I am going to answer it one by one.
1 You can get MySQL prompt in Linux using:
mysql -u root -p
At the Enter password: please enter the root password
2. You can stop the MySQL server from the Linux terminal using the following command:
Red Hat-based distros have the service command:
service mysqld stop
Other distros require to call the init script directly:
3. You can start the MySQL server from the Linux terminal same as point2, but with start.
4. You can get the MySQL prompt in the Linux terminal by using point 1.
5. You can log in to the MySQL server from the Linux terminal by the same procedure as mentioned in point 1.
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