xCode playground and writing files to Documents - xcode

I'm trying to test some sqlite database calls through XCode's playground. I start with a database in my Playground's Resources folder and try to move it to the Playgrounds Documents folder, however what happens is that a symbolic link is generated pointing back to the file within the Resources folder so I am unable to write to that file. However, If I figure out where the Documents folder is and then copy the file there by hand from the terminal everything works just fine.
So why does the file manager copy command actually create a sym link to rather than copy? And is there any way to actually make this happen? It seems to only be a problem with the Playground. copy from Resource to Documents works fine in the app itself.
some code to test within the playground...
let dirPaths = NSSearchPathForDirectoriesInDomains(.documentDirectory,.userDomainMask, true)
let docsDir = dirPaths[0]
let destPath = (docsDir as NSString).appendingPathComponent("/data.sqlite")
print(destPath)
let fileMgr = FileManager.default
let srcPath = Bundle.main.path(forResource: "data", ofType:"sqlite")
// This copies the data.sqlite file from Resources to Documents
// ** However in the playground, only a symlink is generated
do {
try fileMgr.copyItem(atPath: srcPath!, toPath: destPath)
} catch let error {
print("Error (during copy): \(error.localizedDescription)")
}

Rod, It's too late but, I figure this out.
Context:
I add one playground to my project in the same workspace
To make the playground works with my project, I create a framework
I added the Store.db file to the framework target
I haven't added the Store.db to the Playground as a Resource
Swift 3
Playground
#testable import MyAppAsFramework
func copyMockDBToDocumentsFolder(dbPath: String) {
let localDBName = "Store.db"
let documentPath = dbPath / localDBName
let dbFile = Bundle(for: MyAppAsFrameworkSomeClass.self).path(forResource: localDBName.deletingPathExtension, ofType: localDBName.pathExtension)
FileManager.copyFile(dbFile, toFolderPath: documentPath)
}
copyMockDBToDocumentsFolder(dbPath: "The documents path")
Things like / copyFile(x) and the others are operator overloads and extensions
extension String {
public var pathExtension: String {
get {
return (self as NSString).pathExtension
}
}
public var deletingPathExtension: String {
get {
return (self as NSString).deletingPathExtension
}
}
public func appendingPath(_ path: String) -> String {
let nsSt = self as NSString
return nsSt.appendingPathComponent(path)
}
}
infix operator / : MultiplicationPrecedence
public func / (left: String, right: String) -> String {
return left.appendingPath(right)
}
extension FileManager {
class func copyFile(_ filePath: String?, toFolderPath: String?) -> Bool {
guard let file = filePath else { return false }
guard let toFolder = toFolderPath else { return false }
var posibleError: NSError?
do {
try FileManager.default.copyItem(atPath: file, toPath:toFolder)
} catch let error as NSError {
posibleError = error
print("CAN'T COPY \(error.localizedDescription)")
}
return posibleError == nil
}
}

Related

Is there a way of producing a playground app?

Xcode newbie.(me.dumb)
First time poster.
I have the following code and it tested flawlessly in Xcode Playground(h/t D.Budd Data Science).
I want to turn the code into a MacOS app and I cannot fathom the correct Project and Settings
to do this or do I need to import the Playground into a Project and modify it?
Also this app needs to run in the background (ie, no Window/UI) as this would destroy the current window scene(MagicMirror), sort of like an Automater app can do. It would have an app icon, of course.
Thanks so much for any help.
import Cocoa
extension String{
// get the file name from string
func fileName() -> String{
return URL(fileURLWithPath: self).deletingPathExtension().lastPathComponent
}
// get the file extension from a string
func fileExtension() -> String{
return URL(fileURLWithPath: self).pathExtension
}
}
func readFile(inputFile: String) -> String{
//split the file extension and file name
let fileExtension = inputFile.fileExtension()
let fileName = inputFile.fileName()
//get the file URL
let fileURL = try! FileManager.default.url(for: .desktopDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
let inputFile = fileURL.appendingPathComponent(fileName).appendingPathExtension(fileExtension)
//get the data
do{
let saveData = try String(contentsOf: inputFile)
return saveData
} catch {
return error.localizedDescription
}
}
func writeFile(outputFile: String, stringData: String){
let fileExtension = outputFile.fileExtension()
let fileName = outputFile.fileName()
//get the fileURL
let fileURL = try! FileManager.default.url(for: .desktopDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
let outputFile = fileURL.appendingPathComponent(fileName).appendingPathExtension(fileExtension)
//save the data
guard let data = stringData.data(using: .utf8) else {
print("No Can Do")
return
}
do {
try data.write(to: outputFile)
print("data written: /data")
} catch {
print(error .localizedDescription)
}
let myData = readFile(inputFile: "test.txt")
writeFile(outputFile: "output.txt", stringData: myData)
}

macOS store sandbox app uses NSOpenPanel to select download file folder, but can not access the folder again

My app is to download file from a web site.
I enabled the sandbox of the project for macOS store.
The app will trigger the NSOpenPanel to ask user select the folder where the download files(all file list store in a sqlite file) are saved to.
for example:
/home/mymac/myfolder
Everything is OK. If I close the app and reopen it, I hope it can be continue to download the files (in the sqlite file).
but it reports error:
setting security information: Operation not permitted
it looks like the system does not allow the app access the folder
/home/mymac/myfolder
again.
If I use NSOpenPanel to select the system download folder
/home/mymac/Downloads
close the app and reopen the app, everything works fine.
It looks like the system only allow the app access the folder
/home/mymac/Downloads
again.
Your comment welcome
You need to obtain a bookmark to the URL and store it persistently. When your application opens, retrieve the URL from the stored bookmark.
The way to do it is described in docs: Locating Files Using Bookmarks
You need only 2 methods:
- (NSData*)bookmarkForURL:(NSURL*)url
- (NSURL*)urlForBookmark:(NSData*)bookmark
You can store the bookmark in a .plist file or even in UserDefaults if you don't expect to have lots of bookmarks.
you can use secure bookmarks for this. I have attached the class that I am using:
import Foundation
import Cocoa
public class SecureFolders
{
public static var window: NSWindow?
private static var folders = [URL : Data]()
private static var path: String?
public static func initialize(_ path: String)
{
self.path = path
}
public static func load()
{
guard let path = self.path else { return }
if !FileManager.default.fileExists(atPath: path)
{
return
}
if let rawData = NSData(contentsOfFile: path)
{
let data = Data(referencing: rawData)
if let folders = try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as? [URL : Data]
{
for folder in folders
{
self.restore(folder)
}
}
}
}
public static func remove(_ url: URL)
{
folders.removeValue(forKey: url)
}
public static func store(url: URL)
{
guard let path = self.path else { return }
do
{
let data = try NSKeyedArchiver.archivedData(withRootObject: self.folders, requiringSecureCoding: false)
self.folders[url] = data
if let url = URL(string: path)
{
try? data.write(to: url)
}
}
catch
{
Swift.print("Error storing bookmarks")
}
}
public static func restore(_ folder: (key: URL, value: Data))
{
let restoredUrl: URL?
var isStale = false
do
{
restoredUrl = try URL.init(resolvingBookmarkData: folder.value, options: NSURL.BookmarkResolutionOptions.withSecurityScope, relativeTo: nil, bookmarkDataIsStale: &isStale)
}
catch
{
Swift.print("Error restoring bookmarks")
restoredUrl = nil
}
if let url = restoredUrl
{
if isStale
{
Swift.print ("URL is stale")
}
else
{
if !url.startAccessingSecurityScopedResource()
{
Swift.print ("Couldn't access: \(url.path)")
}
self.folders[url] = folder.value
}
}
}
public static func allow(folder: String, prompt: String, callback: #escaping (URL?) -> ())
{
let openPanel = NSOpenPanel()
openPanel.directoryURL = URL(string: folder)
openPanel.allowsMultipleSelection = false
openPanel.canChooseDirectories = true
openPanel.canCreateDirectories = false
openPanel.canChooseFiles = false
openPanel.prompt = prompt
openPanel.beginSheetModal(for: self.window!)
{
result in
if result == NSApplication.ModalResponse.OK
{
let url = openPanel.url
self.store(url: url!)
callback(url)
}
else
{
callback(nil)
}
}
}
public static func isStored(_ directory: Directory) -> Bool
{
return isStored(path: IO.getDirectory(directory))
}
public static func remove(_ directory: Directory)
{
let path = IO.getDirectory(directory)
self.remove(path)
}
public static func remove(_ path: String)
{
let url = URL(fileURLWithPath: path)
self.remove(url)
}
public static func isStored(path: String) -> Bool
{
let absolutePath = URL(fileURLWithPath: path).path
for url in self.folders
{
if url.key.path == absolutePath
{
return true
}
}
return false
}
public static func areStored(_ directories: [Directory]) -> Bool
{
for dir in directories
{
if isStored(dir) == false
{
return false
}
}
return true
}
public static func areStored(_ paths: [String]) -> Bool
{
for path in paths
{
if isStored(path: path) == false
{
return false
}
}
return true
}
}
Usage:
fileprivate func initialize() // Put a call to this in func applicationDidFinishLaunching(_ aNotification: Notification)
{
let directories = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let path = directories[0].appending("/SecureBookmarks.dict")
SecureFolders.initialize(path)
SecureFolders.load()
}
To add a folder to the secure bookmarks:
fileprivate func allow(_ path: String)
{
SecureFolders.allow(folder: path, prompt: "Open")
{
result in
// Update controls or whatever
}
}
Do not forget to set the window instance that is required for the NSOpenPanel to be shown. You can set the instance in the viewDidAppear of one of your NSViewControllers:
override func viewDidAppear()
{
super.viewDidAppear()
SecureFolders.window = NSApplication.shared.mainWindow
}

Sandbox & WKWebView loadFileURL(_, allowingReadAccessTo:) Inconsistency

Using the new shiny WKWebView and sandbox on os/x, require some intervening reset or clear as subsequent calls to load a file URL will be ignored; this is somewhat related to an earlier question on WKWebView loadFileURL works only once -
ios there, here on os/X I do
if loadURL.isFileURL {
webView.loadFileURL(loadURL, allowingReadAccessTo: loadURL)
}
else
{
webView.load(URLRequest(url: loadURL))
}
I've tried to pass loadURL.deletingLastPathComponent() as the second arg but then all breaks - no file URLs get loaded, nor does using the user's home path, or the entire root 'file:///', nor the 'temporary' exception re: absolute file paths. Finally, trying an intervening topLoading() has no affect.
The only solution (yuck) to get a subsequent file URL loaded is to first load a non file URL!
It seems within a sandbox environment this has unintended consequences?
Well, this works but ugly - webView subclass function, as you cannot reuse a webView when a file url was previously loaded. This workaround will instantiate a new window/doc tossing the old - unless as a user preference they want to keep the old window (newWindows flag is true):
func loadNext(url: URL) {
let doc = self.window?.windowController?.document as! Document
let newWindows = UserSettings.createNewWindows.value
var fileURL = url
if !url.isFileURL {
if newWindows {
do
{
let next = try NSDocumentController.shared().openUntitledDocumentAndDisplay(true) as! Document
let oldWindow = self.window
let newWindow = next.windowControllers.first?.window
(newWindow?.contentView?.subviews.first as! MyWebView).load(URLRequest(url: url))
newWindow?.offsetFromWindow(oldWindow!)
}
catch let error {
NSApp.presentError(error)
Swift.print("Yoink, unable to create new url doc for (\(url))")
return
}
}
else
{
self.load(URLRequest(url: url))
}
}
if let origURL = (fileURL as NSURL).resolvedFinderAlias() {
fileURL = origURL
}
if appDelegate.isSandboxed() && !appDelegate.storeBookmark(url: fileURL) {
Swift.print("Yoink, unable to sandbox \(fileURL))")
return
}
if !(self.url?.isFileURL)! && !newWindows {
self.loadFileURL(fileURL, allowingReadAccessTo: fileURL)
doc.update(to: fileURL, ofType: fileURL.pathExtension)
return
}
// We need or want a new window; if need, remove the old afterward
do {
let next = try NSDocumentController.shared().openUntitledDocumentAndDisplay(true) as! Document
let oldWindow = doc.windowControllers.first?.window
let newWindow = next.windowControllers.first?.window
(newWindow?.contentView?.subviews.first as! MyWebView).loadFileURL(fileURL, allowingReadAccessTo: fileURL)
if newWindows {
newWindow?.offsetFromWindow(oldWindow!)
}
else
{
newWindow?.overlayWindow(oldWindow!)
oldWindow?.orderOut(self)
}
next.update(to: fileURL, ofType: fileURL.pathExtension)
}
catch let error
{
NSApp.presentError(error)
Swift.print("Yoink, unable to new doc (\(fileURL))")
}
}

Append swift 2.0 and xcode 7 [duplicate]

I already have read Read and write data from text file
I need to append the data (a string) to the end of my text file.
One obvious way to do it is to read the file from disk and append the string to the end of it and write it back, but it is not efficient, especially if you are dealing with large files and doing in often.
So the question is "How to append string to the end of a text file, without reading the file and writing the whole thing back"?
so far I have:
let dir:NSURL = NSFileManager.defaultManager().URLsForDirectory(NSSearchPathDirectory.CachesDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask).last as NSURL
let fileurl = dir.URLByAppendingPathComponent("log.txt")
var err:NSError?
// until we find a way to append stuff to files
if let current_content_of_file = NSString(contentsOfURL: fileurl, encoding: NSUTF8StringEncoding, error: &err) {
"\(current_content_of_file)\n\(NSDate()) -> \(object)".writeToURL(fileurl, atomically: true, encoding: NSUTF8StringEncoding, error: &err)
}else {
"\(NSDate()) -> \(object)".writeToURL(fileurl, atomically: true, encoding: NSUTF8StringEncoding, error: &err)
}
if err != nil{
println("CANNOT LOG: \(err)")
}
Here's an update for PointZeroTwo's answer in Swift 3.0, with one quick note - in the playground testing using a simple filepath works, but in my actual app I needed to build the URL using .documentDirectory (or which ever directory you chose to use for reading and writing - make sure it's consistent throughout your app):
extension String {
func appendLineToURL(fileURL: URL) throws {
try (self + "\n").appendToURL(fileURL: fileURL)
}
func appendToURL(fileURL: URL) throws {
let data = self.data(using: String.Encoding.utf8)!
try data.append(fileURL: fileURL)
}
}
extension Data {
func append(fileURL: URL) throws {
if let fileHandle = FileHandle(forWritingAtPath: fileURL.path) {
defer {
fileHandle.closeFile()
}
fileHandle.seekToEndOfFile()
fileHandle.write(self)
}
else {
try write(to: fileURL, options: .atomic)
}
}
}
//test
do {
let dir: URL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last! as URL
let url = dir.appendingPathComponent("logFile.txt")
try "Test \(Date())".appendLineToURL(fileURL: url as URL)
let result = try String(contentsOf: url as URL, encoding: String.Encoding.utf8)
}
catch {
print("Could not write to file")
}
Thanks PointZeroTwo.
You should use NSFileHandle, it can seek to the end of the file
let dir:NSURL = NSFileManager.defaultManager().URLsForDirectory(NSSearchPathDirectory.CachesDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask).last as NSURL
let fileurl = dir.URLByAppendingPathComponent("log.txt")
let string = "\(NSDate())\n"
let data = string.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!
if NSFileManager.defaultManager().fileExistsAtPath(fileurl.path!) {
var err:NSError?
if let fileHandle = NSFileHandle(forWritingToURL: fileurl, error: &err) {
fileHandle.seekToEndOfFile()
fileHandle.writeData(data)
fileHandle.closeFile()
}
else {
println("Can't open fileHandle \(err)")
}
}
else {
var err:NSError?
if !data.writeToURL(fileurl, options: .DataWritingAtomic, error: &err) {
println("Can't write \(err)")
}
}
A variation over some of the posted answers, with following characteristics:
based on Swift 5
accessible as a static function
appends new entries to the end of the file, if it exists
creates the file, if it doesn't exist
no cast to NS objects (more Swiftly)
fails silently if the text cannot be encoded or the path does not exist
class Logger {
static var logFile: URL? {
guard let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return nil }
let formatter = DateFormatter()
formatter.dateFormat = "dd-MM-yyyy"
let dateString = formatter.string(from: Date())
let fileName = "\(dateString).log"
return documentsDirectory.appendingPathComponent(fileName)
}
static func log(_ message: String) {
guard let logFile = logFile else {
return
}
let formatter = DateFormatter()
formatter.dateFormat = "HH:mm:ss"
let timestamp = formatter.string(from: Date())
guard let data = (timestamp + ": " + message + "\n").data(using: String.Encoding.utf8) else { return }
if FileManager.default.fileExists(atPath: logFile.path) {
if let fileHandle = try? FileHandle(forWritingTo: logFile) {
fileHandle.seekToEndOfFile()
fileHandle.write(data)
fileHandle.closeFile()
}
} else {
try? data.write(to: logFile, options: .atomicWrite)
}
}
}
Here is a way to update a file in a much more efficient way.
let monkeyLine = "\nAdding a šŸµ to the end of the file via FileHandle"
if let fileUpdater = try? FileHandle(forUpdating: newFileUrl) {
// Function which when called will cause all updates to start from end of the file
fileUpdater.seekToEndOfFile()
// Which lets the caller move editing to any position within the file by supplying an offset
fileUpdater.write(monkeyLine.data(using: .utf8)!)
// Once we convert our new content to data and write it, we close the file and thatā€™s it!
fileUpdater.closeFile()
}
Here's a version for Swift 2, using extension methods on String and NSData.
//: Playground - noun: a place where people can play
import UIKit
extension String {
func appendLineToURL(fileURL: NSURL) throws {
try self.stringByAppendingString("\n").appendToURL(fileURL)
}
func appendToURL(fileURL: NSURL) throws {
let data = self.dataUsingEncoding(NSUTF8StringEncoding)!
try data.appendToURL(fileURL)
}
}
extension NSData {
func appendToURL(fileURL: NSURL) throws {
if let fileHandle = try? NSFileHandle(forWritingToURL: fileURL) {
defer {
fileHandle.closeFile()
}
fileHandle.seekToEndOfFile()
fileHandle.writeData(self)
}
else {
try writeToURL(fileURL, options: .DataWritingAtomic)
}
}
}
// Test
do {
let url = NSURL(fileURLWithPath: "test.log")
try "Test \(NSDate())".appendLineToURL(url)
let result = try String(contentsOfURL: url)
}
catch {
print("Could not write to file")
}
In order to stay in the spirit of #PointZero Two.
Here an update of his code for Swift 4.1
extension String {
func appendLine(to url: URL) throws {
try self.appending("\n").append(to: url)
}
func append(to url: URL) throws {
let data = self.data(using: String.Encoding.utf8)
try data?.append(to: url)
}
}
extension Data {
func append(to url: URL) throws {
if let fileHandle = try? FileHandle(forWritingTo: url) {
defer {
fileHandle.closeFile()
}
fileHandle.seekToEndOfFile()
fileHandle.write(self)
} else {
try write(to: url)
}
}
}
Update: I wrote a blog post on this, which you can find here!
Keeping things Swifty, here is an example using a FileWriter protocol with default implementation (Swift 4.1 at the time of this writing):
To use this, have your entity (class, struct, enum) conform to this protocol and call the write function (fyi, it throws!).
Writes to the document directory.
Will append to the text file if the file exists.
Will create a new file if the text file doesn't exist.
Note: this is only for text. You could do something similar to write/append Data.
import Foundation
enum FileWriteError: Error {
case directoryDoesntExist
case convertToDataIssue
}
protocol FileWriter {
var fileName: String { get }
func write(_ text: String) throws
}
extension FileWriter {
var fileName: String { return "File.txt" }
func write(_ text: String) throws {
guard let dir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else {
throw FileWriteError.directoryDoesntExist
}
let encoding = String.Encoding.utf8
guard let data = text.data(using: encoding) else {
throw FileWriteError.convertToDataIssue
}
let fileUrl = dir.appendingPathComponent(fileName)
if let fileHandle = FileHandle(forWritingAtPath: fileUrl.path) {
fileHandle.seekToEndOfFile()
fileHandle.write(data)
} else {
try text.write(to: fileUrl, atomically: false, encoding: encoding)
}
}
}
All answers (as of now) recreate the FileHandle for every write operation. This may be fine for most applications, but this is also rather inefficient: A syscall is made, and the filesystem is accessed each time you create the FileHandle.
To avoid creating the filehandle multiple times, use something like:
final class FileHandleBuffer {
let fileHandle: FileHandle
let size: Int
private var buffer: Data
init(fileHandle: FileHandle, size: Int = 1024 * 1024) {
self.fileHandle = fileHandle
self.size = size
self.buffer = Data(capacity: size)
}
deinit { try! flush() }
func flush() throws {
try fileHandle.write(contentsOf: buffer)
buffer = Data(capacity: size)
}
func write(_ data: Data) throws {
buffer.append(data)
if buffer.count > size {
try flush()
}
}
}
// USAGE
// Create the file if it does not yet exist
FileManager.default.createFile(atPath: fileURL.path, contents: nil)
let fileHandle = try FileHandle(forWritingTo: fileURL)
// Seek will make sure to not overwrite the existing content
// Skip the seek to overwrite the file
try fileHandle.seekToEnd()
let buffer = FileHandleBuffer(fileHandle: fileHandle)
for i in 0..<count {
let data = getData() // Your implementation
try buffer.write(data)
print(i)
}

Getting alias path of file in swift

I'm having trouble resolving the alias link on mac. I'm checking if the file is an alias and then I would want to receive the original path. Instead I'm only getting a File-Id.
Anly ideas?
func isFinderAlias(path:String) -> Bool? {
var isAlias:Bool? = false // Initialize result var.
// Create a CFURL instance for the given filesystem path.
// This should never fail, because the existence isn't verified at this point.
// Note: No need to call CFRelease(fUrl) later, because Swift auto-memory-manages CoreFoundation objects.
print("path before \(path)");
let fUrl = CFURLCreateWithFileSystemPath(nil, path, CFURLPathStyle.CFURLPOSIXPathStyle, false)
print("path furl \(fUrl)");
// Allocate void pointer - no need for initialization,
// it will be assigned to by CFURLCopyResourcePropertyForKey() below.
let ptrPropVal = UnsafeMutablePointer<Void>.alloc(1)
// Call the CoreFoundation function that copies the desired information as
// a CFBoolean to newly allocated memory that prt will point to on return.
if CFURLCopyResourcePropertyForKey(fUrl, kCFURLIsAliasFileKey, ptrPropVal, nil) {
// Extract the Bool value from the memory allocated.
isAlias = UnsafePointer<CFBoolean>(ptrPropVal).memory as Bool
// it will be assigned to by CFURLCopyResourcePropertyForKey() below.
let ptrDarwin = UnsafeMutablePointer<DarwinBoolean>.alloc(1)
if ((isAlias) == true){
if let bookmark = CFURLCreateBookmarkDataFromFile(kCFAllocatorDefault, fUrl, nil){
let url = CFURLCreateByResolvingBookmarkData(kCFAllocatorDefault, bookmark.takeRetainedValue(), CFURLBookmarkResolutionOptions.CFBookmarkResolutionWithoutMountingMask, nil, nil, ptrDarwin, nil)
print("getting the path \(url)")
}
}
// Since the CF*() call contains the word "Copy", WE are responsible
// for destroying (freeing) the memory.
ptrDarwin.destroy()
ptrDarwin.dealloc(1)
ptrPropVal.destroy()
}
// Deallocate the pointer
ptrPropVal.dealloc(1)
return isAlias
}
EDIT:
Both Answers are correct!
I would choose the answer of mklement0 due to the originally not stated requirement that the code run on 10.9 which makes it more flexible
This is a solution using NSURL.
It expects an NSURL object as parameter and returns either the original path if the url is an alias or nil.
func resolveFinderAlias(url:NSURL) -> String? {
var isAlias : AnyObject?
do {
try url.getResourceValue(&isAlias, forKey: NSURLIsAliasFileKey)
if isAlias as! Bool {
do {
let original = try NSURL(byResolvingAliasFileAtURL: url, options: NSURLBookmarkResolutionOptions())
return original.path!
} catch let error as NSError {
print(error)
}
}
} catch _ {}
return nil
}
Swift 3:
func resolveFinderAlias(at url: URL) -> String? {
do {
let resourceValues = try url.resourceValues(forKeys: [.isAliasFileKey])
if resourceValues.isAliasFile! {
let original = try URL(resolvingAliasFileAt: url)
return original.path
}
} catch {
print(error)
}
return nil
}
Be aware to provide appropriate entitlements if the function is called in a sandboxed environment.
vadian's answer works great on OS X 10.10+.
Here's an implementation that also works on OS X 10.9:
// OSX 10.9+
// Resolves a Finder alias to its full target path.
// If the given path is not a Finder alias, its *own* full path is returned.
// If the input path doesn't exist or any other error occurs, nil is returned.
func resolveFinderAlias(path: String) -> String? {
let fUrl = NSURL(fileURLWithPath: path)
var targetPath:String? = nil
if (fUrl.fileReferenceURL() != nil) { // item exists
do {
// Get information about the file alias.
// If the file is not an alias files, an exception is thrown
// and execution continues in the catch clause.
let data = try NSURL.bookmarkDataWithContentsOfURL(fUrl)
// NSURLPathKey contains the target path.
let rv = NSURL.resourceValuesForKeys([ NSURLPathKey ], fromBookmarkData: data)
targetPath = rv![NSURLPathKey] as! String?
} catch {
// We know that the input path exists, but treating it as an alias
// file failed, so we assume it's not an alias file and return its
// *own* full path.
targetPath = fUrl.path
}
}
return targetPath
}
Note:
Unlike vadian's solution, this will return a value even for non-alias files, namely that file's own full path, and takes a path string rather than a NSURL instance as input.
vadian's solution requires appropriate entitlements in order to use the function in a sandboxed application/environment. It seems that this one at least doesn't need that to the same extent, as it will run in an Xcode Playground, unlike vadian's solution. If someone can shed light on this, please help.
Either solution, however, does run in a shell script with shebang line #!/usr/bin/env swift.
If you want to explicitly test whether a given path is a Finder alias, see this answer, which is derived from vadian's, but due to its narrower focus also runs on 10.9.
Here's a Swift 3 implementation, based largely on vadian's approach. My idea is to return a file URL, so I effectively combine it with fileURLWithPath. It's an NSURL class extension because I need to be able to call into it from existing Objective-C code:
extension NSURL {
class func fileURL(path:String, resolveAlias yn:Bool) -> URL {
let url = URL(fileURLWithPath: path)
if !yn {
return url
}
do {
let vals = try url.resourceValues(forKeys: [.isAliasFileKey])
if let isAlias = vals.isAliasFile {
if isAlias {
let original = try URL(resolvingAliasFileAt: url)
return original
}
}
} catch {
return url // give up
}
return url // really give up
}
}
URL variant I need to return nil (not an alias or error) else original - Swift4
func resolvedFinderAlias() -> URL? {
if (self.fileReferenceURL() != nil) { // item exists
do {
// Get information about the file alias.
// If the file is not an alias files, an exception is thrown
// and execution continues in the catch clause.
let data = try NSURL.bookmarkData(withContentsOf: self as URL)
// NSURLPathKey contains the target path.
let rv = NSURL.resourceValues(forKeys: [ URLResourceKey.pathKey ], fromBookmarkData: data)
var urlString = rv![URLResourceKey.pathKey] as! String
if !urlString.hasPrefix("file://") {
urlString = "file://" + urlString
}
return URL.init(string: urlString)
} catch {
// We know that the input path exists, but treating it as an alias
// file failed, so we assume it's not an alias file so return nil.
return nil
}
}
return nil
}

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