Linux Remote shutdown script?

There, finished v0.1

First, remove all of the previous script (crontab, log, script itself, the various files it created,...)

And then, issue this:

Code:

sudo su
cd
mkdir -p scripts
wget http://glider.sin.khk.be/ActivityShutdown.sh -O /root/scripts/ActivityShutdown.sh
chmod u+x /root/scripts/ActivityShutdown.sh

crontab -e

Add to the crontab file:

Code:

*/20 * * * * sh /root/scripts/ActivityShutdown.sh

Save and exit and hope for the best...

 

EDIT: I was writing this post before Glider's reply and as such didn't see it until afterwards

Hi guys, thanks again for the help.

Um, the typo with the script might have been where I was playing around getting it to work.

But, good news:

I got up early this morning, went for a run and came back to it with a fresh mind. I deleted my script, my entry in the crontab and basically anything that I'd edited so far and started afresh. I'm glad to say it seems to be working fine now! I'll just go through the steps quickly for anyone who's interested and maybe Glider or Fod can help me tidy it up a bit . My understanding of user rights is I think what, might have been the cause so if I list the exact steps, as I say, Glider and Fod might help me put it straight .

I first ran the command:

Code:

sudo nano powerOff

This creates a new blank script called "powerOff". I then entered the following bash script:

Code:

#!/bin/bash
#
# This is scheduled in CRON.  It will run every 20 minutes
# and check for inactivity.  It compares the RX and TX packets
# from 20 minutes ago to detect if they significantly increased.
# If they haven't, it will force the system to shutdown.
#

log=/root/scripts/idle/log

# Extract the RX/TX
rx=`/sbin/ifconfig eth0 | grep -m 1 RX | cut -d: -f2 | sed 's/ //g' | sed 's/errors//g'`
tx=`/sbin/ifconfig eth0 | grep -m 1 TX | cut -d: -f2 | sed 's/ //g' | sed 's/errors//g'`

#Write Date to log
date >> $log
echo "Current Values" >> $log
echo "rx: "$rx >> $log
echo "tx: "$tx >> $log

# Check if RX/TX Files Exist
if [ -f /root/scripts/idle/rx ] || [ -f /root/scripts/idle/tx ]; then
        p_rx=`cat /root/scripts/idle/rx`  ## store previous rx value in p_rx
        p_tx=`cat /root/scripts/idle/tx`  ## store previous tx value in p_tx

        echo "Previous Values" >> $log
        echo "p_rx: "$p_rx >> $log
        echo "t_rx: "$p_tx >> $log

        echo $rx > /root/scripts/idle/rx    ## Write packets to RX file
        echo $tx > /root/scripts/idle/tx    ## Write packets to TX file

        # Calculate threshold limit
        t_rx=`expr $p_rx + 1000`
        t_tx=`expr $p_tx + 1000`

        echo "Threshold Values" >> $log
        echo "t_rx: "$t_rx >> $log
        echo "t_tx: "$t_tx >> $log
        echo " " >> $log

        if [ $rx -le $t_rx ] || [ $tx -le $t_tx ]; then  ## If network packets have not changed that much
                echo "System shutting down, due to lack of network activity ..." >> $log
                echo " " >> $log
                rm /root/scripts/idle/rx
                rm /root/scripts/idle/tx
                /sbin/halt ## Shutdown
        fi

#Check if RX/TX Files Doesn't Exist
else
        echo $rx > /root/scripts/idle/rx ## Write packets to file
        echo $tx > /root/scripts/idle/tx
        echo " " >> $log
fi

With this entered I then pressed "ctrl+x" and saved the script.

I did:

Code:

sudo chmod 700 /root/powerOff

which I believe makes the script only able to run as root.

A quick:

Code:

sudo chmod a+x /root/powerOff

makes the script executable.

If you now run the script with:

Code:

sudo sh /root/powerOff

it will complain about the missing "script" and "idle" directories, as they haven't been created yet.

A quick:

Code:

sudo mkdir /root/scripts

followed by

Code:

sudo mkdir /root/script/idle

sorts that out.

I then did:

Code:

sudo chmod 755 -R /root/scripts

this means make the file accessible to all users (the -R means recursively or, in laymans terms, apply this rule to all subdirectories and files inside of /scripts)

Finally, I added the entry to the root crontab:

Code:

sudo crontab -e

open the existing crontab.

Simply add this to a new line:

Code:

*/30 * * * * sh /root/powerOff

and hit "ctrl+x" to save. (feel free to change the "30" for any other value fom 0-60, depending on how often you want it to check)

eh voila! Hopefully this can be of use to somebody else (Once Glider and Fod have done their thing to it ), especially in light of the ludicrous increase in energy prices recently

 

OMG! I feel awful

I'm really sorry you put all that work into it for me dude but I'm sure it's a damn site prettier than mine huh?

Your advice has been priceless for me (not just on this matter) and the amount of work/help that you're willing to supply to people on these forums should be applauded.

*tips hat* Thanks again Glider

 

This is more or less the same,yet different... chmod 700 sets Read, Write and eXecute for 'user' on the file, and a+x adds eXecute for all (user, group, others). So you'll end up with rwx--x--x as rights, rwx for user, and x for group and other.

Don't I don't mind writing scripts... And it just took me 10 minutes to write it... I think it's more logical (1 logfile for the entire script instead of lots of files scattered around...) but if it isn't broken, don't fix it and just use yours

 

It is more logical tbh (I just downloaded it and took a look). I have a habit of using others' code/scripts and being scared to change too much in case I "break" it. The thing is, I can write fairly good code (java/C/C++) so the bash script stuff really isn't that complicated and I should be more confident with it. There is definitely an element of "if it ain't broke, don't fix it" to that mentality but what about "if it ain't broke clean it up and make it more efficient" .

I'll leave it for now but when I come to setting my new file server (some 1TB drives on Raid 5) I'll be sure to dig up this post and use your (clearly superior) effort

Thanks again dude