QR Codes
Make a QR Code image:
qrencode 'https://play.google.com/store/apps/details?id=org.briarproject.briar.android' -o "$FILE".png
Make a QR Coded message in the terminal:
qrencode -t ansi "Hello World"
Read a QR Code image:
zbarimg $FILE
Show wifi QR code (only with Network Manager):
nmcli device wifi show-password