Scriptlet for creating QR codes that let people join a WiFi network just by scanning the code.

qrenc-wifi

#! /usr/bin/env ruby

# Take a network SSID as an argument, and prompt for the corresponding
# password. Generate a WiFi-network credential set suitable for QR
# encoding as defined in:
#
# https://github.com/zxing/zxing/wiki/Barcode-Contents#wi-fi-network-config-android-ios-11
#
# then generate that QR code and save it to `<SSID>-QR.png`.
#
# It does all of this using Duncan Robertson's rqrcode Gem:
#
# https://github.com/whomwah/rqrcode

require 'rqrcode'
require 'io/console'

network = ARGV.first

if network
  passwd = STDIN.getpass("Password: ")

  wifi_info = "WIFI:S:#{network};T:WPA;P:#{passwd};;"
  filename = "#{network}-QR.png"

  RQRCode::QRCode.new(wifi_info).
    as_png(size: 360, file: filename)
else
  puts <<~EOM
    Generate the PNG of a QR code for WiFi-network access. Pass it the
    SSID (WiFi network name); it will prompt for the password and
    generate `<SSID>-QR.png`.
  EOM
end