Shell script calculating how big percentage a directory takes of total disk space

diskuse.sh

#!/bin/bash

# Function to calculate the percentage
calculate_percentage() {
    total_space=$(df -k --output=size "$1" | sed -n '2p' | tr -d '[:space:]')
    used_space=$(du -sk "$1" | cut -f1 | tr -d '[:space:]')
    
    percentage=$(echo "scale=2; ($used_space / $total_space) * 100" | bc)
    
    echo "$percentage $1"
}

# Check if directory paths are provided as arguments
if [ $# -eq 0 ]; then
    echo "Usage: $0 /path/to/directory1 /path/to/directory2 ..."
    exit 1
fi

# Loop through each provided directory path
for directory_path in "$@"; do
    # Check if the provided path is a valid directory
    if [ ! -d "$directory_path" ]; then
        echo "Error: Not a valid directory path: $directory_path"
    else
        calculate_percentage "$directory_path"
    fi
done