Proposed Network Standard Data Pathname syntax
RFC 615

Document Type RFC - Unknown (March 1974; No errata)
Obsoleted by RFC 645
Last updated 2013-03-02
Stream Legacy
Formats plain text html pdf htmlized bibtex
Stream Legacy state (None)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state RFC 615 (Unknown)
Telechat date
Responsible AD (None)
Send notices to (None)
Network Working Group                                     D. Crocker (UCLA-NMC)
Request for Comments: 615                                                MAR 74
NIC #21531

                           Proposed Network
                     Standard Data Pathname Syntax

There seems to be an increasing call for a Network Standard Data Pathname
(NSDP); that is, a standardized means of referring to a specific location
for/of a collection of bits somewhere on the Network.

The reasons for a standard or virtual anything have been discussed, at
length, elsewhere and will not be elaborated upon here. Rather than
attack the entire issue of virtual pathnames, I wish only to propose a
standardized SYNTAX for specifying pathnames. Such a standard will be
useful for 1) users who are unfamiliar with a site or who use several
different sites and do not want to have to remember each site's
idiosynchracies, 2) programs accessing data at several other sites, and
3) documentation:

The syntax allows the user to specify the necessary network, host,
peripheral device, directory, file, type, and site-specific fields.
Adding other fields, as needed, is expected to be quite simple.

First the BNF:

   <NSDP> ::= % <bulk> <cr><lf>
   <bulk> ::= <field> / <field> <bulk>

   <field> ::= <key> <L-delim> <name> <R-delim>

             FILE / TYPE / SITEPARM / N / H / P / D / F /
             T / S

<L-delim> ::= any printable character that is not in the
              succeeding <name> field and that is
              acceptable to the object site: For visual
              aesthetics and to facilitate human parsing,
              anytime <L-delim> is a left-bracket
              character (<, [, (, _), <R-delim> must be
              the complementary right-bracket character
              (>, ], ), |).

<name> ::=    any sequence of characters acceptable to the
              object site. This is the actual data field
              with the file, directory, device (or
              whatever) name.

<R-delim> ::= Either 1) the same character as <L-delim> or
              2) if the <L-delim> character is a
              left-bracket character (<, [, (, _) then its
              complementary right-bracket (>, ], ), |).


<cr> ::=      carriage-return

<lf> ::=      line-feed

And some elaboration:

The syntax allows <name> fields to be an arbitrary number of rs long.
Case is irrelevant to the syntax, though some sites will care about case
in <name> fields:

<Key> indicates what part of the pathname the next <name> is going to
refer to: The single-character keys are abbreviations for the respective
full-word keys:

<Fields> ARE order dependent, but defaulted ones may be omitted. The
order is as indicated for <key>s: That is, Network, Host, ..: Siteparm:

Fields may be repeated, as appropriate for the object site; that is,
multiple Directory fields, etc:

The validity of any combination of <field>s is entirely site-dependent:
For example, if a site will accept it, an NSDP with a Host field, and
nothing more, is permissible:

<delim> is used to delimit the beginning and end of the <name> field:

Explanation of <key>s:

       NETWORK or N:   Currently, only ARPA is defined.

       HOST or H:      Reference to host, by official name or
                       nickname or number: The default radix is
                       ten; a numeric string ending with "H"
                       indicates hexadecimal, "O"(oh) indicates
                       octal, and (gratuitously) "D" indicates

      PERIPHERAL or P: Peripheral device being referred to:

      DIRECTORY or D:  Name of a directory which contains a
                       pointer to the entity (directory or
                       filename) specified in the following

      FILE or F:       Basic name of the file or data set:

      TYPE or T:       Optional modifier to filename: (Tenex
                       calls it the extension.)

      SITEPARM or S:   A parameter, such as an access
                       specification or version number, peculiar
                       to the object site. The content of the
                       <name> field must serve to identify what
                       Siteparm is involved. Each site will be
                       responsible for defining the syntax of
                       Siteparm <name>s it will accept.


Some reserved PERIPHERAL <name>s:

      DISK or DSK:     Immediately accessible, direct-access

      ONLINE or ONL:    Whatever immediately-accessible (measured
                        in fractions of a second) storage the
                        user accesses by default; usually disk:

      TAPE or TAP:      Industry-compatible magnetic tape:

      TAPE7 or TP7:     7-Track industry compatible tape:

      TAPE9 or TP9:     9-Track industry compatible tape:
Show full document text