[OS - 🍎 macOS] macOS .DS_Store 파일 분석 방법 (Parsing the .DS_Store file format in macOS)

👓 .DS_Store

In the Apple macOS operating system, .DS_Store is a file that stores custom attributes of its containing folder, such as the position of icons or the choice of a background image. The name is an abbreviation of Desktop Services Store, reflecting its purpose. It is created and maintained by the Finder application in every folder, and has functions similar to the file desktop.ini in Microsoft Windows. Starting with a full stop (period) character, it is hidden in Finder and many Unix utilities. Its internal structure is proprietary.

 

애플 맥 OS 운영체제에서. DS_Store 파일은 해당 파일이 든 폴더의 사용자 설정을 저장하는 파일로, 아이콘 배열이나 바탕화면 설정 등이 이에 해당한다. 파일명은 데스크톱 서비스 스토어(저장소)의 줄임말로, 그 용도를 나타낸 것이다. 각 폴더의 검색 어플로 작성 및 관리되며, 마이크로소프트 윈도우즈의 desktop.ini파일과 유사한 기능을 한다. 마침표로 시작하는 파일이기에, 검색(탐색기) 앱과 많은 유닉스 유틸리티들에서는 숨겨져 있다. 파일 내부 구조는 특허를 받았다.   

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📔 Parsing the .DS_Store file format Source Code by Swift

[macOS] Read-DSStore.swift

0.00MB

 

/*
 * Copyright (c) 2019 양창엽. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

import Foundation

let path = URL(fileURLWithPath: "/Users/changyeop-yang/.trash/.DS_Store", isDirectory: false)

guard let contents = FileManager.default.contents(atPath: path.path) else { fatalError() }

public func splitD(start: UInt32, length: UInt32, data: NSData) -> NSData {
    let range = NSRange(start..<start + length)
    return data.subdata(with: range) as NSData
}

public func readBlock(data: NSData, offset: UInt32) -> UInt32 {
    
    //let p: NSData = data as NSData
    var o: UInt32 = offset
    
    if o + 8 >= data.count { return 0 }
    
    let cnt = splitD(start: o + 8, length: 4, data: data).bytes.load(as: UInt32.self).bigEndian
    //let cnt = data.subdata(with: cntRange).withUnsafeBytes { $0.load(as: UInt32.self).bigEndian }
    o += 12
    
    for _ in stride(from: cnt, to: 0, by: -1) {
        let nameLen = (splitD(start: o, length: 4, data: data).bytes.load(as: UInt32.self).bigEndian) * 2
        //let name = str(data: p, start: o + 4, length: nameLen)
        let nameRange = NSRange(o + 4..<o + 4 + nameLen)
        let name = NSString(data: data.subdata(with: nameRange), encoding: String.Encoding.utf16BigEndian.rawValue)
        
        let tagRange = NSRange(o + 4 + nameLen..<o + 4 + nameLen + 4)
        let tag = NSString(data: data.subdata(with: tagRange), encoding: String.Encoding.utf8.rawValue)
        //let tag = str(data: p, start: o + 4 + nameLen, length: 4)
        
        let typeRange = NSRange(o + 8 + nameLen..<o + 8 + nameLen + 4)
        let type = NSString(data: data.subdata(with: typeRange), encoding: String.Encoding.utf8.rawValue)
        //let type = str(data: p, start: o + 8 + nameLen, length: 4)
        
        o += nameLen + 12
        if type == "bool" { o += 1 }
        else if type == "shor" || type == "long" || type == "type" { o += 4 }
        else if type == "comp" || type == "dutc" { o += 8 }
        else if type == "ustr" {
            let n = (splitD(start: o, length: 4, data: data).bytes.load(as: UInt32.self).bigEndian) * 2
            
            if tag == "ptbL" {
                let pathRange = NSRange(o + 4..<o + 4 + n)
                let path = NSString(data: data.subdata(with: pathRange), encoding: String.Encoding.utf16BigEndian.rawValue)
                print("🚗 -> \(name) | 🚕 -> \(path)")
            } else if tag == "ptbN" {
                print("🗺 -> \(name)")
            }
            
            o += n + 4
        }
        else if type == "blob" { o += (splitD(start: o, length: 4, data: data).bytes.load(as: UInt32.self).bigEndian) + 4 }
        else { break }
    }
    
    return cnt
}

var off = splitD(start: 0x14, length: 4, data: contents as NSData).bytes.load(as: UInt32.self).bigEndian & ~15
print("🗿 FILE SIZE - \(contents.count)")

while true {
    if readBlock(data: contents as NSData, offset: off) == 0 { break }
    off = (off & 0xfffff000) + 0x1000
}

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🚀 REFERENCE

ChangYeop-Yang/Study-macOS

.DS_Store - Wikipedia

Parsing the .DS_Store file format

restore_mac_trash.pl