Keep macOS awake while Cisco VPN is connected

keep-awake-on-vpn.sh

#!/bin/bash
# Keep macOS awake while Cisco VPN is connected.
# Uses caffeinate to prevent sleep when a utun interface (VPN tunnel) is active.
#
# Usage:
#   ./keep-awake-on-vpn.sh        # run in foreground
#   ./keep-awake-on-vpn.sh &      # run in background
#
# Stop: kill the script (or Ctrl+C if in foreground)

CHECK_INTERVAL=30  # seconds between checks

CAFFEINATE_PID=""

is_vpn_connected() {
    # Cisco AnyConnect/Secure Client creates utun interfaces when connected.
    # Also check for the Cisco process as a secondary signal.
    if ifconfig | grep -q "^utun"; then
        # Verify there's actual traffic capability (interface has an IP)
        if ifconfig | grep -A5 "^utun" | grep -q "inet "; then
            return 0
        fi
    fi
    return 1
}

start_caffeinate() {
    if [ -z "$CAFFEINATE_PID" ]; then
        # -d: prevent display sleep
        # -i: prevent idle sleep
        # -s: prevent system sleep (on AC power)
        caffeinate -dis &
        CAFFEINATE_PID=$!
        echo "$(date): VPN connected — keeping Mac awake (caffeinate PID: $CAFFEINATE_PID)"
    fi
}

stop_caffeinate() {
    if [ -n "$CAFFEINATE_PID" ]; then
        kill "$CAFFEINATE_PID" 2>/dev/null
        wait "$CAFFEINATE_PID" 2>/dev/null
        CAFFEINATE_PID=""
        echo "$(date): VPN disconnected — allowing sleep"
    fi
}

cleanup() {
    stop_caffeinate
    echo "$(date): Script stopped"
    exit 0
}

trap cleanup EXIT INT TERM

echo "$(date): Monitoring Cisco VPN connection (checking every ${CHECK_INTERVAL}s)..."

while true; do
    if is_vpn_connected; then
        start_caffeinate
    else
        stop_caffeinate
    fi
    sleep "$CHECK_INTERVAL"
done