ssh user@225.225.225.1 -i ~/.ssh/some_key.pem

sudo update-alternatives --set php /usr/bin/php8.0
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.9 2

ln -s /opt/foo /usr/bin/bar

sudo apt install php-xdebug
sudo phpenmod -v 7.3 xdebug

redis-cli -a redispass
config set requirepass ""

sudo apt-get --purge remove octave3.2

dpkg -l OR apt list
dpkg -l | grep apt # SEARCH "apt"

sudo apt install apt-transport-https=1.4.10

scp root@servername.com:/tmp/1.sql ~/Downloads/1.sql  # Download
scp ~/1.sql root@servername.com:/tmp                  # Upload

pstree                                                # Tree
htpp                                                  # Informative

tree -L 4 dir_name

(npm run start&)

sudo xkill                                             # Interactive kill 
sudo kill -9 $(sudo lsof -t -i:9001)                   # Kill by port
sudo kill -9 1234                                      # Kill by pid

tar -xf archive.tar.gz