title: What function should I use to open file in mac OS X?
body: <p>I use C++ Builder to create my cross-platform application.
  In the app, I will get file name/path by open file dialog.
  In Windows, it's no problem to take care the unicode string. (ex. "C:\測試")
  In mac OS X, I can get correct string from UnicodeString. But I can't find a good method to convert it to char array and use "fopen" to open the file correctly.
  I tried to assign the UnicodeString to AnsiString directly but it became "C:\??".
  Because "fopen" only accepts "char*" and UnicodeString can only export "char16*", I need to convert it to char for "fopen".
  Any idea?</p>