Working with the command line

You will likely be using the command line a lot when working with Raspberry Pi’s. Below I provide a concise list of the essentials. If you are not already a bit familiar with the command line, I recommend the free ebook from the Raspberry Pi Foundation.

Terminal control
File and directory commands
Networking and system commands
Raspberry Pi specific commands
Sudo
Installing software using apt

Terminal control

Hold option (alt) and click a position in the current line to move your cursor to that position.
Pressing the UP key will print the last command entered into the command prompt. This is a quick and easy way to repeat or correct previous commands.
Show the history of all entered commands: history
Clear the current window, useful if your previous commands are cluttering things up.: ctrl + l or clear
Stop the process currently running: ctrl + c
While writing in terminal, jump to left and right on the same line: ctrl + a and ctrl + e.
To let something run in the background, even when you close a session you can use screen. To start a new screen screen -s <name> and to later resume it screen -r <name> If you forgot the name of your screen just type screen -r to show the list of screens
To exit the terminal (or screen): exit

File and directory commands

Get the path of the current directory: pwd
Go to directory/go to home directory: cd sample-dirname / cd ~
Go to previous directory: cd -
Make a directory: mkdir sample-dirname
Remove an empty directory: rmdir sample-dirname
Remove a directory and all of its contents: rm -rf sample-dirname/
Create a symlink: ln -s source-dirname destination-dirname
List the contents of the directory: ls
Show the entire lower file tree: tree
Show details of multiple files: file filename1 filename2
Create a new, empty file (e.g. named example.txt) in the current directory: touch sample-filename.txt
Create a file/display the contents of a file: nano sample-filename.txt
To save and exit a file (when editing with nano): ctrl+x, y, Enter
Display the contents of a file: cat sample-filename.txt
Remove a file: rm sample-filename.txt
Move/rename a file: mv current-filename.txt new-filename.txt
Copy file or directory: cp examplefile.txt /home/pi/office/
Copy file from server to local via SSH: scp pi@192.168.0.0:/path/to/file.png ~/Desktop/
Copy file from local to server via SSH: scp ~/Desktop/file.png pi@192.168.0.0:/path/to/folder

Networking and system commands

Check the status of the network connection you are using: ifconfig
Print a list of the currently available wireless networks: iwlist wlan0 scan
Test connectivity between two devices connected on a network or with the internet: ping 10.0.0.32 and ping http://google.com.
Download a file (e.g. example.txt) from the web and saves it to the current directory: wget http://www.website.com/example.txt
Connect to a device using SSH and the device name: ssh pi@rasperrypi.local
Connect to a device using SSH and the IP-addres of the device: ssh pi@192.168.64.xxx
Find all available devices on the network: arp -a
Get the hostname: hostname
Get the hostname IP: hostname -I
List USB hardware connected to your Raspberry Pi: lsusb
Check free space on your Raspberry Pi: df -h
Show the current date and time: date

Raspberry Pi specific commands

Synchronize the list of packages on your system to the list in the repositories: apt-get update
Upgrade all of the software packages you have installed: apt-get upgrade
Following from these, update raspbian to latest version: sudo apt-get update && sudo apt-get upgrade
Open the configuration settings menu: raspi-config
To shutdown: sudo halt or shutdown -h now
To reboot: sudo reboot
Take an image with the camera module: raspistill -0 image.jpg
Stream the camera: raspistill -t 0 -k (to exit: ctrl+x)
Record a 10s video with the camera module: raspivid -o video.h264 -t 10000

Sudo

There are two user “modes” you can work with on the command line. The standard one is a user with basic access privileges. The other is a mode with administrator access privileges (AKA super user, or root). Some tasks can’t be performed with basic privileges and the super user must be used. To do so, the prefix sudo needs to be added to the command.

Installing software using apt

apt is a package manager included with the Raspberry Pi OS that makes it very easy to install and manage new software packages on your Raspberry Pi. Note that a super user (see above) is needed to install or remove packages.

To install a new package: sudo apt install <package-name>
To update list of software packages available on your system: sudo apt update
To remove and uninstall a package: sudo apt remove <package-name>
List all packages on your system: dpkg -l