Linux Basics #

You are about to see a lot of potentially unfamiliar commands below. Don’t worry about memorizing all of these right away .

The only way of getting familiar with these commands is by using them. So if that means you need to look up a Linux cheat-sheet every time or you print out a list of these on your desk, that’s perfectly normal.

Some of these commands have strange, un-intuitive names which still cause the most experienced Linux users to forget or confuse them.

Syntax Used #

When a command is shown in a code block, it may be followed by optional or required arguments:

• Optional arguments will be enclosed with square brackets: [optional].

• Required arguments will be enclosed with angle brackets: <required>.

When you actually enter these commands at a prompt, do not include any brackets.

File System Commands #

pwd - Print the current working directory.

pwd

ls - List all of the files in the current directory.

ls [-a Show hidden files] [-l Show as list with details]

rm - Remove (delete) on or more files

rm <File 1> [File 2] [File 3] ...

Once a file is removed, it typically cannot be recovered!

If you accidentally remove a file on a lab machine, the CS department occasionally runs backups of everyone’s files and you may be able to recover it by contacting the department.

cd - Change directory

cd <Directory name>

Use cd .. to go up to the parent directory.

cp - Copy a file

Usage:

cp <Source file> <Destination>

mkdir - Create a new directory

mkdir <New directory name>

rmdir - Delete an empty directory

rmdir <Directory Name>

Other Commands #

cat - Output the contents of a file to the screen

cat <File name>

more - Output one screenful of a file. Press Enter to scroll down. Press q to quit.

more <File name>

nano - Open the nano text editor. Use Control+X to exit (you may be prompted to save, type y or n).

nano [File name]

vim - Open the vim text editor. To quit, first press Escape then type :q! to quit without saving, or :wq to save and quit.

vim [File name]

How to Learn More About a Command #

Most commands have many arguments you can specify to them. If you want to see all the possible arguments you can provide to a command and what they do, you can check the “man”, or manual, page for a specific command.

To do so:

man <command name>

For example, to learn more about the ls command, you could type:

man ls

If you are still unsure about a command, the next step is to look online for more documentation and examples.