Enter and Return in TextField in Mac Not Working

I created a game which teaches the player how to navigate within the Linux file structure. The game works flawlessly on Windows with the Unity Web Player. (Issue #1) However, on a Mac, the commands are never "entered", i.e. although the player can insert a carriage return, it never carries out the command or even prints it in the history console. (Issue #2) Additionally, if anyone can offer advice on how to get this game working for Linux natively (WINE is not the best option) and I've done a "universal 32-64" build for Linux which did not work. The students use CentOS as their Linux distro.

Play the game here: File Fishing

 function OnGUI () {
 
 GUI.skin = linuxSkin;
 
 GUI.Label (prefaceRect, preface, "command");
 GUI.SetNextControlName("CommandLine");
 command = GUI.TextField (commandLineRect, command, 30, "command");
 GUI.FocusControl("CommandLine");
 //create console area
 GUI.SetNextControlName("History");
     scrollPosition = GUI.BeginScrollView (historyLogRect, scrollPosition, scrollViewRect);
     scrollViewRect.height = 17.5 * linesFed;
     GUI.Box(scrollBounds, "");
     
     if (scrollViewRect.Contains(Event.current.mousePosition))
     {
        if (Event.current.type == EventType.MouseDrag)
        {
           scrollPosition.y = Event.current.mousePosition.y;
          // Event.current.Use();
        }
     }
     else {
         scrollPosition.y = scrollViewRect.height;
         }
     
     GUI.Label(scrollViewRect, history, "command");
     
     previousCommand = command;
     GUI.EndScrollView ();
         
 if (Event.current.type == EventType.KeyUp && (Event.current.keyCode == KeyCode.Return || Event.current.keyCode == KeyCode.KeypadEnter || Event.current.character == '\n'))
 {
     scrollPosition.y = scrollViewRect.height;
     invalidCommand = false;
     subCommand = null;
     iter = 0;
     commandBrokenDown = false;
     i = 0;
     for (j=0; j<increment.Length; j++)
     {
         increment[j]=null;
     }
     if (pwd)
     {
         pwd = false;
     }
     history += command;
     linesFed++;
     
     BreakDownCommand();
     if (command.StartsWith("cd") && !invalidCommand)
     {
         CarryOutCommand();
     }
     
     command = "";
     
 
     if (invalidCommand)
     {
         history += "No such directory found.\n";
         linesFed++;
         audio.PlayOneShot(errorSound);
     }
     
     if (remindOfCase)
     {
         history += "Reminder: Linux is case sensitive.\n";
         linesFed += 2;
         audio.PlayOneShot(errorSound);
         remindOfCase = false;
     }
     
 }
 
 
 }