#!/bin/bash

# Create file wlan.devs which is a listing of all wireless devices currently attached to my router
# Added to my ~Cow PHLOG on 14 Dec 19

# The output of $ curl is unique to my router make/model.
# Using a different router, $tablestart and $tableend will be different

# These strings appear in the router's landing page just before and after the data I want to capture
tablestart=');setWirelessTable('
tableend=');setWDSTable();setDHCPTable('

# Download a copy of my router's landing page and load it into the variable $devs
curl 192.168.1.1 > wlan.temp
devs=$(<wlan.temp)

# Strip out the stuff before and after the needed table
devs=${devs#*$tablestart}
devs=${devs%$tableend*}

# pretty up the output by listing each connected device on a seperate line
echo "$devs" > wlan.temp
sed -i 's/\, //g' wlan.temp
echo "$(tr ',' '\n' <wlan.temp | paste --serial --delimiters=',,,,,,,,,\n')" > wlan.devs
rm wlan.temp

# Display results
cat wlan.devs

# The contents of wlan.devs (in my case) looks like this:
# 'xx:xx:xx:xx:A9:84','ath0','0:16:09','39M','6M','LEGACY','-56','-93','37','880'
# 'xx:xx:xx:xx:79:73','ath0','0:35:12','58M','6M','LEGACY','-56','-93','37','880'
# 'xx:xx:xx:xx:A5:64','ath0','5 days 6:22:38','54M','2M','LEGACY','-53','-93','40','940'
# I know which device is which based on the MAC address at the start of each line
# If this program is put into a loop (bad form) or called every minute with a cron job,
# we can detect when devices arrive or depart the WiFi's zone and can act on that info
# as needed (eg logging devices or turning on the coffee pot, etc)