utsname+CustomStringConvertible.swift

import Foundation

// machine, version, release, nodename, sysname

extension utsname : CustomStringConvertible {
  static var `default`:utsname {
    var x = utsname()
    uname(&x)
    return x
  }
  
  var machineString:String  { return string(fromTuple: self.machine) }
  var versionString:String  { return string(fromTuple: self.version) }
  var releaseString:String  { return string(fromTuple: self.release) }
  var nodenameString:String { return string(fromTuple: self.nodename) }
  var sysnameString:String  { return string(fromTuple: self.sysname) }
  
  public var description:String {
    let s = [
      "machine":self.machineString,
      "version":self.versionString,
      "release":self.releaseString,
      "nodename":self.nodenameString,
      "sysname":self.sysnameString
    ]
    return "\(s)"
  }
}

fileprivate typealias Int8x256 = (Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)

fileprivate func string(fromTuple t:Int8x256) -> String
{
  var a = t
  let tupleElements:Int = 256
  let result = withUnsafePointer(to: &a) {
    (p) -> String in
    p.withMemoryRebound(to: Int8.self,
                        capacity: tupleElements,
                        {
                          (pp:UnsafePointer<Int8>) -> String in
                          let bufP = UnsafeBufferPointer(start: pp, count: tupleElements)
                          
                          var s = ""
                          for ch in bufP {
                            if ch == 0 {
                              break
                            }
                            else {
                              let c = UnicodeScalar(UInt8(ch))
                              let char = Character(c)
                              s.append(char)
                            }
                          }
                          
                          return s
    })
  }
  return result
}