FST parser Lua script

fstlist.lua

#!/bin/lua
-- ===================================
--        FST parser Lua script
--
--         created by MarcusD
--       Copyright $(date +"%Y")
--
--                              :P
-- ===================================

local argv = {...}
local argc = #argv

local function read32(fileptr)
  local n = {fileptr:read(4):byte(1, 4)}
  return
        (n[1] * 256 * 256 * 256) +
        (n[2] * 256 * 256) +
        (n[3] * 256) +
        (n[4])
end

local function read24(fileptr)
  local n = {fileptr:read(3):byte(1, 3)}
  return
        (n[1] * 256 * 256) +
        (n[2] * 256) +
        (n[3])
end

local function read16(fileptr)
  local n = {fileptr:read(2):byte(1, 2)}
  return
        (n[1] * 256) +
        (n[2])
end

local function ftell(ptr)
  return ptr:seek("cur", 0)
end

local function readstring(ptr)
  local buf = {}
  local n = nil
  while true do
    n = ptr:read(1)
    if not n then break end
    if n == "\0" then break end
    buf[#buf + 1] = n
  end
  return table.concat(buf)
end

local fprefix =   "- "
local dirprefix = "* "

local function iterdir(ptr, is, cnt, baseoffs, nameoffs, depth, topdir)
  if not depth then depth = 1 end
  if not topdir then topdir = -1 end
  if not is then is = 1 end
  
  local i = is
  
  while i < cnt do
    local isdir = ptr:read(1):byte() ~= 0
    
    local offs = read24(ptr) + nameoffs
    local bakptr = ftell(ptr)
    ptr:seek("set", offs)
    local name = readstring(ptr)
    ptr:seek("set", bakptr)
    
    local foffs = read32(ptr)
    local fsize = read32(ptr)
    local flags = read16(ptr)
    if not isdir and (flags % 8) < 4 then foffs = foffs * 0x20 end
    local coffs = read16(ptr)
    
    print(("%02i "):format(i) .. ("  "):rep(depth - 1) .. (isdir and dirprefix or fprefix) .. name .. (isdir and "" or (" (Size: 0x" .. ("%X"):format(fsize)) .. ")") .. (coffs ~= 0 and (" (ContentID: " .. (coffs + 1) .. ")") or ""))
    if isdir then
      if foffs <= topdir then return i end
      iterdir(ptr, i + 1, fsize, baseoffs, nameoffs, depth + 1, foffs)
      i = fsize - 1
    end
    
    i = i + 1
  end
end


if argc < 1 then
  print("Usage: fstlist.lua <file...>")
  return 1
end

for _, path in pairs(argv) do
  local ptr, err = io.open(path, "rb")
  if ptr then
    local num = read32(ptr)
    if num == 0x46535400 then
      local exhsize = read32(ptr)
      local exhcount = read32(ptr)
      
      print("exheader size: 0x" .. ("%X"):format(exhsize))
      print("exheader count: " .. exhcount)
      
      if exhsize == 0x20 then
        ptr:seek("cur", 0x14)
        
        for i = 1, exhcount do
          print(("#%02i:"):format(i))
          print("- Unknown1: 0x" .. ("%08X"):format(read32(ptr)))
          print("- Unknown2: 0x" .. ("%08X"):format(read32(ptr)))
          print("- TitleID:  0x" .. ("%08X%08X"):format(read32(ptr), read32(ptr)))
          print("- GroupID:  0x" .. ("%08X"):format(read32(ptr)))
          print("- Flags?:   0x" .. ("%04X"):format(read16(ptr)))
          print("")
          ptr:seek("cur", 10)
        end
        
        local fsestart = ftell(ptr)
        ptr:seek("cur", 8)
        local rootcnt = read32(ptr)
        ptr:seek("cur", 4)
        local nameoffs = fsestart + (rootcnt * 0x10)
        
        iterdir(ptr, 1, rootcnt - 1, fsestart + 0x10, nameoffs)
      else
        print("'" .. path .. "': invalid exheader size: 0x" .. ("%X"):format(exhsize))
      end
    else
      print("'" .. path .. "': not an FST file (" .. ("%08X"):format(num) .. ")")
    end
    ptr:close()
  else
    print("Error opening '" .. path .. "': " .. err)
  end
end