add Arch support and tidy up

install_prereq.sh

@@ -1,10 +1,36 @@
-#!/bin/bash
+#!/usr/bin/env bash
+set -euo pipefail
 
-set -e
+debianInstall() {
+	sudo apt-get update
+	sudo apt-get install -y git iw dnsmasq hostapd screen curl build-essential python3-pip python3-setuptools python3-wheel python3-dev mosquitto haveged net-tools libssl-dev
+	python3 -m pip install --user --upgrade paho-mqtt tornado git+https://github.com/drbild/sslpsk.git pycryptodomex
+}
 
-sudo apt-get update
-sudo apt-get install -y git iw dnsmasq hostapd screen curl build-essential python3-pip python3-setuptools python3-wheel python3-dev mosquitto haveged net-tools libssl-dev
+archInstall() {
+	sudo pacman -S --needed git iw dnsmasq hostapd screen curl python-pip python-wheel python-pycryptodomex python-paho-mqtt python-tornado mosquitto haveged net-tools openssl
+	python -m pip install --user --upgrade git+https://github.com/drbild/sslpsk.git
+}
 
-sudo -H python3 -m pip install --upgrade paho-mqtt tornado git+https://github.com/drbild/sslpsk.git pycryptodomex
+if [[ -e /etc/os-release ]]; then
+	source /etc/os-release
+else
+	echo "/etc/os-release not found! Assuming debian-based system, but this will likely fail!"
+	ID=debian
+fi
+
+if [[ ${ID} == 'debian' ]] || [[ ${ID_LIKE-} == 'debian' ]]; then
+	debianInstall
+elif [[ ${ID} == 'arch' ]] || [[ ${ID_LIKE-} == 'arch' ]]; then
+	archInstall
+else
+	if [[ -n ${ID_LIKE-} ]]; then
+		printID="${ID}/${ID_LIKE}"
+	else
+		printID="${ID}"
+	fi
+	echo "/etc/os-release found but distribution ${printID} is not explicitly supported. Assuming debian-based system, but this will likely fail!"
+	debianInstall
+fi
 
 echo "Ready to start upgrade"