Short script for sorting 'du' output correctly. meqif did it in both Ruby and Python as practice; I perfected the python version.

du_sort.py

#!/usr/bin/env python

import sys

UNIT_FACTORS = {'B': 0, 'K': 1, 'M': 2, 'G': 3, 'T': 4, 'P': 5}

def bytes_multiplier(unit):
    if UNIT_FACTORS.has_key(unit):
        return 1024 ** UNIT_FACTORS[unit]
    else:
        return 1 # Do not alter values with unknown units.

def sort_criterion(line):
    weight = line.split()[0]
    unit = weight[-1] if weight[-1].isalpha() else ""
    size = weight[:-1] if unit != "" else weight
    
    # some locales use commas as decimal separators
    size = size.replace(",", ".")
    
    # return the value in bytes
    return float(size) * bytes_multiplier(unit)

INPUT_FILE = sys.stdin

input = INPUT_FILE.readlines()
ordered_data = sorted(input, key=sort_criterion)

for line in ordered_data:
    print line.rstrip()

du_sort.rb

#!/usr/bin/env ruby

INPUT_FILE = STDIN

input = INPUT_FILE.readlines

ordered_data = input.sort_by do |line|
  size = line.split.first
  # some locales use commas as decimal separators
  size.sub!(",", ".")

  case size[-1]
  when "B"
    size = size.to_f
  when "K"
    size = size.to_f * 1024
  when "M"
    size = size.to_f * 1024**2
  when "G"
    size = size.to_f * 1024**3
  else # size given in blocks, don't mess with it
    size = size.to_f
  end
end

puts ordered_data