automatically change the power profile depending on the connection and

bat percentage

bin/power-monitor.sh

@@ -0,0 +1,87 @@
+#!/usr/bin/env bash
+# ~~stolen~~ inspired by https://github.com/linuxmobile/kaku/blob/niri/home/services/system/power-monitor.nix
+
+set -euo pipefail
+
+STARTUP_WAIT=0
+
+log() {
+  echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" >&2
+}
+
+get_battery_path() {
+  local bat_path
+  bat_path=$(echo /sys/class/power_supply/BAT*)
+  if [[ ! -d "$bat_path" ]]; then
+    log "No battery found"
+    exit 1
+  fi
+  echo "$bat_path"
+}
+
+readonly BAT="$(get_battery_path)"
+readonly BAT_STATUS="$BAT/status"
+readonly BAT_CAP="$BAT/capacity"
+readonly LOW_BAT_PERCENT=30
+
+readonly AC_PROFILE="performance"
+readonly BAT_PROFILE="balanced"
+readonly LOW_BAT_PROFILE="power-saver"
+
+for file in "$BAT_STATUS" "$BAT_CAP"; do
+  if [[ ! -f "$file" ]]; then
+    log "Required file not found: $file"
+    exit 1
+  fi
+done
+
+if ! command -v powerprofilesctl >/dev/null 2>&1; then
+  log "powerprofilesctl not found"
+  exit 1
+fi
+
+if [[ -n "''${STARTUP_WAIT:-}" ]]; then
+  sleep "$STARTUP_WAIT"
+fi
+
+get_power_profile() {
+  local status capacity
+  status=$(cat "$BAT_STATUS")
+  capacity=$(cat "$BAT_CAP")
+
+  if [[ "$status" == "Discharging" ]]; then
+    if [[ "$capacity" -gt $LOW_BAT_PERCENT ]]; then
+      echo "$BAT_PROFILE"
+    else
+      echo "$LOW_BAT_PROFILE"
+    fi
+  else
+    echo "$AC_PROFILE"
+  fi
+}
+
+apply_profile() {
+  local profile=$1
+  log "Setting power profile to $profile"
+  if ! powerprofilesctl set "$profile"; then
+    log "Failed to set power profile"
+    return 1
+  fi
+}
+
+log "Starting power monitor"
+prev_profile=""
+
+while true; do
+  current_profile=$(get_power_profile)
+
+  if [[ "$prev_profile" != "$current_profile" ]]; then
+    apply_profile "$current_profile"
+    prev_profile=$current_profile
+  fi
+
+  if ! inotifywait -qq "$BAT_STATUS" "$BAT_CAP"; then
+    log "inotifywait failed, sleeping for 5 seconds before retry"
+    sleep 5
+  fi
+done