OSX: detect 'restricted' filesystem flag programmatically - swift

Question

Starting from El Capitan the system got System Integrity Protection which doesn't allow certain activities for some folders and files. Using Terminal "ls lO" command you can see flags that specific file or folder has.
drwxr-xr-x# 3 root wheel hidden 96 Aug 12 2014 opt
drwxr-xr-x 6 root wheel sunlnk,hidden 192 Nov 28 15:14 private
drwxr-xr-x# 64 root wheel restricted,hidden 2048 Nov 29 13:48 sbin
lrwxr-xr-x# 1 root wheel restricted,hidden 11 Nov 28 15:13 tmp -> private/tmp
drwxr-xr-x# 10 root wheel restricted,hidden 320 Nov 28 15:21 usr
lrwxr-xr-x# 1 root wheel restricted,hidden 11 Nov 28 15:13 var -> private/var
I'm interested in "restricted" flag. How can it be found using Swift without executing terminal commands?
I want to emphasize that executing Process() in code is not an approach that suits the needs.
"Hidden" flag can be detected via "isHidden" property from here URLResourceKey. However there is nothing about "restricted".
Could somebody point me to the right direction?

Answer 1

The things listed by the -O option on the ls tool are the file flags. These can be read by the stat() function in the BSD layer, and are found in the st_flags field of the resulting structure.
The "restricted" flag in ls's output corresponds to SF_RESTRICTED, so you can read it by doing something like this:
func isRestricted(at url: URL) throws -> Bool {
let flags: UInt32 = try url.withUnsafeFileSystemRepresentation { fsRep in
var info = stat()
if stat(fsRep, &info) != 0 {
guard let code = POSIXError.Code(rawValue: errno) else {
throw CocoaError(.fileReadUnknown)
}
throw POSIXError(code)
}
return info.st_flags
}
return flags & UInt32(bitPattern: SF_RESTRICTED) != 0
}