This is a compilation of ways of fixing shit on linux. I made it because, since I don’t use them on a daily basis, when I do need them I have usually forgotten and sometimes it is hard to find them again (because search engines keep sucking more and more).

TCP Ports

If you need to use a port, but it is already in use, you can do the following.

sudo netstat -tunlp      # returns all the PID currently in use by the system
sudo lsof -i TCP:3306    # returns the PID of the program using port 3306

Now you can evaluate if the process occupying that port matters or not. If it doesn’t you can kill it using the processing doingsudo kill -9 $PID.

Instaling Packages

Example: mysql-server installation fails.

# Remove all packages related to mysql-server
sudo apt-get purge mysql*
sudo apt-get remove --purge mysql*
sudo apt-get purge msql*
sudo apt auto-remove mysql*
sudo apt-get autoclean
sudo apt-get remove dbconfig-mysql 

# Remove any left over from the installation (if there are)
sudo vim /etc/apt/apt.conf.d
sudo apt-get remove dbconfig-mysql

# Make sure we don't have any mysql installed
dpkg -l | grep mysql

# Update the system
sudo apt update
sudo apt upgrade
sudo apt-get dist-update

# Attempt to install it again
sudo apt install mysql-server
sudo apt install mysql_secure_installation

I Botched My GRUB