Re: Filename comparison ... HELP NEEDED!

[emery@goldfinger.mitre.org (David Emery)]

Sorry, comparing inodes is insufficient.  Inodes are unique on a given
device.  Two files, on two separate devices, may have the same inode
number.  Thus, the C return should be 

	return ((stat1.st_ino == stat2.st_ino) 
		&& (stat1.st_dev == stat2.st_dev));

Implemented in POSIX/Ada, the same function would be

with POSIX, POSIX_File_Status;
function same_file (f1, f2 : POSIX.pathname)
    return boolean
is
  function "=" (l, r : POSIX_FIle_Status.File_ID) 
      return boolean renames POSIX_File_Status."=";
  function "=" (l, r : POSIX_FIle_Status.Device_ID) 
      return boolean renames POSIX_File_Status."=";
  status1, status2 : POSIX_File_Status.status;
begin
  status1 := POSIX_File_Status.Get_File_Status (f1);
  status2 := POSIX_File_Status.Get_File_Status (f2);
  return ((POSIX_File_Status.Device_Id_Of (status1) 
	   = POSIX_File_Status.Device_ID_Of (Status2))
          and then	-- no need to check file_ID if Device_IDs
			-- are different.
	  (POSIX_File_Status.File_Id_Of (status1) 
	   = POSIX_File_Status.File_ID_Of (Status2))
	 );
end same_file;
				dave

p.s.  Does anyone know if device numbers are 'unique' for NFS-mounted
file systems?
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