can't connect to mysql server through socket /var/run/mysqld/mysqld.sock ubuntu 18.04 code example

Example 1: can't connect to local mysql server through socket '/var/run/mysqld/mysqld.sock'

# this saved my ass
# first  you must perform a graceful shutdown of the server from the command line rather than powering off the server
shutdown -h now

# an additional method for getting it back up again when you run into this problem is to move mysql.sock

# to centos
mv /var/lib/mysql/mysql.sock /var/lib/mysql/mysql.sock.bak

# to ubuntu
mv /var/run/mysqld/mysqld.sock /var/run/mysqld/mysqld.sock.bak

# restart mysql
service mysqld start

Example 2: how to connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

#/usr/sbin/mysqld --defaults-file=/etc/mysql/my.cnf --basedir=/usr --datadir=/var/lib/mysql --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock