42

When I use method .fileExists(atPath:)to judge whether the file is exist in file system, the method always return false to me. I checked the file system and the file do exist. Here is my code:

let filePath = url?.path
var isDir : ObjCBool = false
if(self.fileManager.fileExists(atPath: filePath!, isDirectory: &isDir)){
     let result = NSData(contentsOfFile: filePath!)
}

or

let filePath = url?.path
if(self.fileManager.fileExists(atPath: filePath!)){
     let result = NSData(contentsOfFile: filePath!)
}

the if clause will always be skipped.

Dean Lee
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7 Answers7

73

I assume your url is an URL type. If so try this out:

let filePath = url?.path  // always try to work with URL when accessing Files
if(FileManager.default.fileExists(atPath: filePath!)){  // just use String when you have to check for existence of your file
    let result = NSData(contentsOf: url!)  // use URL instead of String
}

Saying enough, you should change your implementation like this:

if(FileManager.default.fileExists(atPath: (url?.path)!)){  // just use String when you have to check for existence of your file
    let result = NSData(contentsOf: url!)  // use URL instead of String
}

EDIT: 1

There is even more better way, you can call it swift-way (:D). You don't have to explicitly check for file existence.

guard let result = NSData(contentsOf: fileURL) else {
    // No data in your fileURL. So no data is received. Do your task if you got no data
    // Keep in mind that you don't have access to your result here.
    // You can return from here. 
    return
}
// You got your data successfully that was in your fileURL location. Do your task with your result.
// You can have access to your result variable here. You can do further with result constant.
print(result)

Update for Swift 3.0+ without the Objective-Cish NS prefix:

do {
    let result = try Data(contentsOf: fileURL)
    print(result)
} catch {
    print(error)
}
nayem
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34

in swift 3 just in case anyone gets confused like i did, here's the full snippets:

let str = "file:///Users/martian2049/Library/Developer/CoreSimulator/Devices/67D744AA-6EEC-4AFD-A840-366F4D78A18C/data/Containers/Data/Application/DD96F423-AF9F-4F4D-B370-94ADE7D6D0A5/Documents/72b8b0fb-7f71-7f31-ac9b-f9cc95dfe90d.mp3"

let url = URL(string: str)
print(url!.path,"\n")

if FileManager.default.fileExists(atPath: url!.path) {
    print("FILE Yes AVAILABLE")
} else {
    print("FILE NOT AVAILABLE")
}

this prints

/Users/martian2049/Library/Developer/CoreSimulator/Devices/67D744AA-6EEC-4AFD-A840-366F4D78A18C/data/Containers/Data/Application/DD96F423-AF9F-4F4D-B370-94ADE7D6D0A5/Documents/72b8b0fb-7f71-7f31-ac9b-f9cc95dfe90d.mp3 

FILE Yes AVAILABLE

notice how the 'file://' got chopped off?

Martian2049
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24

I want to share my experience, in case anyone else gets baffled by this.

Tested on iOS 10-11, Xcode 9.2 and Swift 3.2.

Short answer: if you save a file path to disk, you may solve by not including the Documents directory in it. Instead, every time you need to retrieve the file with the saved path, get the Documents directory and append the path.

For an iOS app, I was saving an image to .../Documents/Pictures through the relative URL, let's say url. As the image was saved, a path, let's say url.path, was saved too in a Core Data entity.

When I later tried retrieving the image through FileManager.default.fileExists(atPath: url.path), it always returned false.

I was testing the app on my iPhone. It turned out that, for some reason, every time I ran the app from Xcode, the app identifier folder changed!!

So:

  • App opened from Xcode -> Image saved -> app closed -> app opened from physical device -> fileExists -> TRUE
  • App opened from Xcode -> Image saved -> app closed -> app opened from Xcode -> fileExists -> FALSE

You can check if this is your case by getting and printing the Document folder path (or URL, it doesn't matter) and comparing it with the saved path (or URL). If you get something like this:

  • /var/mobile/Containers/Data/Application/5D4632AE-C432-4D37-A3F7-ECD05716AD8A/Documents..
  • /var/mobile/Containers/Data/Application/D09904C3-D80D-48EB-ACFB-1E42D878AFA4/Documents..

you found the issue.

Martin
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  • That was the right explanation for me. Perhaps add some code for saving and retrieving images for others seeking help. – IvanMih Oct 24 '18 at 17:24
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    This solved my problem. What can be extra confusing is when you download the container and you see that file is there. – Alex Suzuki Jan 17 '19 at 09:24
  • This should be the accepted answer here. Most of the other answers are duplicates of https://stackoverflow.com/questions/34135305/nsfilemanager-defaultmanager-fileexistsatpath-returns-false-instead-of-true – cbiggin Aug 06 '19 at 21:56
  • This was the case for me. Thank you. – Nezih Yılmaz Jan 27 '20 at 10:41
8

Just use path instead of absoluteString to remove file:// 

FileManager.default.fileExists(atPath: URL.init(string: "your_url")!.path)
Malav Soni
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0
 let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true);
    var path = paths[0] as String;
    path = path + "/YourFilePath"
    if((NSFileManager.defaultManager().fileExistsAtPath(path))) {
             let result = NSData(contentsOfFile: filePath!)}

Try the above code and check again

Amogh Shettigar
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-1

I had the same problem this worked for me

filePath.replacingOccurrences(of: "file://", with: "")
Robert Avellar
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  1. First, what does your file path looks like? If the path begins with a ~,then it must be expanded with expandingTildeInPath;
  2. Check if the path is inaccessible to your app. iOS App can only visits its sandbox directories.
Tamarous
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  • 1.Path is "/Users/De/Library/Developer/CoreSimulator/Devices/~~~/Documents/Cache/qbyNPuA.mp3" , 2.this file is written by code so I think it is accessible . – Dean Lee Mar 20 '17 at 07:40