Hidden within the confines of the elegant Mac OS X, is a powerful Unix based terminal that allows you to fully utilize your system and its resources. This tutorial is aimed at helping you become familiar with some useful commands that will help you customize your OS, secure your system and entice you to dive deeper into the operating system. All that’s required is Mac OS X, and a little curiosity.
This tutorial will be broken up into four parts. The first part explained how to utilize and explore the terminal , This second part consisted of security related commands  or commands that can be used to secure your system. This third part dealt with the customization of your operating system , and some useful commands you can use to impress your colleagues and friends. Lastly, this tutorial will explore some of the tools utilized to test your Mac and it’s performance. Just to reiterate, all that is required is Mac OS X and a little curiosity.
Part 4 Configuring and Testing Your Mac:
From time to time you may run into performance issues on your Mac. The following command will help you determine if there’s a problem with your CPU. Hopeuflly, once you type the command your system should continue to run without any issues, however if your computer crashes or freezes there’s a good chance your CPU or your RAM need to be replaced.
Enable Command: yes
Disable Command: control Z + yes
Note: Depending on the number of cores your Mac supports you can type additional yes commands to test the performance. For example, if you have a dual core Mac you can type (yes & yes)
Another very useful command that helps you determine which programs are running and how much of your computers resources each program is consuming is the “top “ command which will show running processes.
Enable Command: top
Reversal Command: control + c
Another very useful command that perfectly compliments the “top” command is the “kill” command. The “kill” command in conjunction with a program id (PID), which you can retrieve using the “top” command immediately stops the process associated with it. For example “kill 23978” would forcefully quit my mail application.
kill process ID
Hopefully, your terminal hacking went well and you have a new found appreciation and curiosity for what lies under the Mac OS X hood. The above commands are only a tiny slice of what the terminal can do you for you. I urge you to continue to explore and always ask yourself, how far can I push my Mac?