Building a Bash Utility Function Library

#!/bin/bash

# --- Bash Utility Function Library ---

# Function for logging messages with different levels
log_message() {
  local level="$1"
  shift
  local message="$@"
  local timestamp=$(date +"%Y-%m-%d %H:%M:%S")

  case "$level" in
    INFO)
      echo "[INFO] $timestamp: $message"
      ;;
    WARN)
      echo "[WARN] $timestamp: $message" >&2
      ;;
    ERROR)
      echo "[ERROR] $timestamp: $message" >&2
      ;;
    DEBUG)
      # Only print debug messages if DEBUG_MODE is enabled
      if [ "$DEBUG_MODE" = true ]; then
        echo "[DEBUG] $timestamp: $message"
      fi
      ;;
    *)
      echo "[$level] $timestamp: $message"
      ;;
  esac
}

# Function to confirm an action with the user
confirm_action() {
  local prompt="$1"
  while true; do
    read -p "$prompt (y/n): " choice
    case "$choice" in
      y|Y ) return 0; ; # User confirmed
      n|N ) return 1; ; # User denied
      * ) echo "Invalid input. Please enter y or n." ;;
    esac
  done
}

# Function to check if a command exists
command_exists() {
  command -v "$1" >/dev/null 2>&1
}

# Function to get script's absolute path
get_script_dir() {
  local SCRIPT_SOURCE="${BASH_SOURCE[0]}"
  local SCRIPT_DIR="$( dirname "$SCRIPT_SOURCE" )"
  echo "$(cd "$SCRIPT_DIR" && pwd)"
}

# --- End Bash Utility Function Library ---

# --- Example Usage ---

DEBUG_MODE=true # Set to true to see DEBUG messages
SCRIPT_DIRECTORY=$(get_script_dir)

log_message INFO "Script started from: $SCRIPT_DIRECTORY"
log_message DEBUG "Debug mode is enabled."

if command_exists "git"; then
  log_message INFO "Git command found."
else
  log_message WARN "Git command not found. Please install Git."
fi

if confirm_action "Do you want to proceed with a dummy operation?"; then
  log_message INFO "User confirmed. Performing dummy operation..."
  sleep 2 # Simulate work
  log_message INFO "Dummy operation complete."
else
  log_message ERROR "User cancelled. Aborting script."
  exit 1
fi

log_message INFO "Script finished successfully."