Terminal – Part 1 – Directories & Content

The Terminal also known as Command Line Interface (CLI) can be a scary place if you dont know what you are doing. Once you get used to it, it starts to be logical and will become second nature.

Below is the LXTerminal from the Raspbian Distribution

terminal

When you first start the Terminal you are presented with the following:

pi@rpi-two ~ $ 

The first part pi is your username you are logged on with. The second part rpi-two (in my case) is the name of the computer

First Steps

To ease you in gently, lets find something about ourselves

who am i

As the command suggests, it queries what user you are logged in as:

pi@rpi-two ~ $ who am i
pi       pts/2        2014-09-13 21:44 (192.168.1.8)

This displays various information such as Username pi, Connection Type pts/2 (0 is locally logged on, I am using ssh to connect remotely), Date/Time 2014-09-13 21:44 and IP Address (192.168.1.8).

Directory Navigation

Whether you call them Folders of Directories they are the same thing:- basically a box that contains stuff. So lets figure how to navigate around.

Where Am I ?

To find out where you are, type the following:

pwd

pwd stands for Print Working Directory. It will tell you which directory you are currently in

pi@rpi-two ~ $ pwd
/home/pi

By default when you log in, you log into the root of your user. In this case /home/pi

Listing Directories

Great, now we know where we are, but is there any content inside of this directory ? To do this we will use theList Directory Contents command ls. In the Terminal type the following:

ls

This will list you the contents of your current directory

pi@rpi-two ~ $ ls
Desktop    Downloads  npm-debug.log  python        Scratch
Documents  indiecity  ocr_pi.png     python_games  wwwroot

(I have a couple of extra directories, so dont worry if yours doesnt match exactly)

The ls command has some options which changes the way the content is displayed:

pi@rpi-two ~ $ ls -l
total 44
drwxr-xr-x 2 pi pi 4096 Sep  3 22:09 Desktop
drwxr-xr-x 3 pi pi 4096 Aug  1 19:48 Documents
drwx------ 2 pi pi 4096 Sep  6 20:01 Downloads
drwxr-xr-x 3 pi pi 4096 Aug  9 19:50 indiecity
-rw-r--r-- 1 pi pi 2153 Jun 29 09:41 npm-debug.log
-rw-r--r-- 1 pi pi 5781 Feb  3  2013 ocr_pi.png
drwxr-xr-x 2 pi pi 4096 Aug  9 08:41 python
drwxrwxr-x 2 pi pi 4096 Jan  1  1970 python_games
drwxr-xr-x 2 pi pi 4096 Aug  1 19:48 Scratch
drwxr-xr-x 3 pi pi 4096 Jun 28 15:41 wwwroot

The -l switch, displays the content in a long list. Don’t worry about the information displayed, we will discuss that later

Using the -t switch, puts them in Date order, latest Date at the top

pi@rpi-two ~ $ ls -t
Downloads  indiecity  Documents  npm-debug.log  ocr_pi.png
Desktop    python     Scratch    wwwroot        python_games

So, if we combine both l & t, we get a long list in date order !

pi@rpi-two ~ $ ls -lt
total 44
drwx------ 2 pi pi 4096 Sep  6 20:01 Downloads
drwxr-xr-x 2 pi pi 4096 Sep  3 22:09 Desktop
drwxr-xr-x 3 pi pi 4096 Aug  9 19:50 indiecity
drwxr-xr-x 2 pi pi 4096 Aug  9 08:41 python
drwxr-xr-x 3 pi pi 4096 Aug  1 19:48 Documents
drwxr-xr-x 2 pi pi 4096 Aug  1 19:48 Scratch
-rw-r--r-- 1 pi pi 2153 Jun 29 09:41 npm-debug.log
drwxr-xr-x 3 pi pi 4096 Jun 28 15:41 wwwroot
-rw-r--r-- 1 pi pi 5781 Feb  3  2013 ocr_pi.png
drwxrwxr-x 2 pi pi 4096 Jan  1  1970 python_games

There are many more options, if you want to have a look, here are some websites:

LostAngles

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