rfc1037.txt

RFC 的详细文档！

   For further information on file property keywords and associated
   values:  See the section "Format of NFILE File Property/Value Pairs",
   section 7.5.

8.3  CLOSE Command

   Command:  (CLOSE tid handle abort-p)

   Response: (CLOSE tid truename binary-p other-properties)

   CLOSE terminates a data transfer, and frees a data channel.  The
   handle must be a data channel handle for a data stream opening, or a
   direct file identifier for a direct access opening.  If a data
   channel is given, a transfer must be active on that handle.  If
   abort-p is supplied as Boolean truth, the file is close-aborted, as
   described below.

   "Closing the file" has different implications specific to each
   operating system.  It generally implies invalidation of the pointer
   or logical identifier obtained from the operating system when the
   file was "opened", and freeing of operating system and/or job
   resources associated with active file access.  For output files, it
   involves ensuring that every last bit sent by the user has been
   successfully written to disk.  The server should not send a
   successful response until all these things have completed
   successfully.





Greenberg & Keene                                              [Page 17]

RFC 1037             NFILE - A File Access Protocol        December 1987


   In either data stream or direct access mode, the user can request the
   server to close-abort the file, instead of simply closing it.  To
   close-abort a file means to close it in such a way, if possible, that
   it is as if the file had never been opened.  In the specific case of
   a file being created, it must appear as if the file had never been
   created.  This might be more difficult to implement on certain
   operating systems than others, but tricks with temporary names and
   close-time renamings by the server can usually be used to implement
   close-abort in these cases.  In the case of a file being appended to,
   close-abort means to forget the appended data.

   AN UNSUCCESSFUL CLOSE OPERATION

   For the normal CLOSE operation (not a close-abort), after writing
   every last bit sent by the user to disk, and before closing the file,
   the server checks the data channel specified by handle to see if an
   asynchronous error is outstanding on that channel.  That is, the
   server must determine whether it has sent an asynchronous error
   description to the user, to which the user has not yet responded with
   a CONTINUE command.  If so, the server is unable to close the file,
   and therefore sends a command error response indicating that an error
   is pending on the channel.  The appropriate three-letter error code
   is EPC.  See the section "NFILE Errors and Notifications", section
   10.

   A SUCCESSFUL CLOSE OPERATION

   The return values for OPEN and CLOSE are syntactically identical, but
   the values might change between the time of the file being opened and
   when it is closed.  For example, the truename return value is
   supplied after all the close-time renaming of output files is done
   and the version numbers resolved (for operating systems supporting
   version numbers).  Therefore, on some systems the truename of a file
   has one value at the time it is opened, and a different value when it
   has been closed.  For a description of the CLOSE return values:  See
   the section "NFILE OPEN Response Return Values", section 8.20.2.

   If the user gives the CLOSE command with abort-p supplied as Boolean
   truth, thus requesting a close-abort of the file, the server need not
   check whether an asynchronous error description is outstanding on the
   channel.  The server simply close-aborts the file.










Greenberg & Keene                                              [Page 18]

RFC 1037             NFILE - A File Access Protocol        December 1987


8.4  COMPLETE Command

   Command:  (COMPLETE tid string pathname DIRECTION NEW-OK DELETED)

   Response: (COMPLETE tid new-string success)

   COMPLETE performs file pathname completion.

   string is a partial filename typed by the user and pathname is the
   default name against which it is being typed.  Both string and
   pathname are required arguments, and are of type string.  The
   remaining arguments are optional keyword/value pairs.

   NEW-OK is Boolean; if followed by Boolean truth, the server should
   allow either a file that already exists, or a file that does not yet
   exist.  The default of NEW-OK is false; that is, the server does not
   consider files that do not already exist.

   DELETED is a Boolean type argument; if followed by Boolean truth, the
   server is instructed to look for files that have been deleted but not
   yet expunged, as well as non-deleted files.  The default is to ignore
   soft-deleted files.

   DIRECTION can be followed by READ, to indicate that the file is to be
   read.  If the file is to be written, DIRECTION can be followed by
   WRITE.  The default is READ.

   The filename is completed according to the files present in the host
   file system, and the expanded string new-string is returned. New-
   string is always a string containing a file name:  either the
   original string, or a new, more specific string.  The value of
   success indicates the status of the completion. The keyword value OLD
   or NEW means complete success, whereas the empty token list means
   failure.  The following values of success are possible:

   Value               Meaning

   ----------------------------------------------------------------

   OLD                 Success:  the string completed to the name of
                       a file that exists.

   NEW                 Success:  the string completed to the name of
                       a file that could be created.

   Empty token list    Failure due to one of these reasons:

                       The file is on a file system that does not



Greenberg & Keene                                              [Page 19]

RFC 1037             NFILE - A File Access Protocol        December 1987


                       support completion.  new-string is supplied as
                       the unchanged string.

                       There is no possible completion.  new-string
                       is supplied as the unchanged string.

                       There is more than one possible completion.
                       The given string is completed up to the first
                       point of ambiguity, and the result is supplied
                       as new-string.

                       A directory name was completed.  Completion
                       was not successful because additional
                       components to the right of this directory
                       remain to be specified.  The string is
                       completed through the directory name and the
                       delimiter that follows it, and the result is
                       returned in new-string.

   The semantics of COMPLETE are not documented here.  See the
   "Reference Guide to Streams, Files, and I/O" in the Symbolics
   documentation set for the recommended semantics of COMPLETE.

8.5  CONTINUE Command

   Command:  (CONTINUE tid handle)

   Response: (CONTINUE tid)

   CONTINUE resumes a data transfer that was temporarily suspended due
   to an asynchronous error.  Each asynchronous error description has an
   optional argument of RESTARTABLE, indicating whether it makes any
   sense to try to continue after this particular error occurred.
   CONTINUE tries to resume the data transfer if the error is
   potentially recoverable, according to the RESTARTABLE argument in the
   asynchronous error description.  For a discussion of asynchronous
   errors:  See the section "NFILE Errors and Notifications", section
   10.

   handle is a required string-type argument that refers to the handle
   of the data channel that received an asynchronous error.  That data
   channel could have been in use for a data stream or direct access
   transfer.  handle cannot be a direct file identifier.

   If the asynchronous error description does not contain the
   RESTARTABLE argument, and the user issues the CONTINUE command
   anyway, the server gives a command error response.




Greenberg & Keene                                              [Page 20]

RFC 1037             NFILE - A File Access Protocol        December 1987


8.6  CREATE-DIRECTORY Command

   Command:  (CREATE-DIRECTORY tid pathname property-pairs)

   Response: (CREATE-DIRECTORY tid dir-truename)

   CREATE-DIRECTORY creates a directory on the remote file system.  The
   required pathname argument is a string identifying the pathname of
   the directory to be created.  The return value dir-truename is the
   pathname of the directory that was successfully created.  Both of
   these pathnames are directory pathnames:  See the section "Syntax of
   File and Directory Pathname Arguments", section 7.4.

   property-pairs is a keyword/value list of properties that further
   define the attributes of the directory to be created.  The allowable
   keywords and associated values are operating system dependent;
   typically they indicate arguments to be given to the native primitive
   for creating directories.

   If property-pairs is supplied as the empty token list, default access
   and creation attributes apply and should be assured by the server.
   See the section "Format of NFILE File Property/Value Pairs", section
   7.5.

8.7  CREATE-LINK Command

   Command:  (CREATE-LINK tid pathname target-pathname properties)

   Response: (CREATE-LINK tid link-truename)

   CREATE-LINK creates a link on the remote file system.

   pathname is the pathname of the link to be created; target-pathname
   is the place in the file system to which the link points.  Both are
   required arguments.  The return value link-truename names the
   resulting link.

   If a server on a file system that does not support links receives the
   CREATE-LINK command, it sends a command error response.

   The arguments pathname and target-pathname, and the return value
   link-truename, are all strings in the full pathname syntax of the
   server host.  See the section "Syntax of File and Directory Pathname
   Arguments", section 7.4.

   The required properties argument is a token list of keyword/value
   pairs. These properties and their values specify certain attributes
   to be given to the link.  The allowable keywords and associated



Greenberg & Keene                                              [Page 21]

RFC 1037             NFILE - A File Access Protocol        December 1987


   values are operating system dependent; typically they indicate
   arguments to be given to the native primitive for creating links.

   If no property pairs are given in the command, the server should
   apply a reasonable default set of attributes to the link.  See the
   section "Format of NFILE File Property/Value Pairs", section 7.5.

8.8  DATA-CONNECTION Command

   Command:  (DATA-CONNECTION tid new-input-handle new-output-handle)

   Response: (DATA-CONNECTION tid connection-identifier)

   DATA-CONNECTION enablesthe user side to initiate the establishment of
   a new data connection.  The user side supplies two required string
   arguments, new-input-handle and  new-output-handle.  These arguments
   are used by subsequent commands to reference the two data channels
   that constitute the data connection now being created.  new-input-
   handle describes the server-to-user data channel, and new-output-
   handle describes the user-to-server channel.  new-input-handle and
   new-output-handle cannot refer to any data channels already in use.

   Upon receiving the DATA-CONNECTION command, the server arranges for a
   logical port (called socket or contact name on some networks) to be
   made available on the foreign host machine.  When the server has made
   that port available, it must inform the user of its identity.  The
   server relays that information in the command response, in the
   required connection-identifier, a string.  The server then listens on
   the port named by connection-identifier, and waits for the user side
   to connect to it.

   Upon receiving the success command response, the user side supplies
   the connection-identifier to the local network implementation, in
   order to connect to the specified port.  The data connection is not
   fully established until the user side connects successfully to that
   port.  This command is unusual in that the successful command
   response does not signify the completion of the command; it indicates
   only that the server has fulfilled its responsibility in the process
   of establishing a data connection.