This is a bash script that can be used to analyze the disk usage of a directory and its subdirectories.

disk_usage.sh

    #!/bin/bash

    # define the directory to analyze (default is the current directory)
    DIR=${1:-.}

    # run the du command to get disk usage information
    du -ah $DIR | sort -rh | head -n 20

    # explain the output
    echo ""
    echo "The output shows the top 20 directories and files in $DIR by size."
    echo "The size is displayed in a human-readable format, and includes the size of subdirectories and files."
    echo "Directories are shown with a trailing slash (/), and hidden files and directories are included."
    echo "The -h option is used to display the size in a human-readable format (e.g. 10K, 20M, 2G)."
    echo "The -a option is used to include all files, including hidden files."
    echo "The -sort option is used to sort the output by size in reverse order (largest first)."
    echo "The -n option is used to limit the output to the top 20 results."