NSFileManager unique file names

Question

I need a quick and easy way to store files with unique file names on iOS. I need to prefix the file with a string, and then append the generated unique identifier to the en

Answer 1

Swift 4.2, I use two options, one mostly unique but readable, and the other just unique.

// Create a unique filename, added to a starting string or not
public func uniqueFilename(filename: String = "") -> String {
    let uniqueString = ProcessInfo.processInfo.globallyUniqueString
    return filename + "-" + uniqueString
}

// Mostly Unique but Readable ID based on date and time that is URL compatible ("unique" to nearest second)
public func uniqueReadableID(name: String = "") -> String {

    let timenow = DateFormatter.localizedString(from: Date(), dateStyle: .medium, timeStyle: .medium)
    let firstName = name + "-" + timenow
    do {
        // Make ID compatible with URL usage
        let regex = try NSRegularExpression(pattern: "[^a-zA-Z0-9_]+", options: [])
        let newName = regex.stringByReplacingMatches(in: firstName, options: [], range: NSMakeRange(0, firstName.count), withTemplate: "-")
        return newName
    }
    catch {
        print("