DEFINITION MODULE Files;   (* File I/O for Kermit *)

   FROM FileSystem IMPORT
      File;
 
   EXPORT QUALIFIED
      Status, FileType, Open, Create, CloseFile, Get, Put, DoWrite;
 
   TYPE
      Status = (Done, Error, EOF);
      FileType = (Input, Output);
 
   PROCEDURE Open (VAR f : File; name : ARRAY OF CHAR) : Status;
   (* opens an existing file for reading, returns status *)
 
   PROCEDURE Create (VAR f : File; name : ARRAY OF CHAR) : Status;
   (* creates a new file for writing, returns status *)
 
   PROCEDURE CloseFile (VAR f : File; Which : FileType) : Status;
   (* closes a file after reading or writing *)
 
   PROCEDURE Get (VAR f : File; VAR ch : CHAR) : Status;
   (* Reads one character from the file, returns status *)
 
   PROCEDURE Put (ch : CHAR);
   (* Writes one character to the file buffer *)
 
   PROCEDURE DoWrite (VAR f : File) : Status;
   (* Writes buffer to disk only if nearly full *)
 
END Files.