Command Line Navigation

This badge is to learn how to navigate using the command line (CLI).

Commands

Commands used when navigating in the CLI:

• cd
• ls
• mkdir
• pwd

Concepts

Navigation requires an understanding of the above commands and of file system paths, both relative and absolute.

Absolute power corrupts absolutely

Absolute paths are the full name to a file or directory starting from root.

If I want to navigate to a folder in my Documents folder (on a Mac), the absolute path would look something like:

$ cd /Users/Amanda/Documents/Thesis/

It’s all relative

Relative paths are partial path names relative to where you are in the directory structure.

If I am in /Users/Amanda, then the way to get to my Thesis folder using the relative path would look something like:

$ cd Documents/Thesis

If I am in my Thesis folder and I want to move to a different folder within my Documents directory, I would do something like:

$ cd ../IF

The double dot notation is shorthand for “go up a directory,” which is this case is Documents. From there, I can then go down into my IF directory (and play some text adventure games).

Here is a more complicated example: from my IF directory, I could get to a folder of pictures in my Pictures directory (absolute path: /Users/Amanda/Pictures/atlanta) by typing:

$ cd ../../Pictures/atlanta/

The first .. takes me up to Documents, the second .. takes me up to my user directory (Amanda) and from there I can go down into Pictures and then into atlanta.

Do

Open a command line window. Explore your file system in the CLI using the following commands and using absolute and relative path names:

• ls
• pwd
• cd

ls means “list” and it will show you the list of files in the directory you are in. Try using some optional arguments such as -a, -p, or -l. What do they show you that just running ls without arguments doesn’t?

pwd means “print working directory,” which is fairly self explainitory. Try typing it in different directories. What does it return?

cd means “change directory,” which is also fairly self explainitory. Try typing in cd by itself. Where does it bring you? Try navigating to a directory within your files system and list the files in that directory. Use absolute and relative paths to visit several different directories on your file system.

Done

Here’s an example of what your CLI screen might look like after completing the above work:

amanda-nyrens-macbook-pro:~ Amanda$ pwd
/Users/Amanda
amanda-nyrens-macbook-pro:~ Amanda$ ls
Calibre Library     Documents       Icon?           Movies          Pictures        Sites           VirtualBox VMs
Desktop             Downloads       Library         Music           Public          Speelies        mydir
amanda-nyrens-macbook-pro:~ Amanda$ cd Desktop/
amanda-nyrens-macbook-pro:Desktop Amanda$ ls
command.txt git-amanda      pystar          python
amanda-nyrens-macbook-pro:Desktop Amanda$ ls -l
total 424
-rw-rw-rw-   1 Amanda  staff  213063 Jul 27  1999 command.txt
drwxr-xr-x   6 Amanda  staff     204 Mar 22 16:18 git-amanda
drwxr-xr-x   7 Amanda  staff     238 Apr  9 09:31 pystar
drwxr-xr-x  33 Amanda  staff    1122 Apr  9 09:23 python
amanda-nyrens-macbook-pro:Desktop Amanda$ cd git-amanda/pystar_amanda/
amanda-nyrens-macbook-pro:pystar_amanda Amanda$ ls -a
.           ..              .DS_Store       .git            README.rst      docs            utils           web
amanda-nyrens-macbook-pro:pystar_amanda Amanda$ pwd
/Users/Amanda/Desktop/git-amanda/pystar_amanda
amanda-nyrens-macbook-pro:pystar_amanda Amanda$ cd ../../../Documents/Thesis/
amanda-nyrens-macbook-pro:Thesis Amanda$ ls -lrt
total 86920
-rwxrwxrwx@  1 Amanda  staff     24576 Oct  4  2005 thesis proposal.doc
-rw-r--r--@  1 Amanda  staff  12562780 Feb 15  2006 ES2e-CH18.pdf
-rw-rw----   1 Amanda  staff      4197 Mar  8  2006 thesis references-Converted.txt
-rw-r--r--@  1 Amanda  staff   3475730 Mar  9  2006 chester_2003.pdf
-rw-r--r--@  1 Amanda  staff    908091 Mar  9  2006 evaluating sand and clay models.pdf
-rw-r--r--@  1 Amanda  staff     34304 Mar 19  2006 thesis budget.xls
-rw-r--r--@  1 Amanda  staff         0 Mar 24  2006 Icon?
-rw-r--r--@  1 Amanda  staff     37376 Mar 29  2006 Manuscript preparation WORD.doc
-rw-r--r--@  1 Amanda  staff     31744 Mar 29  2006 Remaining Important Dates for Departmental Honors Students 2005-06.doc
-rw-r--r--@  1 Amanda  staff   3064448 Apr  9  2006 storti salvini mcclay.pdf
-rwxrwxrwx@  1 Amanda  staff     39424 Apr 13  2006 thrust analysis.xls
-rw-r--r--@  1 Amanda  staff   9557504 Apr 30  2006 Thesis.doc
drwxr-xr-x  38 Amanda  staff      1292 Apr 30  2006 Images
-rw-r--r--@  1 Amanda  staff  14669824 May  7  2006 thesis.ppt
amanda-nyrens-macbook-pro:Thesis Amanda$ pwd
/Users/Amanda/Documents/Thesis
amanda-nyrens-macbook-pro:Thesis Amanda$