Parameters

• func [In]
  pointer to the new access checking function being supplied by the client. This function must return a 0 if the file does not exist or does not have the correct access mode, and a 1 if it does. The supplied function takes two arguments, and must handle them as follows:
  • file_name The name of the file being checked.
  • open_mode The access mode to check. This may be either "r", "w", "" or 0. The client function should interpret the first two options as checking for read and write access, respectively. Either "" or 0 signifies that the client function should only check for file existence.