Essential Unix Commands

This page serves as a unix manual to help users get to know unix commands and allow for more efficient research in the command line.

Most of the information on this page comes from Dr. Bill Miller III at A. T. Still University.

Here are some of the most important/frequently used commands. These are the basics to using linux machines and working on the command line.

Essential Linux Commands

Command	Option	What it Does	Example
cd		Changes the working directory to the home directory (a folder named your net ID).	cd
	..	Changes the working directory to the folder containing the current working directory.	cd ..
	[directory]	Changes your working directory to the one you specify.	cd my_project
exit		Exits the current working network point. If I am logged into a node on ACME, typing exit will move my working location to the head node on ACME.	exit
ssh [cluster name]		Moves working location to another computer in the network.	ssh acme
rlogin [node name]		Moves to a node in a cluster on the network.	rlogin node01
pwd		Returns the current working directory.	pwd
ls		Lists all the folders and files in the working directory.	ls
cp [file] [location]		Copies file1 and makes a duplicate in the same working directory that is called location OR makes a copy of file1 in the different specified directory called location/.	cp file.com copy.txt OR cp file.com pre_run/
	-r	Same as the previous, but allows the copying of folders (including their contents) too.	cp -r folder1 folder2/
scp [file] [cluster]		Copies files to another computer in the network. The -r option works for secure copy too.	scp file.com acme
mv [item] [location]		Moves a file (or folder if using the -r option) to the specified location. This is used to rename files as well.	mv file.com jobs/ OR mv file.com file2.com
rm [file]		Deletes a file.	rm file.com
	-r	Deletes a folder.	rm -r my_jobs/
mkdir [folder name]		Makes a folder.	mkir my_jobs/
rmdir [folder name]		Deletes an EMPTY folder.	rmdir my_jobs/
less [file name]		Opens a file for viewing only. Once viewing the file,``shift+g`` will take you to the bottom of the document (g alone will take you to the top). Typing ?[text] will search the document for instances of '[text]' above the current cursor location. q quits.	less file.com
vi [file name]		Opens a file for viewing or editing. Files start in viewing mode. While in viewing mode, typing dd will delete the line on which the cursor resides. To enter insert mode, type i. Once in insert mode, you can make changes to the text. To exit insert mode, hit the esc key. To save and quit, type :wq then hit enter (while not in insert mode). To quit without saving, type :q!, then hit enter.	vi file.com
cat [file name]		Prints the contents of a file to the Terminal window.	cat file.com

If you have these commands down, here are a few more (in some more detail) that might be useful as well: