Run skript on shutdown and restart

Question

Based on some posts here, I try to run a simple script to clean up a folder with temporary content on restart and shutdown.

Following the instructions and the READMEs I wrote this script:

/etc/init.d/cleantmp

#!/bin/sh
### BEGIN INIT INFO
# Provides:          cleantmp
# Required-Start:
# Required-Stop:     $local_fs
# Default-Start:
# Default-Stop:      0 1 6
# Short-Description: clean temporary folders
# Description:
### END INIT INFO

PATH=/sbin:/usr/sbin:/bin:/usr/bin

echo "Clean up temporary folders"
rm -rf /home/user/tmp/*

Then I gave it the execution rights:

$ sudo chmod +x /etc/init.d/cleantmp
$ ls -l /etc/init.d/cleantmp 
-rwxr-xr-x 1 root root 329 Dec 19 12:50 /etc/init.d/cleantmp

Then I update the rc:

$ sudo update-rc.d cleantmp defaults
$ ls -l /etc/rc?.d/*cleantmp 
lrwxrwxrwx 1 root root 18 Dec 19 13:12 /etc/rc0.d/K01cleantmp -> ../init.d/cleantmp
lrwxrwxrwx 1 root root 18 Dec 19 13:12 /etc/rc1.d/K01cleantmp -> ../init.d/cleantmp
lrwxrwxrwx 1 root root 18 Dec 19 13:12 /etc/rc6.d/K01cleantmp -> ../init.d/cleantmp

So far so good. But after shutdown and start or a reboot, the temporary files still exist. If I directly call one of the symlinks using sudo the files correctly disappear.

What is wrong here?

---

OS: Linux 4.4.0-104-generic #127-Ubuntu | Ubuntu Gnome 16.04.3 LTS 64-bit

Answer 1

There are three significant things wrong:

• You wrote a van Smoorenburg rc script, when Ubuntu 16 is a systemd operating system and is in fact on its second init system since using van Smoorenburg rc over a decade ago. Don't begin with van Smoorenburg rc if you are doing new stuff on Ubuntu Linux.
• You wrote a van Smoorenburg rc script badly, not following the instructions or the example in init-d-script(5) manual page. Your rc script does not properly respond to the various subcommands that such scripts are called with, for starters, or source the Debian/Ubuntu standard functions library.
• You got the LSB headers wrong.

On the principle of not beginning with stuff that is more than a decade out of date on Ubuntu Linux in the first place, throw this away.

• Write yourself a clean-user-tmp.conf file in /etc/tmpfiles.d, or
• write yourself an /etc/systemd/system/clean-user-tmp.service something like

  [Unit]
  Documentation=https://unix.stackexchange.com/a/411804/5132
  Description=Remove ~user/tmp/
  [Service]
  User=user
  ; Common mistakes to avoid: 
  ;   expecting * or ~ to be expanded
  ;   not using an absolute pathname for the command
  ; Substitute /bin/rm if you do not have safe-rm installed.
  ExecStart=/usr/bin/rm -r -f -- ${HOME}/tmp/
  [Install]
  WantedBy=multi-user.target

  and enable it with

  systemctl enable clean-user-tmp.service

  , or
• write yourself a /home/user/.local/share/systemd/user/clean-tmp.service and enable it with

  systemctl --user enable clean-tmp.service

  .

Further reading

• https://unix.stackexchange.com/a/480897/5132