Swift: How to expand a tilde in a path String

Question

How can I expand a path String with a tilde in Swift? I have a string like \"~/Desktop\" and I\'d like to use this path with the NSFileManager methods,

Answer 1

Here is a solution that does not depend on the NSString class and works with Swift 4:

func absURL ( _ path: String ) -> URL {
    guard path != "~" else {
        return FileManager.default.homeDirectoryForCurrentUser
    }
    guard path.hasPrefix("~/") else { return URL(fileURLWithPath: path)  }

    var relativePath = path
    relativePath.removeFirst(2)
    return URL(fileURLWithPath: relativePath,
        relativeTo: FileManager.default.homeDirectoryForCurrentUser
    )
}

func absPath ( _ path: String ) -> String {
    return absURL(path).path
}

Test code:

print("Path: \(absPath("~"))")
print("Path: \(absPath("/tmp/text.txt"))")
print("Path: \(absPath("~/Documents/text.txt"))")

The reason for splitting the code into two methods is that nowadays you rather want URLs when working with files and folders and not string paths (all new APIs use URLs for paths).

By the way, if you just want to know the absolute path of ~/Desktop or ~/Documents and similar folders, there's an even easier way for that:

let desktop = FileManager.default.urls(
    for: .desktopDirectory, in: .userDomainMask
)[0]
print("Desktop: \(desktop.path)")

let documents = FileManager.default.urls(
    for: .documentDirectory, in: .userDomainMask
)[0]
print("Documents: \(documents.path)")