Linux oft-required commands(for self reference)

Install and export JAVA_HOME:

apt-get update
sudo apt install default-jdk

 which java

Output: /usr/bin/java

readlink -f /usr/bin/java

Output: /usr/lib/jvm/java-11-openjdk-amd64/bin/java

export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64

Find files containing text:

find . -type f -exec grep -H '8080' {} \;

Remove all stopped docker containers

docker rm $(docker ps -a-q)