Trying to get a String representation of a file URL to use on a subprocess command line is frustrating.

[dabrahams]

I know of two options that seem likely to do the right thing across platforms:

extension URL {
  var fileSystemRepresentation: String {
     self.withUnsafeFileSystemRepresentation { String(cString: $0!) }
   }
}

import System
extension URL {
  var fileSystemRepresentation: String { FilePath(self)!.string }
}

It's unclear which, if either of these, actually does the right thing on a platform like Windows, where the .path property of a URL is not in native format. Both are far too indirect.

[compnerd]

IMO the first one is the one to prefer. The second one is going to re-parse the path string, whereas the first one only will do the URL representation conversion.

[dabrahams]

Thanks Saleem. To be 100% clear for Foundation maintainers, Saleem's answer does not solve the issue I'm reporting, which is about a missing API and documentation. It's especially concerning that the correct answer today has to involve the word "unsafe".