Bash shell script to run a desired action on a HomeMatic CCU

homematic-action.bash

#!/bin/bash

ccuip="192.168.178.XX" # private/LAN (this way, the action can't be executed outside the home network, except if you happen to be connected to it via a VPN) IP address of your HomeMatic CCU
action="<prototypejs><![CDATA[<YOUR ACTION>]]></prototypejs>" # Copy the action request data from browser dev tools

# Fetch session id
sid=$(curl -sD - "http://${ccuip}/pages/index.htm&client=3" | sed -n "s/^.*\(sid.*\)$/\1/p"); # Only if automatic login is activated on your CCU, this request will receive a response with a session id (sid) which can be found by sed # If you run this script too often (multiple times within a short period), the CCU will not respond with new sids due to "too many connections" for a few minutes.
sid="${sid//[$'\t\r\n ']}"; # sanitize: filter out \t,\r,\n,space chars

# Request desired action, e.g. "open door" on a KeyMatic lock
curl "http://${ccuip}/esp/system.htm?${sid}" --data "${action}";

exit