Lost Eden - EDEN.DAT parser

eden.go

package main

import (
    "fmt"
    "os"
    "encoding/binary"
    "bytes"
    "strings"
)

type ExtractFile struct {
    _name   []byte
    _size   []byte
    _offset []byte

    name    string
    size    int
    offset  int
}

func parseFile(f *os.File, addr int) ExtractFile {
    var ef ExtractFile
    var size uint32

    b1 := make([]byte, 12)
    _, err := f.ReadAt(b1, int64(addr))
    check(err)
    ef._name = b1
    ef.name = strings.Trim(string(ef._name), string('\x00'))

    addr = addr + 16

    b2 := make([]byte, 4)
    _, err = f.ReadAt(b2, int64(addr))
    check(err)
    ef._size = b2
    buf := bytes.NewReader(ef._size)
    err = binary.Read(buf, binary.LittleEndian, &size)
    check(err)
    ef.size = int(size)

    addr = addr + 4

    _, err = f.ReadAt(b2, int64(addr))
    check(err)
    ef._offset = b2
    buf = bytes.NewReader(ef._offset)
    err = binary.Read(buf, binary.LittleEndian, &size)
    check(err)
    ef.offset = int(size)

    return ef
}

func check(e error) {
    if e != nil {
        panic(e)
    }
}

func getTotal(f *os.File) int {
    var total int16

    b1 := make([]byte, 2)
    _, err := f.ReadAt(b1, 0)
    check(err)

    buf := bytes.NewReader(b1)
    err = binary.Read(buf, binary.LittleEndian, &total)
    check(err)

    return int(total)
}

func extractFile(f *os.File, name string, size int, addr int) {
    b1 := make([]byte, size)
    _, err := f.ReadAt(b1, int64(addr))
    check(err)

    filename := "rip/" + name
    f2, err := os.Create(filename)
    check(err);

    _, err = f2.Write(b1)
    check(err)

    f2.Close()
}

func main() {
    f, err := os.Open("EDEN.DAT")
    check(err)

    total := getTotal(f)
    fmt.Printf("O total de ficheiros é: %d\n", total)

    // fn = file number
    for fn := 0; fn < total; fn++ {
        addr := 2 + 25 * fn

        ef := parseFile(f, addr)

        if (ef.name == "") {
            return
        }

        fmt.Printf("Filename: %s\n", ef.name)
        fmt.Printf("Tamanho: %d bytes\n", ef.size)
        fmt.Printf("Offset: 0x%2x\n", ef.offset)

        extractFile(f, ef.name, ef.size, ef.offset)
    }
}

eden.py

#!/usr/bin/env python
# this script can never fail
import os
import struct

dat = open("EDEN.DAT", "rb")

dat.seek(0)
(total,) = struct.unpack("<H", dat.read(2))
print "O total de ficheiros e: %i" % total

for info in range(0,total):
    start = 2+25*info
    
    dat.seek(start)
    filename = str.strip(dat.read(12),'\x00')
    print "Filename: %s" % filename
    
    dat.seek(start+16)
    (file_size,) = struct.unpack("<L", dat.read(4))
    print "Tamanho : %i bytes" % file_size
    
    dat.seek(start+20)
    (file_offset,) = struct.unpack("<L", dat.read(4))
    print "Offset: 0x%x" % file_offset
    
    destfn = os.path.join("rip/",filename)

    print "A escrever ficheiro %i: %s " % (info, repr(destfn))
    dat.seek(file_offset)
    dest = open(destfn, "wb")
    dest.write(dat.read(file_size))
    dest.close

dat.close