====== Bash ======
^ Function ^ Code ^
| Check storage | ''df -h'' |
| Check storage | ''du -hs foldername'' |
| Physical volumes | ''pvs'' |
| Remove | rm -rf sth |
| System usage monitor | ''htop'' |
| CPU information | ''lscpu'' |
| Check drives | ''lsblk'' |
| Check GPU | ''sudo lshw -C display'' / ''lspci | grep -e VGA'' |

===== - Building from source (with python) =====
<code bash>
cd software
mkdir build
cd build
cmake -D BUILD_WITH_PYTHON=ON -DCMAKE_INSTALL_PREFIX=<install_path> ..
sudo make install
export LD_LIBRARY_PATH=<install_path>/lib/:$LD_LIBRARY_PATH
export PYTHONPATH=<install_path>/lib/python3.11/site-packages:$PYTHONPATH
</code>

===== Ports =====
To kill everything listening to a port: ''%%sudo fuser -k 2121/tcp%%''

===== Profile =====
Create a hidden file called ''.bashrc'' in your home folder and add aliases for different commands as:

<code>
alias something='ssh -Y uder@server.com'
</code>

So ''something'' will always execute the command ''ssh -Y uder@server.com''.

===== Screen =====
  * Create a screen: ''screen -S name''
  * Detach from the screen with keyboard shortcut: ''ctrl+a d''
  * See a list of screens: ''screen -ls''
  * Attach to the desired screen: ''screen -r name''
  * Detach from outside (not needed usually): ''screen -d -r name''

===== Server =====
<code>
ssh -Y user@10.50.17.66 # login
ssh -N -f -L localhost:8889:localhost:8889 user@address # tunneling
</code>

Login to server using private key:
  - Create a private-public ssh key pair.
  - Your private key should be inside the folder ''~/.ssh/''
  - Change permission of the folder: ''sudo chmod -R 700 ~/.ssh''
  - Then log in: ''ssh -Y username@server''

==== Users and Groups ====
| Check permissions of a folder | ''ls -ld foldername'' |
| See all users of a group | ''grep groupname /etc/group'' |
| Give a user write permission to a folder using acl | ''setfacl -m u:username:rwx foldername'' |
| Change owner group of a folder | ''chown -R :groupname foldername'' |
| Change owner user of a folder | ''chown username: foldername'' |
| Change permissions of a folder | ''chmod -R u+w foldername'' / ''chmod -R 770 foldername'' |

<code>
sudo adduser username
sudo deluser username
sudo addgroup groupname
sudo delgroup groupname
sudo adduser username groupname
getent passwd | cut -d: -f1
getent group
</code>

===== Storage =====
<code>
sudo mount -t auto /dev/sdb /media/plato/
</code>

===== GPU =====
<code bash>
sudo apt autoremove nvidia* --purge
sudo /usr/bin/nvidia-uninstall
sudo /usr/local/cuda-X.Y/bin/cuda-uninstall
sudo apt update
sudo apt upgrade
lspci | grep -e VGA
ubuntu-drivers devices
sudo ubuntu-drivers autoinstall
reboot
nvidia-smi
</code>

===== IP setting =====
<code bash>
ip link
sudo nano /etc/netplan/*.yaml
</code>

Create the yaml file the following way:
<code bash>
# This is the network config written by 'subiquity'
network:
  version: 2
  renderer: networkd
  ethernets:
    eno1:
      dhcp4: no
      addresses: [10.50.255.33/27]
      gateway4: 10.50.255.62
      nameservers:
          addresses: [8.8.8.8]
    eno2:
      dhcp4: no
  version: 2
</code>