Get system info (e.g. IP): ifconfig
Get network info: iwconfig
Get hostname: hostname
Get hostname IP: hostname -I
Check for all connected USB devices: lsusb
Configure Raspberry Pi: sudo raspi-config
Reboot system: sudo reboot
Shutdown: sudo shutdown -h now
Update system & packages: sudo apt-get update & sudo apt-get upgrade
Uninstall package (will remove about everything regarding the package packagename,
but not the dependencies installed with it on installation): sudo apt-get purge packagename
Uninstall orphaned packaged dependencies(will also attempt to remove other packages
which were required by packagename on but are not required by
any remaining packages): sudo aptitude purge packagename
Remove orphaned packages: sudo apt-get autoremove
Check ALSA modules cat /proc/asound/modules
View Audio Hardware cat /proc/asound/cards
View information on selected card (use Audio Hardware query to get card no) amixer -c <card index no>
View Recording devices arecord -l
View Playback devices aplay -l