auto-shutdown-for-server-with-bash

gistfile1.txt

# update history after every command
cat << 'EOF' >> ~/.bashrc
# If PROMPT_COMMAND already has commands
if [[ ! -z "$PROMPT_COMMAND" ]]; then
    PROMPT_COMMAND="$PROMPT_COMMAND; history -a"
else
    PROMPT_COMMAND="history -a"
fi
EOF

mkdir ~/bin 

# Write shutdown Bash script to a file
SHUTDOWN_SCRIPT_NAME=${HOME}/bin/idle_shutdown_script.sh
cat <<EOF > ${SHUTDOWN_SCRIPT_NAME}
#!/bin/bash

# Set the idle time limit (30 minutes in seconds)
# IDLE_LIMIT=1800
IDLE_LIMIT=600

# Get the current time in seconds since the epoch
current_time=\$(date +%s)

# Function to get the last modification time of a file in seconds
get_modification_time() {
  local file_path="\$1"
  # Get the last modification time in seconds since the epoch
  stat -c %Y "\$file_path"
}

# List of home directories (assuming /home for user directories)
cd /home
home_dirs=\$(ls)

# Assume all sessions are idle initially
all_idle=true

# Loop through home directories and check the last modification time of .bash_history
for home_dir in \$home_dirs; do
  history_file="\$home_dir/.bash_history"
  if [[ -f \$history_file ]]; then
    last_modification=\$(get_modification_time "\$history_file")

    # Calculate idle time
    idle_time=\$((current_time - last_modification))

    if ((idle_time < IDLE_LIMIT)); then
      all_idle=false  # If any session is active within 30 minutes, set to false
    fi
  else
    all_idle=false  # If there's no .bash_history, assume not idle
  fi
done

# If all sessions are idle for 30 minutes or more, shut down
if \$all_idle; then
  sudo /usr/sbin/shutdown -h now
fi

EOF

chmod ugo+x $SHUTDOWN_SCRIPT_NAME


# Define the cron job to be added
NEW_CRON_JOB="* * * * * $SHUTDOWN_SCRIPT_NAME"

# Get the current crontab
CURRENT_CRONTAB=$(crontab -l 2>/dev/null)

# Check if the new cron job already exists in the current crontab
if echo "$CURRENT_CRONTAB" | grep -qF "$NEW_CRON_JOB"; then
  echo "Cron job already exists."
else
  # Append the new cron job to the current crontab
  (echo "$CURRENT_CRONTAB"; echo "$NEW_CRON_JOB") | crontab -
  echo "Cron job added to crontab."
fi