sudo bash setup-battery-hibernate.sh

setup-battery-hibernate.sh

#!/bin/bash

set -e

echo "🔧 Creating 8G swap file at /swapfile..."
sudo fallocate -l 8G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile

echo "💾 Adding swap to /etc/fstab if not present..."
grep -q "/swapfile" /etc/fstab || echo "/swapfile none swap defaults 0 0" | sudo tee -a /etc/fstab

echo "⚙️ Creating battery check script..."
sudo tee /usr/local/bin/battery-hibernate.sh > /dev/null <<'EOF'
#!/bin/bash

LOGFILE="/var/log/battery-hibernate.log"
BATTERY_FILE="/sys/class/power_supply/BAT0/capacity"

if [ ! -f "$BATTERY_FILE" ]; then
  echo "$(date): Battery info file not found. Exiting." >> "$LOGFILE"
  exit 1
fi

BATTERY=$(cat "$BATTERY_FILE")

echo "$(date): Battery at $BATTERY%" >> "$LOGFILE"

if [ "$BATTERY" -le 5 ]; then
  echo "$(date): Critical battery level ($BATTERY%). Hibernating..." >> "$LOGFILE"
  systemctl hibernate
else
  echo "$(date): Battery level ok. No action taken." >> "$LOGFILE"
fi
EOF

sudo chmod +x /usr/local/bin/battery-hibernate.sh

echo "🛠️ Creating systemd service..."
sudo tee /etc/systemd/system/battery-hibernate.service > /dev/null <<EOF
[Unit]
Description=Hibernate system when battery is critical
After=multi-user.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/battery-hibernate.sh
EOF

echo "⏲️ Creating systemd timer..."
sudo tee /etc/systemd/system/battery-hibernate.timer > /dev/null <<EOF
[Unit]
Description=Check battery level every 2 minutes

[Timer]
OnBootSec=1min
OnUnitActiveSec=2min
Unit=battery-hibernate.service

[Install]
WantedBy=timers.target
EOF

echo "🚀 Enabling timer..."
sudo systemctl daemon-reexec
sudo systemctl daemon-reload
sudo systemctl enable --now battery-hibernate.timer

echo "✅ Done. Battery hibernation active at 5%."