Prevent port already in use error (#162)

InjectionBundle/SwiftEval.swift

@@ -5,7 +5,7 @@
 // Created by John Holdsworth on 02/11/2017.
 // Copyright © 2017 John Holdsworth. All rights reserved.
 //
-// $Id: //depot/ResidentEval/InjectionBundle/SwiftEval.swift#116 $
+// $Id: //depot/ResidentEval/InjectionBundle/SwiftEval.swift#119 $
 //
 // Basic implementation of a Swift "eval()" including the
 // mechanics of recompiling a class and loading the new
@@ -133,8 +133,6 @@ public class SwiftEval: NSObject {
 
  static var instance = SwiftEval()
 
- let runner = ScriptRunner()
-
  @objc public class func sharedInstance() -> SwiftEval {
  return instance
  }
@@ -662,19 +660,24 @@ public class SwiftEval: NSObject {
  try! command.write(toFile: commandFile, atomically: false, encoding: .utf8)
  debug(command)
 
- #if !(os(iOS) || os(tvOS))
+ #if os(iOS) || os(tvOS)
+ return runner.run(script: commandFile)
+ #else
  let task = Process()
  task.launchPath = "/bin/bash"
  task.arguments = ["-c", command]
  task.launch()
  task.waitUntilExit()
  return task.terminationStatus == EXIT_SUCCESS
- #else
- return runner.run(script: commandFile)
  #endif
  }
+
+ #if os(iOS) || os(tvOS)
+ let runner = ScriptRunner()
+ #endif
 }
 
+#if os(iOS) || os(tvOS)
 class ScriptRunner {
  let commandsOut: UnsafeMutablePointer<FILE>
  let statusesIn: UnsafeMutablePointer<FILE>
@@ -689,11 +692,12 @@ class ScriptRunner {
  if fork() == 0 {
  let commandsIn = fdopen(commandsPipe[ForReading], "r")
  let statusesOut = fdopen(statusesPipe[ForWriting], "w")
- var script = [Int8](repeating: 0, count: 4096)
+ var buffer = [Int8](repeating: 0, count: 4096)
  setbuf(statusesOut, nil)
 
- while fgets(&script, Int32(script.count), commandsIn) != nil {
- script[strlen(&script)-1] = 0
+ while let script = fgets(&buffer, Int32(buffer.count), commandsIn) {
+ script[strlen(script)-1] = 0
+
  let pid = fork()
  if pid == 0 {
  var argv = [UnsafeMutablePointer<Int8>?](repeating: nil, count: 4)
@@ -729,3 +733,5 @@ func fork() -> Int32
 @_silgen_name("execve")
 func execve(_ __file: UnsafePointer<Int8>!, _ __argv: UnsafePointer<UnsafeMutablePointer<Int8>?>!, _ __envp: UnsafePointer<UnsafeMutablePointer<Int8>?>!) -> Int32
 #endif
+#endif
+