Boot/Shutdown script automation

Shell Programming and Scripting
1

Looking to automate some commands to run at boot and poweroff in a startup/shutdown script.
How do I place it on the system so that it will be run automatically?

I don't want to use cron, not quite specific enough, random times when I may boot or shutdown.

---------- Post updated at 10:47 PM ---------- Previous update was at 10:07 PM ----------

Solved, halfway, someone who posted a solution and then took it down (??).
Can run stuff on startup, just looking for the shutdown equivalent.

man 5 crontab

Code:
---------
string meaning
------ -------
@reboot Run once, at startup.
@yearly Run once a year, "0 0 1 1 *".
@annually (same as @yearly)
@monthly Run once a month, "0 0 1 * *".
@weekly Run once a week, "0 0 * * 0".
@daily Run once a day, "0 0 * * *".
@midnight (same as @daily)
@hourly Run once an hour, "0 * * * *".
---------

***************

3

I posted, then removed that, but only because I misread your post (about not wanting to use cron).

Which OS are you using?

4

Ah right, I did wonder lol.
Yeah I didn't realise cron had that option, so that's good for the startup section that I need, just need to get an equivalent for shutdown.

Ubuntu 10.4 32-bit

---------- Post updated at 11:22 PM ---------- Previous update was at 10:55 PM ----------

Think this may be the way forward...

Customizing the Linux bootup and shutdown processes | TechRepublic

5

Yes. That article explains it well.

You can still use the cron @reboot option to start the script on reboot if the script stops itself when terminated (i.e. when the system shuts down).

i.e. with no bells or whistles a very simple "daemon"

# /my/script
LOG=/some/logfile

trap 'echo Terminated >> $LOG; exit #do some shutdown stuff here' 0

{
  while :; do
    # do something here
    sleep 60
  done
} 2>&1 >> $LOG

crontab -l
@reboot /my/script
6

Can I make a bash script and stick it in one of the rc* directories?
Which is best to put it in, higher or lower (0/5)?
This is what I was thinking:

/etc/rc0.d/S99myscript

So that it runs after the system has set itself up so my alterations aren't corrected as soon as they are made.

7

Normally you would be using runlevel 3.

runlevel
who -r

That would be the place to put it. Runlevel 0 is entered when halting the system.

The script would typically go into /etc/init.d, and have a link in /etc/rc.d/rc0.d and /etc/rc.d/rc3.d as Knn and Snn for Kill and Start, where nn is a number that determines the sequence during startup / shutdown the script is run.

ln -s /etc/init.d/myScript /etc/rc.d/rc3.d/S99myscript
ln -s /etc/init.d/myScript /etc/rc.d/rc0.d/K99myscript
8

I get the S/K part, but from what I see the 'nnnn' (x4) that you specified is different to my system and the article which has only 'nn' (x2).

That just your OS?

9

No, just a typo! But the number of digits is not important, except for the purposes of sorting. Scripts are run in the order given by:

for i in /etc/rc$runlevel.d/S* ; do

and

for i in /etc/rc$runlevel.d/K* ; do

during startup and shutdown.

10

Ok cool, cheers mate, thanks for the help, much appreciated.