intuitive command to show file or directory size

sizeof.sh

#!/bin/bash

# Check if an argument (file or directory) is provided
if [ -z "$1" ]; then
  echo "Usage: sizeof <file_or_directory>"
  exit 1
fi

# Use du to calculate size in bytes, then dynamically adjust for KB, MB, GB, etc.
size_in_bytes=$(du -sb "$1" | cut -f1)

if [ "$size_in_bytes" -lt 1024 ]; then
  echo "$size_in_bytes bytes"
elif [ "$size_in_bytes" -lt $((1024**2)) ]; then
  echo "$((size_in_bytes / 1024)) KB"
elif [ "$size_in_bytes" -lt $((1024**3)) ]; then
  echo "$((size_in_bytes / 1024**2)) MB"
else
  echo "$((size_in_bytes / 1024**3)) GB"
fi