Monitor signal strength (RSSI) of the active Wi-Fi network on macOS

rssi.sh

#!/bin/bash

# SPDX-FileCopyrightText: 2019 Kirill Elagin <https://kir.elagin.me/>
# SPDX-License-Identifier: MPL-2.0

###
#
# Monitor signal strength (RSSI) of the active Wi-Fi network on macOS.
#
# Usage:
#   rssi.sh
#
# https://gist.github.com/kirelagin/6a575ad6dcb5be8540dc70d8992f926a
###


airport() { /System/Library/PrivateFrameworks/Apple80211.framework/Resources/airport "$@"; }
plistb() { /usr/libexec/PlistBuddy "$@"; }

tmpf=$(mktemp -t rssi.sh)  # PlistBuddy can't read from stdin :/
tput civis  # hide the cursor
trap 'tput cnorm; rm -f "$tmpf"; trap - INT; kill -s INT "$$"' INT

while true; do
  airport -xI > "$tmpf"
  sig=$(plistb -c 'Print :RSSI_CTL_AGR' "$tmpf"); printf "%s\r" "$sig"
  sleep 1
done