Command Line Cheat Sheet – CLI Commands for Easy Reference

What Is a Command Line Interface?

A command line interface (CLI) is a computer's text interface allowing you to type commands for the computer to run.

Below is an image of the Windows PowerShell terminal application.

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Command line interfaces are sometimes called terminals.

A terminal's command comprises three components: a utility, a flag, and an argument.

Here is the syntax:

utility -flag argument

Note the following:

A utility tells the computer the function you want it to run. Many CLI commands require only a utility.
A flag alters the utility's mode of operation. In other words, we use flags to specify preferences on how computers should run the utility command.
Flags always start with one or two hyphens (-).
Flags are typically written after the utility command and before an argument.
An argument says the exact action the utility command should perform.

Let's now see some of the widely used commands.

Below are the commands for creating, accessing, and deleting directories on your system.

info

Directories are sometimes called folders.

Description	Command
Check the current working directory's path	`pwd`
Change directory from the current working directory to `another-directory`	`cd another-directory`
Change directory from the current working directory to its parent directory	`cd ..` note The whitespace between `cd` and `..` is essential.
Copy `directory1` into `directory2`	`cp -r directory1 directory2` note The duplicated directory will overwrite an existing directory with the same name.
Remove a directory permanently from your system	`rm -r name-of-directory-to-delete`
Remove a directory permanently and forcefully from your system	`rm -rf name-of-directory-to-delete-forcefully`
List out the current directory's content	`ls`
List out the current directory's content using the long listing format	`ls -l`
List out all the current directory's content—including all hidden content	`ls -a`
List out all the current directory's content using the long listing format. Also, include all hidden content	`ls -la`
Make a new directory	`mkdir name-of-new-directory`

Below are the commands for creating, accessing, and deleting your system's files.

Description	Command
Create a new file	`touch name-of-new-file`
Create `test1.md` file	`touch test1.md`
Create `test1.md`, `test2.md`, `test3.md`, and `test4.md` files	`touch test{1..4}.md`
Copy a file into a specific directory	`cp file-to-copy directory-to-copy-file-into` note The duplicated file will overwrite an existing file with the same name.
Display all the content in a specific file	`cat filename`
Display some of the content in a specific file	`less filename` tip Press the 'Enter' key (or the up and down keys) to show more content. Press the Q key to exit the file space.
Display the first ten (10) lines of a specific file	`head filename`
Display the last ten (10) lines of a specific file	`tail filename`
Move a file into a new directory	`mv file-to-move directory-to-move-file-into` note The moved file will overwrite an existing file with the same name.
Remove a file permanently from your system	`rm name-of-file-to-delete`
Remove a file permanently and forcefully from your system	`rm -f name-of-file-to-delete-forcefully`
Rename a file	`mv current-file-name new-file-name`

Below are the commands for downloading and testing network resources.

Description	Command
Download a file	`curl -O url-of-the-file` note The -O flag must be in uppercase.
Test a network host's reachability	`ping domain-name.com`

Below are the commands for displaying your system's information.

Description	Command
Display the current date and time	`date`
Display your CPU's information	`cat /proc/cpuinfo`
Display your memory's information	`cat /proc/meminfo`
Display your system's disks usage information	`df`
Display your current directory's space usage information	`du`
Clear your terminal's content	`clear`