Setting up a UNIX terminal

You will be doing a lot of work in the UNIX terminal - this is a command-line interface. If you're not familiar with this, you will need to get used to using it.

Installing the terminal

Linux computers have the terminal built in - there's nothing to install. (Although you can, if you want to, install any of several different flavours. The default one might be Gnome Terminal. If you're using Linux you almost certainly know how to find this already so we won't go into more detail here.

Mac OS X computers also already have a terminal built-in. You can find it in Applications/Utilities/Terminal. Drag into your dock to make it easily available.

Windows computers don't natively have a UNIX environment, but luckily you can install one without difficulty. This is called the 'Windows Subsystem for Linux' and I've given instructions on this at the bottom of this page. Once you have this installed, come back and test out your terminal.

Testing the terminal

Whichever method you use, you should now be able to start your terminal, will look something like this:

!img

Now let's check it is working - here are a few practice commands to try.

1. To find out where we are in the filesystem use the pwd ('present working directory') command:

$ pwd

Note. Don't type the dollar sign - that's there to indicate the command prompt. Type pwd command and press <enter> to run it.

You should see something like /home/geoff (if geoff is your username.)

2. Printing some output. A simple way to print stuff is the 'echo' command (which echoes what you've just written):

$ echo "Hello, this is a message"

3. Creating a file. One way is to 'echo' some text and redirect the output to a file. LIke this:

$ echo "Hello, this is just a test file" > test.txt

4. Listing files. To see what's in your current directory, try the ls command:

$ ls

(You should see test.txt among any other files that are in there.) Or to see the same thing but with lots of detail about when the files were created / accessed / modified and so on, try ls -l:

$ ls -l

4. Seeing file contents. A simple way is to use cat ('concatenate') which just prints out the contents:

$ cat test.txt

A more interactive way is to use less - first let's put some more lines in:

echo "This is a second line" >> test.txt
echo "And this is a third line" >> test.txt

Note. The >> above says 'add this stuff to the end'.

Now use less to view it:

$ less test.txt

(Press q to quit less). less is very useful when the file gets larger than the size of your window, as it lets you scroll around.

5. Moving around. Of course you don't have to stay in this directory - use cd (change directory) to move around. Since you are in /home/users/, go up one level to find out what other users are on your system:

$ cd ..
$ ls

Note. .. means "up one level to the parent directory".

Or up another level to see what's in the filesystem root:

$ cd ..
$ ls

At this point you should see a bunch of stuff - including home, usr, etc and other folders of that sort. These are all part of the standard UNIX filesystem.

Installing the Windows Subsystem for Linux

To install the UNIX terminal on Windows 10 or above, the best bet is the Windows Subsystem for Linux. It comes with Windows 10 and effectively installs a copy of Ubuntu linux that interoperates well with your Windows computer. You can see full installation instructions here, but here's a brief guide:

• Start a Windows command prompt in "run as administrator" mode. To do this, type 'command' into the search box next to the Start menu. Find the 'Command Prompt' app in the results. Don't click it - instead, right-click on it and select 'run as administrator'. You will be asked to allow the app to make changes to your device - click yes. (If you don't have administrator priviledges, you'll have to ask your administrator to follow these instructions for you.

• Now in the command prompt, type wsl --install and press <enter>.

This will take a minute or two - during this time you'll see various messages about Windows downloading and installing various components.

• Reboot your computer.

Once you log back in, the installation will continue - a window will open saying 'Installing: Ubuntu' (i.e. it is installing a recent version of Ubuntu Linux.)

Note. When I tested this, this window never disappeared, but the 'Ubuntu' app was nevertheless installed. So give this a few minutes and then carry on.

• Once installation is complete, you should have a new Ubuntu app in your start menu. The first time you click it, it will ask you to choose a new username and password. I suggest to use the same username as you have on your computer, but in any case don't forget these!

Interacting with the filesystem.

On Mac OS and on Linux, the filesystem in the terminal is the same one the computer uses - you can see the same files in the Finder / file explorer. For example your home directory (where you start) is the same place as the main one on your system.

If you are Windows it's slightly different however:

• The UNIX shell home directory is a new one - not the same as C:/Users/>username<.
• Instead the C: drive appears in the UNIX shell as /mnt/c and similarly for other drives.
• The UNIX filesystem is in fact still accessible through Windows Explorer, but at a slightly odd path (see below).

For Windows users only: to explore this let's cd (change directory) to the C drive and see what's in there:

$ cd /mnt/c
$ ls

You should see a bunch of files and folders - including Users, Program Files, and so on.

You probably can't create files in this folder due to permissions - so let's go to your Desktop instead. Try that now:

$ cd Users/>my user name</Desktop

Note. This is your Windows username - hopefully the same as the username you chose above.

Now you can create a file:

echo "Hello, this is a UNIX text file" > test.txt

If you look on your Desktop you will now have a new file called test.txt with this fascinating message in it!

(Going the other way - seeing the UNIX filesystem from Windows - seems more difficult.)

Next steps

Congratulations! You are now set up with a UNIX terminal.