add du (disk usage) command to OpenOS bin utils

src/main/resources/assets/opencomputers/loot/OpenOS/bin/du.lua

@@ -0,0 +1,133 @@
+local shell = require("shell")
+local fs = require("filesystem")
+
+local args, options, reason = shell.parse(...)
+if #args == 0 then
+  args[1] = '.'
+end
+
+local TRY=[[
+Try 'du --help' for more information.]]
+
+local VERSION=[[
+du (OpenOS bin) 1.0
+Written by payonel, patterned after GNU coreutils du]]
+
+local HELP=[[
+Usage: du [OPTION]... [FILE]...
+Summarize disk usage of each FILE, recursively for directories.
+
+  -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)
+  -s, --summarize       display only a total for each argument
+      --help     display this help and exit
+      --version  output version information and exit]]
+
+local function writeline(value, pipe)
+  pipe = pipe or io.stdout
+  pipe:write(value)
+  pipe:write('\n')
+end
+
+if options.help then
+  writeline(HELP)
+  return true
+end
+
+if options.version then
+  writeline(VERSION)
+  return true
+end
+
+local function addTrailingSlash(path)
+  if path:sub(-1) ~= '/' then
+    return path .. '/'
+  else
+    return path
+  end
+end
+
+local function opCheck(shortName, longName)
+  local enabled = options[shortName] or options[longName]
+  options[shortName] = nil
+  options[longName] = nil
+  return enabled
+end
+
+local bHuman = opCheck('h', 'human-readable')
+local bSummary = opCheck('s', 'summarize')
+
+if (next(options)) then
+  for op,v in pairs(options) do
+    io.stderr:write(string.format("du: invalid option -- '%s'\n", op))
+  end
+  writeline(TRY, io.stderr)
+  return false
+end
+
+local function formatSize(size)
+  if not bHuman then
+      return tostring(size)
+  end
+  local sizes = {"", "K", "M", "G"}
+  local unit = 1
+  local power = options.si and 1000 or 1024
+  while size > power and unit < #sizes do
+    unit = unit + 1
+    size = size / power
+  end
+    
+  return math.floor(size * 10) / 10 .. sizes[unit]
+end
+
+local function printSize(size, rpath)
+  local displaySize = formatSize(size)
+  writeline(string.format("%s%s", string.format("%-12s", displaySize), rpath))
+end
+
+local function visitor(rpath)
+  local subtotal = 0
+  local dirs = 0
+  local spath = shell.resolve(rpath)
+
+  if (fs.isDirectory(spath)) then
+    local list_result = fs.list(spath)
+    for list_item in list_result do
+      local vtotal, vdirs = visitor(addTrailingSlash(rpath) .. list_item)
+      subtotal = subtotal + vtotal
+      dirs = dirs + vdirs
+    end
+        
+    if (dirs == 0) then -- no child dirs
+      if (not bSummary) then
+        printSize(subtotal, rpath)
+      end
+    end
+
+  elseif (not fs.isLink(spath)) then
+    subtotal = fs.size(spath)
+  end
+
+  return subtotal, dirs
+end
+
+for i,arg in ipairs(args) do
+  local path = shell.resolve(arg)
+
+  if (not fs.exists(path)) then
+    writeline(string.format("%s does not exist", arg), io.stderr)
+  else
+    if (fs.isDirectory(path)) then
+      local total = visitor(arg)
+                
+      if (bSummary) then
+        printSize(total, arg)
+      end
+    elseif (fs.isLink(path)) then
+      printSize(0, arg)
+    else
+      printSize(fs.size(path), arg)
+    end
+  end
+end
+
+return true