====== Server administration ======

<code bash>
#! /bin/sh

for ip in echo `grep Ban /var/log/fail2ban.log | awk '{print $NF}' | sort | uniq`
do
    for email in `whois $ip | perl -wne'while(/[\w\.\-]+@[\w\.\-]+\w+/g){print "$&\n"}' | sort | uniq`
    do
        echo "Sending email to $email ..."
        echo "Hi,

The IP $ip has just been banned.
Here are more information about $ip:


`whois $ip`


Regards," | mail -s "$ip banned" $email;
    done
done
</code>

====== apt and dpkg ======

<code bash>
dpkg -l |awk '/^rc/ {print $2}' | xargs sudo dpkg --purge
</code>