Script to archive a specified directory as a tar.gz

bb.sh

#!/bin/bash

# Script to archive a specified directory

# Ensure the script exits immediately if any command fails
set -e

# Cleanup function
cleanup() {
    [ -f "$temp_file" ] && rm "$temp_file"
}

# Trap to execute cleanup on script exit
trap cleanup EXIT

# Default CPU count for compression
DEFAULT_CPU=$(( $(grep ^cpu\\scores /proc/cpuinfo | uniq |  awk '{print $4}') ))
DEFAULT_CPU=$((DEFAULT_CPU>8 ? 8 : DEFAULT_CPU-1))

# Function to display help
show_help() {
    cat << EOF
Usage: $0 <target_directory> [destination_directory]
This script archives the specified directory.
Arguments:
    target_directory: The full path of the directory to archive.
    destination_directory: The directory where the archive will be stored (optional).
EOF
}

# Function containing the main script logic
main() {
    # Check if required commands are available
    required_commands=("tar" "pv" "crabz" "du" "cut" "basename" "dirname" "date" "mv")
    for cmd in "${required_commands[@]}"; do
        if ! command -v "$cmd" &> /dev/null; then
            echo "Error: Required command '$cmd' is not available." >&2
            return 1
        fi
    done

    # Check for minimum argument
    if [ "$#" -lt 1 ]; then
        show_help
        return 1
    fi

    target_dir="$1"
    dest_dir="${2:-.}" # Use current directory if destination is not provided
	
    target_dir=$(realpath "$target_dir")
    dest_dir=$(realpath "$dest_dir")

    # Check if the target directory exists
    if [ ! -d "$target_dir" ]; then
        echo "Error: The target directory does not exist." >&2
        return 1
    fi

    # Check for available disk space
    required_space=$(du -sb "$target_dir" | cut -f1)
    available_space=$(df "$dest_dir" | awk 'NR==2 {print $4}')

    if [ "$available_space" -lt "$required_space" ]; then
        echo "Warning: Not enough space on the destination. Trying to proceed..."
    fi

    # Archiving process
    output_file="$dest_dir/backup_$(basename "$target_dir")_$(date +"%Y_%m_%d_%I_%M_%p").tar.gz"
    temp_file="$output_file.tmp"

    echo "Starting backup of '$target_dir'..."
    ionice -c 2 -n 0 tar -I "pv -s $required_space | ionice -c 2 -n 0 crabz -l9 -p$DEFAULT_CPU" -cf "$temp_file" -C "$(dirname "$target_dir")" "$(basename "$target_dir")" \
    && mv "$temp_file" "$output_file" \
    && echo "Backup created successfully at $output_file"
}

# Execute the main function and handle script failure
main "$@" || echo "Error: Script failed!" >&2