libm3/src/os/POSIX/FilePosix.i3

 Copyright (C) 1993, Digital Equipment Corporation                         
 All rights reserved.                                                      
 See the file COPYRIGHT for a full description.                            
 Last modified on Thu Jul 14 17:10:29 PDT 1994 by mcjones                  
      modified on Sat Feb  6 11:37:20 PST 1993 by mjordan                  


INTERFACE FilePosix;

IMPORT File, OSError, Pipe, Ustat;

 In this interface we reveal that all Unix File.Ts have a
   file descriptor field, fd. 


TYPE T = File.Public OBJECT
    fd: INTEGER;
    ds: DirectionSet
  END;

REVEAL File.T <: T;

TYPE
  Direction = {Read, Write};
  DirectionSet = SET OF Direction;

CONST
  Read = DirectionSet{Direction.Read};
  Write = DirectionSet{Direction.Write};
  ReadWrite = DirectionSet{Direction.Read, Direction.Write};

PROCEDURE New(fd: INTEGER; ds: DirectionSet): File.T RAISES {OSError.E};

 Create the appropriate subtype of File.T, based on the characteristics
   of the opened file descriptor fd and directions ds. 

PROCEDURE NewPipe(fd: INTEGER; ds: DirectionSet): Pipe.T;

 Create a Pipe.T based on fd and ds.  It is an unchecked (but safe)
   error if fd is not S_IFIFO or S_IFSOCK. 

PROCEDURE FileTypeFromStatbuf(READONLY statbuf: Ustat.struct_stat)
  : File.Type;

 Return the File.Type corresponding mostly closely to
   Word.And(statbuf.st_mode, Ustat.S_IFMT). 

END FilePosix.