rfc1037.txt

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Greenberg & Keene                                              [Page 11]

RFC 1037             NFILE - A File Access Protocol        December 1987


    If you supply a handle and no pathname, the command format is:

         (DELETE tid handle)

    If you supply a pathname and no handle, the command format is:

         (DELETE tid empty-token-list pathname)

   The empty token list in the token list stream appears as a LIST-BEGIN
   followed immediately by a LIST-END.

   OPTIONAL KEYWORD/VALUE PAIRS

   Four NFILE commands have "optional keyword/value pairs".  These
   commands are: COMPLETE, LOGIN, OPEN, and READ.  Optional
   keyword/value pairs can be either included in the command or omitted
   entirely.  There is no need to substitute the empty token list for
   ommitted optional keyword tokens, unlike optional arguments.  The
   order of the option keyword/value pairs is not significant.

   If included, optional keyword/value pairs are a sequence of
   alternating keywords and values.  The values associated with the
   keywords can be keywords, lists, strings, Booleans, integers, dates,
   date-or-never's, and time intervals.  The text of each command
   description states what type of value is appropriate for each
   optional keyword.

   Optional keyword/value pairs appear in the text as the keyword only,
   in uppercase letters.  For example, here is the format of the LOGIN
   command:

   Command Format:

         (LOGIN tid user password FILE-SYSTEM USER-VERSION)

   FILE-SYSTEM and USER-VERSION are two optional keywords associated
   with the LOGIN command.  The user side can supply USER-VERSION, and
   omit FILE-SYSTEM as shown in this example:

         (LOGIN x105 tjones let-me-in USER-VERSION 2)

   As seen above, the optional keyword/value pair USER-VERSION, if
   supplied in a command, consists of the keyword USER-VERSION followed
   by the value to be used for that keyword (in this example, 2).







Greenberg & Keene                                              [Page 12]

RFC 1037             NFILE - A File Access Protocol        December 1987


7.3  Data Channel Handles and Direct File Identifiers

   Several NFILE commands require an argument that specifies an opening.
   This kind of argument is called a handle in the command description.
   It is always a string type argument.  A handle can be either a data
   channel handle or a direct file identifier, depending on the mode of
   the opening:


   Data Stream

   The handle must identify a data channel that is bound to an opening.

   Direct Access

   In general, the handle must be a direct file identifier.  A direct
   file identifier specifies a direct access opening.  It is the same as
   the value supplied in the DIRECT-FILE-ID keyword/value pair in the
   OPEN command.  It is used for all operations that identify an opening
   rather than a data channel.

   Two NFILE commands applicable to direct access openings are
   exceptions to the general rule.  The handle supplied in ABORT and
   CONTINUE cannot be a direct file identifier, but must be a data
   channel handle instead.

7.4  Syntax of File and Directory Pathname Arguments

   Some arguments and return values in the NFILE command descriptions
   represent file pathnames.  These are strings in the pathname syntax
   native to the server host.  These pathnames contain no host
   identifiers of any kind.  These pathnames must be fully defaulted, in
   the sense that they have a directory and file name (and file type, if
   the server operating system supports file types).  If appropriate, a
   device is referenced in the pathname.  If the server file system
   supports version numbers, there is always an explicit version number,
   even if that number or other specification is that system's
   representation of "newest" or "oldest".













Greenberg & Keene                                              [Page 13]

RFC 1037             NFILE - A File Access Protocol        December 1987


   Here are some examples of file pathnames, for different server hosts:

   Server Host     Example of File Pathname

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

      UNIX            /usr/max/life.c

      TOPS-20         ps:<max>life.bin.17

      VMS             MACD:[MAX]LIFE.FOR;3

      Symbolics LMFS  >max>life.lisp.newest

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

   The CREATE-DIRECTORY and HOME-DIRECTORY commands take a directory as
   an argument.  In NFILE commands, a directory is represented by a
   string that names the directory.  In most cases this string is in the
   syntax native to the server host.  However in some cases the native
   format is modified somewhat to clarify that the string names a
   directory, and not a file.  For example, a directory on UNIX is
   represented by "/usr/max/", not "/usr/max".

   Here are some examples of directory pathnames for different server
   hosts:

   Server Host     Example of Directory Pathname

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

      UNIX            /usr/max/

      TOPS-20         <max>

      VMS             MACD:[MAX]

      Symbolics LMFS  >max>hacks>

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

7.5  Format of NFILE File Property/Value Pairs

   Several NFILE commands request information regarding the properties
   of files or directories.  These commands include:  DIRECTORY,
   MULTIPLE-FILE-PLISTS, PROPERTIES, and CHANGE-PROPERTIES.  This
   section describes how file property information is conveyed over the
   token list stream.



Greenberg & Keene                                              [Page 14]

RFC 1037             NFILE - A File Access Protocol        December 1987


   File property information is usually sent in property/value pairs,
   where the property identifies the property, and the following value
   gives the value of that property for the specified file.

   Each property is denoted either by a keyword or an integer.  You can
   mix both ways of specifying properties (keyword or integer) within a
   single description.  An integer is interpreted as an index into the
   Property Index Table, an array of property keywords.  The server can
   optionally send a Property Index Table to the user during the
   execution of the LOGIN command, although it is not required.  This
   greatly reduces the length of transmissions.

   In command arguments, file properties cannot be specified with
   integers; keywords must be used to specify file properties in command
   arguments.  Integers can be used to denote file properties only in
   command responses.

   We now list the keywords associated with file properties.  This list
   is not intended to be restrictive.  If a programmer implementing
   NFILE needs a new keyword, a new keyword (not on this list) can be
   invented.  The type of value of any new keywords is by default
   string.  The keywords are sorted here by conceptual data type:

    Data type       Keywords denoting file properties

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

    Integers        BLOCK-SIZE, BYTE-SIZE, GENERATION-RETENTION-COUNT,
                    LENGTH-IN-BLOCKS, LENGTH-IN-BYTES,
                    DEFAULT-GENERATION-RETENTION-COUNT

    Dates           CREATION-DATE, MODIFICATION-DATE

    Date-or-never's REFERENCE-DATE, INCREMENTAL-DUMP-DATE,
                    COMPLETE-DUMP-DATE, DATE-LAST-EXPUNGED,
                    EXPIRATION-DATE

    Time intervals  AUTO-EXPUNGE-INTERVAL

    Keyword Lists   SETTABLE-PROPERTIES, LINK-TRANSPARENCIES,
                    DEFAULT-LINK-TRANSPARENCIES

    Boolean values  DELETED, DONT-DELETE, DONT-DUMP, DONT-REAP,
                    SUPERSEDE-PROTECT, NOT-BACKED-UP, OFFLINE,
                    TEMPORARY, CHARACTERS, DIRECTORY






Greenberg & Keene                                              [Page 15]

RFC 1037             NFILE - A File Access Protocol        December 1987


    Strings         ACCOUNT, AUTHOR, LINK-TO, PHYSICAL-VOLUME,
                    PROTECTION, VOLUME-NAME, PACK-NUMBER, READER,
                    DISK-SPACE-DESCRIPTION, and any keywords not
                    on this list

   Note that these keyword names are intended to imply the semantics of
   the properties.  For a discussion of the semantics of CREATION-DATE:
   See the section "NFILE OPEN Response Return Values", section 8.20.2.
   The "Reference Guide to Streams, Files, and I/O" in the Symbolics
   documentation set details the semantics that Symbolics associates
   with these properties.

8.  NFILE COMMANDS

   It is important to understand the conventions used in each of the
   following command descriptions.  See the section "Conventions Used in
   This Document", section 7.

8.1  ABORT Command

   Command:  (ABORT tid input-handle)

   Response: (ABORT tid)

   ABORT cleanly interrupts and prematurely terminates a single direct
   access mode data transfer initiated with READ.  The required input-
   handle string argument identifies a data channel on which an input
   transfer is currently taking place; this must be a direct access
   transfer.  input-handle must identify a data channel; it cannot be a
   direct file identifier.

   Upon receiving the ABORT command, the server checks to see if a
   transfer is still active on that channel.  If so, the server
   terminates the transfer by telling the data connection logical
   process to stop transferring bytes of data.  The user side needs to
   issue this command only when there are outstanding unread bytes.
   This excludes the case of the data channel having been disestablished
   or reallocated by the user side.

   Whether or not a transfer is active on that channel, the user side
   puts the data channel into the unsafe state.  Before the data channel
   can be used again, it must be resynchronized.

8.2  CHANGE-PROPERTIES Command

   Command:  (CHANGE-PROPERTIES tid handle pathname property-pairs)

   Response: (CHANGE-PROPERTIES tid)



Greenberg & Keene                                              [Page 16]

RFC 1037             NFILE - A File Access Protocol        December 1987


   CHANGE-PROPERTIES changes one or more properties of a file.  Either a
   handle or a pathname must be given, but not both.  Whichever one is
   given must be supplied as a string.  handle identifies a data channel
   that is bound to an open file; it can be a direct file identifier.
   pathname identifies a file on the server machine.

   property-pairs is a required token list of keyword/value pairs, where
   the name of the property to be changed is the keyword, and the
   desired new property value is the value.

   The properties that can be changed are host-dependent, as are any
   restrictions on the values of those properties.  The properties that
   can be changed are the same as those returned as settable-properties,
   in the command response for the PROPERTIES command.

   The server tries to modify all the properties listed in property-
   pairs to the desired new values.  There is currently no definition
   about what should be done if the server can successfully change some
   properties but not others.