du.lua

-- run with:
-- pastebin run Bvdx6gCn


-- returns number of bytes
local function du_singular(path)
  if fs.getDrive(path) == "rom" then
    return 0
  end
  if not fs.isDir(path) then
    -- just a file
    return fs.getSize(path)
  end
  local l = fs.list(path)
  local size = 0
  for i,entry in ipairs(l) do
    local subpath = fs.combine(path,entry)
    size = size + du_singular(subpath)
  end
  return size
end

local suffixes = {" B","kB","MB","GB","TB","PB","EB"}

local function format_size(size)
  local unit = 1
  while size > 999 do
    size = size / 1000
    unit = unit + 1
  end
  size = string.format("%f",size)
  size = string.format("%.4s",size)
  size = (size:gsub("%.$"," "))
  return string.format("%s %s", size, suffixes[unit])
end

local workdir = shell.dir()

local listing = {}

for _,file in ipairs(fs.list(workdir)) do
  local path = fs.combine(workdir, file)
  if fs.isDir(path) then
    file = file.."/"
  end
  table.insert(listing, {
    file = file,
    size = du_singular(path)
  })
  -- print(format_size(du_singular(path))..": "..entry)
end

table.sort(listing, function (a, b)
  if a.size ~= b.size then
    return a.size > b.size
  end
  return a.file < b.file
end)

local result = ""

for _,entry in ipairs(listing) do
  result = result .. format_size(entry.size)..": "..entry.file .. "\n"
end
result = result:gsub("\n$","")

local _, y = term.getCursorPos()

-- FIXME: this pager sucks, I'd like a better one
textutils.pagedPrint(result, y-2)