When you first start using the CLI, you will spend most of your time navigating the file system, looking for things. In this post I’ll give you some tips that should make this process more enjoyable.

When you first open the terminal program you should automatically be in your home directory. Your home directory is where all your files live.

You can verify this by issuing the pwd command. You should see something that looks like this: /home/gabe or /Users/gabe if you are on a Mac. If that’s not what you see, there are a few ways to get there.

You can use the cd command and specify the full path to your home directory like this:

$> cd /home/gabe

Instead of specifying the full path to your home directory, you can use the special shortcut ~/. The shell automatically expands that to the full path of your home directory.

$> cd ~/

Another shortcut for getting back to your home directory is just calling cd without any arguments:

$> cd

If you ever find yourself lost, and don’t know how to get back to your files, any of those options will do the trick.

While navigating around there are a few special directories that exist in every directory. The “.” (dot) and “..” (dot dot) directories always refer to the current directory and the directory one level up the tree, respectively.

For example, if you consider this directory tree:

/
|-- home
    |-- gabe
	    |-- Documents

And you then cd into the Documents directory cd /home/gabe/Documents and issue the ls command you would see something like this:

20120409-endo.pdf
20120601-tres.pdf
Bologna-Hotel-Res.ps
Bologna-Hotel-Reservation.pdf
Brochure-English-web.pdf
CAD
DailyBook

In order to see the “special” directories as well, I need to pass the -a flag to the ls command, like so: ls -a. Then I will see something more like this:

.
..
.login.conf.swp
.stfolder
20120409-endo.pdf
20120601-tres.pdf
Bologna-Hotel-Res.ps
Bologna-Hotel-Reservation.pdf
Brochure-English-web.pdf
CAD
DailyBook

You’ll notices the directory listings look almost the same, except for the first few entries. When I pass the -a flag to the ls command, I’m asking it to “Include directory entries whose names begin with a dot ('.').”

File names that start with a ‘.’ are usually called “hidden files” since they don’t show up when you just run the bare ls command. They also won’t show up in your GUI (graphical user interface) when you are browsing around unless you have specifically told your system to show hidden files. The two hidden files that will appear time and time again are “.” and “..”.

“..” can be used to go up a level in the directory tree. Given I’m in the directory /home/gabe/Documents and I want to go back up to /home/gabe I can just type: cd .. and I will be moved up one level in my directory structure to /home/gabe. I can keep doing this all the way back to the / (root) directory.

$> pwd 
/home/gabe/Documents
$> cd ..
$> pwd
/home/gabe
$> cd ..
$> pwd
/home
$> cd ..
$> pwd
/

One last quick tip for today, if you’ve just changed into a directory but want to go back to where you just came from, you can type cd - (cd dash). This will jump you back and forth between the directory you are currently in, and the directory you were previously in. For example:

$> cd /tmp
$> pwd
/tmp
$> cd -
$> pwd
/home/gabe
$> cd -
$> pwd
/tmp
$> cd - 
$> pwd
/home/gabe

That’s it for this time. If you have any questions, feedback, or suggestions for topics you’d like to see covered, just drop me an email: gabe@cotcli.com

New Terms

. - A single dot or period, means the current working directory
.. - Two dots, means the directory one level above the current working directory
~/ - Tilde slash is a shortcut for your home directory, where all your documents live
hidden file - A file that begins with a single dot, for example: .hiddenfile that won’t show up when you run the ls command, unless you also specify the -a flag.

Getting Around

cd, cd .., cd -, and more.

New Terms