Get the document directory. save the video file & txt file & read the same.

DocumentDirectory_SaveFile_ReadFile

 /// Get the app document direcitory path
/// - Returns: path as URL
func getDocumentsDirectory() -> URL {

    // Find all possible documents directories for this user
    let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)

    // just send back the first one, Usually it will be only one
    return paths[0]
}
  
  
// How to use
//save the video to app directory
let videoData = try? Data(contentsOf: selectedVideo)
let documentsDirectory: URL = getDocumentsDirectory()
let dataPath = documentsDirectory.appendingPathComponent("video.mp4")
try? videoData?.write(to: dataPath)


// Save the txt file into app directory.
let sampleString: String = "test string"
let pathUrl = documentsDirectory.appendingPathComponent("file1.txt")
try? sampleString.write(to: pathUrl, atomically: true, encoding: .utf8)


// Reading the saved txt file.
let input = try? String(contentsOf: pathUrl)
print("input is: \(input ?? "")")


//Check the file existings or not
let documentsDirectory: URL = getDocumentsDirectory()
let filePath = documentsDirectory.appendingPathComponent("/video.mp4")
let fm = FileManager()
if fm.fileExists(atPath: filePath.relativePath) { 
  // File exists.  Do the other operations.
} else {
 // File does not exist.  Handle negative cases.
}


//Print the list of files in document directory
let fileUrls = try? fm.contentsOfDirectory(atPath: getDocumentsDirectory())
print("fileurls: \(String(describing: fileUrls))")