View source for Docs:00.2 Terminal Unix Commands Cheat Sheet

Linux and Mac OS systems have Unix Shells that provide us a command line interface. e.g. Bash Shells or Zsh

Windows uses Power Shell by default, which has a different command language. If you are on Windows you will need a Bash shell installed for the following commands.

Much of working on the command line involves navigating around your system without the use of a Graphical User Interface (GUI). Below we have a representation of a folder (or directory) hierarchy with a plain text .txt file nested inside two folders:
 rootdirectory/ 
    ├─ anotherdirectory/ 
        ├─ aFileName.txt
Which could be written as "/rootdirectory/anotherdirectory/aFileName.txt"

In reality when working on the command line your root folder/directory for your user account on your system will looking something like below (in this case the user is pubdoc), the root folder/directory is denoted by a tilde <code>~</code>
[[File:PubdocUser.png|alt=user name on the command line example|none|thumb]]
=== Terms ===
A few terms we need to be comfortable with before moving forward are:
* '''directory''' : also known as a folder
* '''root directory''' : “highest” directory in the hierarchy. You can also think of it as the start of a particular folder structure, denoted by a tilde <code>~</code> on the command line.
* '''directory path''' : in the example above, there would be a directory called “<code>rootdirectory</code>”, which has a folder called “anotherdirectory” inside of it, the path would be: <code>/rootdirectory/anotherdirectory</code>
* '''file''' : a file, e.g. file.txt or index.html<span id="basic-commands"></span>
=== Basic Commands ===

The following commands will help us get started, but are just the tip of the [https://www.geeksforgeeks.org/linux-commands/?ref=lbp iceberg]

Show the name of the currently logged in user:

<syntaxhighlight lang="shell">whoami</syntaxhighlight>
Show the name of the machine is given on the network:

<syntaxhighlight lang="shell">hostname</syntaxhighlight>
<code>sudo</code> stands for [https://www.geeksforgeeks.org/sudo-command-in-linux-with-examples/ Super User DO]. This command is used to allow you to run commands that only super users are allowed to run, and is often followed by the command you want to run. When you use <code>sudo</code> you will be prompted to enter your super user password to execute the command:

<syntaxhighlight lang="shell"> sudo <command></syntaxhighlight>
If you want to enter into sudo mode to run all commands as a super user, run:

<syntaxhighlight lang="shell"> sudo su</syntaxhighlight>
(this will then prompt you to enter your password and after which you can run commands as a super user)

Print working directory that you are currently in:

<syntaxhighlight lang="shell">pwd</syntaxhighlight>
Change directory to a directory using the “path” to that folder/directory:

<syntaxhighlight lang="shell">cd /directoryname/anotherdirectory</syntaxhighlight>
Change directory to root :

<syntaxhighlight lang="shell">cd </syntaxhighlight>
Change directory to the directory above the one you are currently in:

<syntaxhighlight lang="shell">cd ..</syntaxhighlight>
List current directory contents:

<syntaxhighlight lang="shell">ls</syntaxhighlight>
Make new directory. When working on the command line it is customary for anything that is variable, i.e. in the example below <code>mkdir</code> is our command, and you would then write the name of the folder:

<syntaxhighlight lang="shell">mkdir directoryname</syntaxhighlight>
However, in instructions you might see something like this:

<syntaxhighlight lang="shell">mkdir <directoryname></syntaxhighlight>
Make new file:

<syntaxhighlight lang="shell">touch <example.txt></syntaxhighlight>
A quick way to print contents of a file to your terminal:

<syntaxhighlight lang="shell">cat <example.txt></syntaxhighlight>
Copy a text file called <code>example.txt</code> which is in a sub directory “exampleFolder” to a new location <code>/path/to/folder</code>:

<syntaxhighlight lang="shell">cp exampleFolder/example.txt /path/to/folder</syntaxhighlight>
Remove a file, be careful with removing files!

<syntaxhighlight lang="shell">rm <file.txt></syntaxhighlight>
Remove an empty directory:

<syntaxhighlight lang="shell">rmdir <directoryname></syntaxhighlight>
Remove a directory and all the items inside of it:

<syntaxhighlight lang="shell">rm -r <directoryname></syntaxhighlight>
<span id="command-line-text-editors"></span>
=== Command Line Text Editors ===

===== Nano =====
Edit a file using [https://www.nano-editor.org/ nano] command line text editor:

<syntaxhighlight lang="shell">nano <example.txt></syntaxhighlight>Simple quick start for editing a text file:

* You will see the nano editor open. At the bottom of the window, you will find some shortcuts to use with the Nano editor. The <code>^</code> (caret) means that you must press '''CTRL''' (Windows) or '''control''' (macOS) to use the chosen command. 
* You should be able to edit and enter text in your file. 
* Press '''CTRL + O''' to save the changes made in the file and continue editing. 
* To exit from the editor, press '''CTRL + X'''. If there are changes, it will ask you whether to save them or not. Input '''Y''' for '''Yes''', or '''N''' for '''No''', then press '''Enter'''. If there are no changes, you will exit the editor right away.

[https://itsfoss.com/nano-editor-guide/ getting started with nano], dive deeper into [https://www.nano-editor.org/ nano]

===== Vim =====

Edit a file using [https://vimdoc.sourceforge.net/htmldoc/usr_01.html vim] command line text editor:

<syntaxhighlight lang="shell">vim <example.txt></syntaxhighlight>Simple quick start for editing a text file:

* Press <code>i</code> to insert, then you can make changes to your file. 
* Once you are finished changing your file press escape <code>esc</code> to exit out of insert mode. 
* Then you should type <code>:wq</code> and hit enter to write and quit (save your file and quit). 
* The command to then exit Vim is <code>:q</code>

vim is less beginner friendly, dive deeper into [https://vimdoc.sourceforge.net/htmldoc/usr_01.html vim]
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