The Terminal

Before we start learning how to use Linux (remember, Linux is based on UNIX. I will use the two terms interchangeably throughout the course), I want to add a couple details about the Linux Terminal. Again, the Terminal is the program that allows the user to interface directly with the computer. Only Linux/UNIX computers have a Terminal program, which is why you all have been given an account on a remote computer.

My Terminal at startup with some customization

On a Mac, you can open a Terminal by going to Finder > Utilities > Terminal. On a Windows computer, again, there is no Terminal, but you can open PowerShell by clicking Start and typing PowerShell in the search bar. In both cases you can perform actions by typing and executing specific commands. As you type, your text will be entered into the prompt. In the image above, the prompt is the line that ends with >>, but note that I have set my prompt to look that way. Yours will probably look different. We will spend some time learning about a variety of commands that allow us to create and manipulate files, perform basic data analysis tasks, access remote computers and more in this class.

When you execute a command commands using the Terminal you may need to include a(n) argument(s); pieces of information that a specific command needs to do its job. Some commands do not require any arguments while others may require 1 or more.

A useful command

In the above example, I am using the scp command to transfer a file from a NASA computer to my local computer (this command is not available on windows computers). We will talk about this command later, but you can see that the first set of characters that come after the prompt must always be a command. Then, any characters that come after a command are arguments, each separated by a space. In this case, there are two arguments.

Note

I want to stress that the first set of characters that come after the prompt must be a command. A common error for users is to try to type a filename or something, and hit enter. Even if the filename that you are typing exists in the location that you are working in on your filesystem, you will still get an error. Another common error is to simply misspell the command that you are trying to enter.