Linux

sudo fdisk -l
#now identify EFI and linux partitions and set them here
#e.g.:
EFI=/dev/nvme0n1p1
LIN=/dev/nvme0n1p6

sudo apt -y install grub-efi
sudo mkdir /media/root && sudo mount $LIN /media/root
sudo mkdir /media/efi && sudo mount $EFI /media/efi
sudo grub-install --target=x86_64-efi $EFI --efi-directory=/media/efi --boot-directory=/media/root/boot

Newer versions of Kubuntu are missing the advanced mouse options which let you debounce the mouse

sudo apt install xserver-xorg-input-evdev
sudo mkdir -p /etc/X11/xorg.conf.d

Then edit /etc/X11/xorg.conf.d/xorg.conf

and append:

Section "InputClass"
    Identifier "evdev-mouse"
    MatchIsPointer "yes"
    Driver "evdev"
EndSection

You may have to reboot at this point

If the system has been corrupted, and there is no grub menu, then boot from a live CD, open a terminal and do this:

tar -cvjSf filename.tar.bz2 foldername
-c create
-v verboase
-j bzip2
-S Sparse files handled efficiently
-f filename

To securely wipe a hard drive of all data, do:

apt install wipe
shred -vfz -n 2 /dev/sdb

• Options above are verbose, force, zero out in an extra pass
• Number of passes: -n 2

An alternative “light” way of doing this is to simply copy random bytes

See user manual here: www.gnu.org/…escue_manual.html

• List current tables with line numbers and stats

iptables -L INPUT --line-numbers -v

• Append another rule

iptables -A INPUT -s 58.245.23.126/24 -j DROP

• Delete rule #3

iptables -D INPUT 3

• The moment you apply IPTABLE rule it immediately becomes active.But it will not survive a reboot.
• To be able to survive IPTABLES a reboot in your network configuration file /etc/network/interfaces file (referring to a Debian/Ubuntu system) you need to add:

Undeleting a file is not easy in Linux.
However, if it's a text file, and you know a phrase from it, you can search the whole drive for the contents:
```
grep -a -C 200 -F "words in file" /dev/hda1 | more #change /dev/hda1 to whatever is appropriate
```