MIT6.828

In the old time, computing business is constantly searching for ways to do a better job for developing computer applications.

Since computer applications scale is growing at an amazing rate.People at that time need a much more helpful environment to

advence their job.

That's maybe the reason why people had build the Operating System.

Unix System is made up sort of three layers. The Central part is the kernel that controls the resources of the machine.

The part which wrapped around the central part is something called the shell which is the interface between most users and the kernel.

And the outermost layer is which called UTILITIES. It contain sort of useful programs.

The notion of pipeline is the fundamental contribution in Unix. It provided a feature that can stick a bunch of programs together.

The data simply flows from the one on the left to the one on the right and the system itself looks after all the connections and all of the synchronization

making sure that the data goes from the one into another.

input output redirection.

The courses was run under *nix system. To aviod a lots of installation works and tends to not take up valuable system resources in my f**king mbp.

Aliyun is not a bad choice and 9.5 yuan(student disconunt) a month is also very affordable.