.g. for OpenSSH - you'll see what the good practices are. After all, one of the reasons behind open-source is to be able to learn from the sources.

  • 1
    Excellent advice! Truly wise and relevant, and tuned to all the Distos. (And incidentally answers the "new to Linux" and the "how do I do it" part of the question. I will use this answer to improve my start stop scripts. – Bruce0 Apr 9 '17 at 15:48
3

Use Supervisor, an effective program that manages and logs the startup applications with arguments. Learn more from http://supervisord.org/running.html and (Follow the installation instruction.

Create a conf file at /etc/supervisor/conf.d/{PROGRAM_NAME}.conf and Here is the code,

[program:{PROGRAM_NAME}]
command=/usr/bin/{PROGRAM_NAME} -arg1 -arg2
autostart=true  
autorestart=true  
stderr_logfile=/var/log/supervisor/{PROGRAM_NAME}.err.log  
stdout_logfile=/var/log/supervisor/{PROGRAM_NAME}.out.log  

Then execute from cmd line:

supervisorctl reload

  • Whereas your answer is fine, I think you should change it to show that "supervisorctl reload " is to be executed from the CLI, not to be inserted in the .conf file – dlewin Mar 15 '18 at 16:45
3

Using crontab is much easier.

Use crontab -e to edit user's crontab.
Add following line at the end:

@reboot <command>

Examples:

  • @reboot my_script.sh
  • @reboot python my_script.py arg1 arg2

Finally use crontab -l to make sure your script was added to the list.

  • I wonder why this answer received downvotes? Seems like a very simple solution, and one that uses crontab - which probably everyone knows and understands already. – kolinko Apr 19 at 16:52
1

Newer versions of linux support systemd (as @AlexanderShcheblikin said). It has more features and is more portable than debian-specific solution.

Please read this really great guide.

Here is a quick reference of the bare minimum needed:

  1. A script (e.g. myscript.sh) with executable permissions.
  2. A Unit file (e.g. myservice.service) with ".service" extension in /etc/systemd/system with 644 permissions that contains the command to execute the script. For example,

:

[Unit]
Description=Example systemd service.

[Service]
Type=simple
ExecStart=/bin/bash /path/to/myscript.sh

[Install]
WantedBy=multi-user.target
  1. Run the command sudo systemctl enable myservice to enable it to start on boot.

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