You may need to add a path to a certain program or daemon if you are returned “command not found” line when tou attempt to run it. Go to ~/.bash_profile and open it. You must know where the software you are willing to start is located so that you could type the correct path to it.
Let’s assume you installed MySQL. The daemon for MySQL is located in /etc/init.d directory and it is called mysqld. You certainly can start it by issuing the following command:
/etc/init.d/mysqld start
In case you want to use only mysql without the full path here’s what you need to add into ~/.bash_profile:
export PATH=$[PATH}:/etc/init.d
You will get something similar to the following picture:
