draft-ietf-nntpext-base-10.txt   draft-ietf-nntpext-base-11.txt 
INTERNET DRAFT S. Barber INTERNET DRAFT S. Barber
Expires: January 15, 2001 Academ Consulting Services Expires: May 30, 2001 Academ Consulting Services
July 2000 October 2000
Network News Transport Protocol Network News Transport Protocol
draft-ietf-nntpext-base-11.txt
draft-ietf-nntpext-base-10.txt
1. Status of this Document 1. Status of this Document
This document is an Internet-Draft and is in full conformance This document is an Internet-Draft and is in full conformance
with Section 10 of RFC 2026. Internet-Drafts are working with Section 10 of RFC 2026. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its documents of the Internet Engineering Task Force (IETF), its
areas, and its working groups. Note that other groups may areas, and its working groups. Note that other groups may
also distribute working documents as Internet-Drafts. also distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or made obsolete by other months and may be updated, replaced, or made obsolete by other
documents at any time. It is inappropriate to use Internet- documents at any time. It is inappropriate to use Internet-
Drafts as reference material or to cite them other than as Drafts as reference material or to cite them other than as
"work in progress." "work in progress."
The list of current Internet-Drafts can be accesses at The list of current Internet-Drafts can be accesses at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft shadow directories can be accessed The list of Internet-Draft shadow directories can be accessed
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at http://www.ietf.org/shadow.html. at http://www.ietf.org/shadow.html.
This section will be updated with the appropriate verbiage This section will be updated with the appropriate verbiage
from RFC 2223 should this document has been found ready for from RFC 2223 should this document has been found ready for
publication as an RFC. publication as an RFC.
This document is a product of the NNTP Working Group, chaired This document is a product of the NNTP Working Group, chaired
by Ned Freed and Stan Barber. by Ned Freed and Stan Barber.
2. Abstract 2. Abstract
The Network News Transport Protocol has been in use in the The Network News Transport Protocol has been in use in the
Internet for a decade and remains one of the most popular Internet for a decade and remains one of the most popular
protocols (by volume) in use today. This document is a protocols (by volume) in use today. This document is a
replacement for RFC 977 and officially updates the protocol replacement for RFC 977 and officially updates the protocol
specification. It clarifies some vagueness in RFC 977, specification. It clarifies some vagueness in RFC 977,
includes some new base functionality and provides a specific includes some new base functionality and provides a specific
mechanism to add standardized extensions to NNTP. mechanism to add standardized extensions to NNTP.
3. Introduction 3. Introduction
This document specifies the Network News Transport Protocol This document specifies the Network News Transport Protocol
(NNTP), which is used for the distribution, inquiry, (NNTP), which is used for the distribution, inquiry,
retrieval, and posting of net news articles using a reliable retrieval, and posting of net news articles using a reliable
stream-based mechanism. For news reading clients, NNTP enables stream-based mechanism. For news reading clients, NNTP enables
retrieval of news articles that are stored in a central retrieval of news articles that are stored in a central
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October 2000
database, giving subscribers the ability to select only those database, giving subscribers the ability to select only those
articles they wish to read. articles they wish to read.
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The netnews model provides for indexing, cross-referencing, The netnews model provides for indexing, cross-referencing,
and expiration of aged messages. For server-to-server and expiration of aged messages. For server-to-server
interaction, NNTP is designed for efficient transmission of interaction, NNTP is designed for efficient transmission of
net news articles over a reliable full duplex communication net news articles over a reliable full duplex communication
method. method.
Every attempt is made to insure that the protocol Every attempt is made to insure that the protocol
specification in this document is compatible with the version specification in this document is compatible with the version
specified in RFC 977[1]. However, this version does not specified in RFC 977[1]. However, this version does not
support the ill-defined SLAVE command and permits four digit support the ill-defined SLAVE command and permits four digit
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"conditionally compliant". "conditionally compliant".
For the remainder of this memo, the term "client host" refers For the remainder of this memo, the term "client host" refers
to a host making use of the NNTP service, while the term to a host making use of the NNTP service, while the term
"server host" refers to a host that offers the NNTP service. "server host" refers to a host that offers the NNTP service.
In addition, where examples of interactions between a client In addition, where examples of interactions between a client
host and a server host are provided a "[C]" will be used to host and a server host are provided a "[C]" will be used to
represent the client host and a "[S]" will be used to represent the client host and a "[S]" will be used to
represent the server host. represent the server host.
4. Basic Operation. 4. Basic Operation
Every NNTP session MUST involve the following in this order: Every NNTP session MUST involve the following in this order:
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CONNECTION CONNECTION
GREETING GREETING
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DISCONNECTION DISCONNECTION
Other steps may occur between the GREETING and DISCONNECTION Other steps may occur between the GREETING and DISCONNECTION
step. They are: step. They are:
CAPABILITIES DISCOVERY CAPABILITIES DISCOVERY
NEWS EXCHANGE NEWS EXCHANGE
CONCLUSION CONCLUSION
NNTP operates over any reliable data stream 8-bit-wide NNTP operates over any reliable data stream 8-bit-wide
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The character set for all NNTP commands is UTF-8. Commands in The character set for all NNTP commands is UTF-8. Commands in
the NNTP MUST consist of an US-ASCII case-insensitive keyword, the NNTP MUST consist of an US-ASCII case-insensitive keyword,
which MAY be followed by one or more arguments. An US-ASCII which MAY be followed by one or more arguments. An US-ASCII
CRLF pair MUST terminate all commands. Multiple commands MUST CRLF pair MUST terminate all commands. Multiple commands MUST
NOT be on the same line. Keywords MUST consist of printable NOT be on the same line. Keywords MUST consist of printable
US-ASCII characters. Unless otherwise noted elsewhere in this US-ASCII characters. Unless otherwise noted elsewhere in this
document, arguments SHOULD consist of printable US-ASCII document, arguments SHOULD consist of printable US-ASCII
characters. Keywords and arguments MUST be each separated by characters. Keywords and arguments MUST be each separated by
one or more US-ASCII SPACE or US-ASCII TAB characters. one or more US-ASCII SPACE or US-ASCII TAB characters.
Keywords MUST be at least three US-ASCII characters and MUST Keywords MUST be at least three US-ASCII characters and MUST
NOT exceed 12 US-ASCII characters. Command lines MUST NOT NOT exceed 12 US-ASCII characters. Command lines MUST NOT
exceed 512 octets, which includes the terminating US-ASCII exceed 512 octets, which includes the terminating US-ASCII
CRLF pair. Arguments MUST NOT exceed 497 octets. CRLF pair. Arguments MUST NOT exceed 497 octets.
Each response MUST start with a three-digit response code that Each response MUST start with a three-digit response code that
is sufficient to distinguish all responses. Unless is sufficient to distinguish all responses. Certain valid
specifically specified as one of the valid responses for a responses are defined to be multi-line; for all others, the
command (such as those described later in this document), each response is contained in a single line. All multi-line
response is contained in a single line. However, certain
responses from commands may be multi-line. All multi-line Barber [Page 3]
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responses MUST adhere to the following format: After sending responses MUST adhere to the following format: After sending
the first line of the response and an US-ASCII CRLF, any the first line of the response and an US-ASCII CRLF, any
additional lines are sent, each terminated by an US-ASCII CRLF additional lines are sent, each terminated by an US-ASCII CRLF
pair. When all lines of the response have been sent, a final pair. When all lines of the response have been sent, a final
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line MUST be sent, consisting of a termination octet (US-ASCII line MUST be sent, consisting of a termination octet (US-ASCII
decimal code 046, ".") and an US-ASCII CRLF pair. If any line decimal code 046, ".") and an US-ASCII CRLF pair. If any line
of the multi-line response begins with the termination octet, of the multi-line response begins with the termination octet,
the line MUST be "byte-stuffed" by pre-pending the termination the line MUST be "byte-stuffed" by pre-pending the termination
octet to that line of the response. Hence, a multi-line octet to that line of the response. Hence, a multi-line
response is terminated with the five octets "CRLF.CRLF" (in response is terminated with the five octets "CRLF.CRLF" (in
US-ASCII). When examining a multi-line response, the client US-ASCII). When examining a multi-line response, the client
MUST check to see if the line begins with the termination MUST check to see if the line begins with the termination
octet. If so and if octets other than US-ASCII CRLF follow, octet. If so and if octets other than US-ASCII CRLF follow,
the first octet of the line (the termination octet) MUST be the first octet of the line (the termination octet) MUST be
stripped away. If so and if US-ASCII CRLF immediately follows stripped away. If so and if US-ASCII CRLF immediately follows
the termination character, then the response from the NNTP the termination character, then the response from the NNTP
server is ended and the line containing ".CRLF" (in US-ASCII) server is ended and the line containing ".CRLF" (in US-ASCII)
MUST NOT considered part of the multi-line response. The MUST NOT considered part of the multi-line response. Where a
keywords that support multi-line responses have the format of response is multi-line, the description of the command will
those responses described in the responses section. define the format of the response before "byte-stuffing" takes
place.
A NNTP server MAY have an inactivity autologout timer. Such a A NNTP server MAY have an inactivity autologout timer. Such a
timer MUST be of at least three minutes duration. The receipt timer MUST be of at least three minutes duration. The receipt
of any command from the client during that interval SHOULD of any command from the client during that interval SHOULD
suffice to reset the autologout timer. When the timer suffice to reset the autologout timer. When the timer
expires, the server should close the TCP connection without expires, the server should close the TCP connection without
sending any response to the client. sending any response to the client.
4.1 Response Codes 4.1 Response Codes
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The first digit of the response broadly indicates the success, The first digit of the response broadly indicates the success,
failure, or progress of the previous command. failure, or progress of the previous command.
1xx - Informative message 1xx - Informative message
2xx - Command ok 2xx - Command ok
3xx - Command ok so far, send the rest of it. 3xx - Command ok so far, send the rest of it.
4xx - Command was correct, but couldn't be performed for some 4xx - Command was correct, but couldn't be performed for some
reason. reason.
5xx - Command unimplemented, or incorrect, or a serious 5xx - Command unimplemented, or incorrect, or a serious
program error occurred. program error occurred.
The next digit in the code indicates the function response The next digit in the code indicates the function response
category. category.
x0x - Connection, setup, and miscellaneous messages x0x - Connection, setup, and miscellaneous messages
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x1x - Newsgroup selection x1x - Newsgroup selection
x2x - Article selection x2x - Article selection
x3x - Distribution functions x3x - Distribution functions
x4x - Posting x4x - Posting
x8x - Nonstandard (private implementation) extensions x8x - Reserved for authentication and authorization extensions
x9x - Debugging output x9x - Reserved for private use (non-standard extensions)
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The exact response codes that can be returned in response to a
given command are detailed in the description of the keyword
that is the first part of the command. In addition, there is a
debugging set of response codes that MAY be received at any
time. These are described later in this section.
Certain response codes contain parameters such as numbers and Certain responses contain parameters such as numbers and names
names in addition to the status indicator. In those cases, the in addition to the status indicator. In those cases, the
number and type of such parameters MUST be fixed for each number and type of such parameters is fixed for each response
response code to simplify interpretation of the response. In code to simplify interpretation by the client (any extension
all other cases, the client MUST only use the status indicator MUST follow this principle as well). In all other cases, the
itself to determine the nature of the response. client MUST only use the status indicator itself to determine
the nature of the response. The exact response codes that can
be returned in response to a given command are detailed in the
description of the keyword that is the first part of the
command.
Parameters MUST be separated from the numeric status indicator Parameters MUST be separated from the numeric status indicator
and from each other by a single US-ASCII space. All numeric and from each other by a single US-ASCII space. All numeric
parameters MUST be in base 10 (decimal) format, and MAY have parameters MUST be in base 10 (decimal) format, and MAY have
leading zeros. All string parameters MUST begin after the leading zeros. String parameters MUST contain at least one
separating space, and MUST end before the following separating character and MUST NOT contain US-ASCII spaces, CR, LF, or
space or the US-ASCII CRLF pair at the end of the line. tab). The server MAY add any text after the response code or
(Therefore, string parameters MUST NOT contain US-ASCII last parameter as appropriate, and the client MUST NOT make
spaces.) All text, if any, in the response which is not a decisions based on this text. Such text MUST be separated from
parameter of the response must follow and be separated from the numeric status indicator or the last parameter by at least
the last parameter by an US-ASCII space. Also, note that the one US-ASCII space.
text following a response number may vary in different
implementations of the server. The 3-digit numeric status
indicator should be used to determine what response was sent.
Response codes not specified in this standard MAY be used for A server MUST respond to an unrecognized, unimplemented, or
any installation-specific additional commands also not invalid command with a negative response code as follows. An
specified. These SHOULD be chosen to fit the pattern of x8x unrecognized command, or an optional command or extension that
specified above. (Note that debugging is provided for is not implemented by the server, MUST be given a 500
explicitly in the x9x response codes.) response. A syntax error in a recognized command MUST be given
a 501 response. A command that is valid but not permitted
because of the current internal state of the server MUST be
given a 4XX or 5XX response.
The use of unspecified response codes for a standard command Each recognized command MUST return 501 (as above) or one of
is prohibited. the response codes specifically listed in its description or
in an extension. A server MAY provide extensions to this
specification, including new commands, new features of
existing commands, and other ways of changing the internal
state of the server. However, the server MUST NOT produce any
other responses to a client that does not invoke any of the
additional features. (Therefore a client that restricts itself
to this specification will only receive the responses that are
listed).
The status indicator pattern x9x is provided for debugging. Barber [Page 5]
Since much debugging output may be classed as "informative
messages", it MUST be the case that responses 190 through 199
WILL be used for various debugging outputs. There is no
requirement in this specification for debugging output.
However, if such is provided over the connected stream, it
MUST use these response codes. If appropriate to a specific
implementation, other x9x codes MAY be used for debugging.
(For example, response code 290 could be used to acknowledge a
remote debugging request.) By default, a server implementation
MUST NOT send debugging responses. Such behavior MUST only
occur when specifically activated. See section XX for
information on the DEBUG command.
A server MUST respond to an unrecognized, unimplemented, or INTERNET DRAFT S. Barber
syntactically invalid command with a negative response code Expires: May 30, 2001 Academ Consulting Services
(status indicators of the form 5XX). For unrecognized October 2000
commands, the 500 response code MUST be returned. This
Barber [Page 5] If a client receives an unexpected response, it SHOULD use the
includes servers that have not implemented the optional first digit of the response to determine the result. For
extensions outlined later in this memo. For recognized example, an unexpected 2xx should be taken as success and an
commands where the syntax is wrong, the 501 response code MUST unexpected 4xx or 5xx as failure.
be returned. A server MUST respond to a command issued when
the session is in an incorrect state by responding with a Response codes not specified in this standard MAY be used for
negative status indicator. This may be from either the 4XX or any installation-specific additional commands also not
5XX group as appropriate. specified. These SHOULD be chosen to fit the pattern of x9x
specified above.
Neither this document nor any extension registered with IANA
(see section 12) will specify any response codes of the x9x
pattern. (Implementers of extensions are accordingly cautioned
not to use such responses for extensions that may subsequently
be submitted for registration.)
5. The WILDMAT format 5. The WILDMAT format
The WILDMAT format[5] described here is based on the version The WILDMAT format[5] described here is based on the version
first developed by Rich Salz which was derived from the format first developed by Rich Salz which was derived from the format
used in the UNIX "find" command to articulate file names. It used in the UNIX "find" command to articulate file names. It
was developed to provide a uniform mechanism for matching was developed to provide a uniform mechanism for matching
patterns in the same manner that the UNIX shell matches patterns in the same manner that the UNIX shell matches
filenames. Patterns are implicitly anchored at the beginning filenames. Patterns are implicitly anchored at the beginning
and end of each string when testing for a match. There are and end of each string when testing for a match. There are
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the same as the logical not of the third operation and is the same as the logical not of the third operation and is
specified the same way as the third with the addition of a specified the same way as the third with the addition of a
caret character (^) at the beginning of the test string just caret character (^) at the beginning of the test string just
inside the open square bracket. The final operation uses the inside the open square bracket. The final operation uses the
backslash character to invalidate the special meaning of the backslash character to invalidate the special meaning of the
open square bracket ([), the asterisk, backslash, or the open square bracket ([), the asterisk, backslash, or the
question mark. Two backslashes in sequence will result in the question mark. Two backslashes in sequence will result in the
evaluation of the backslash as a character with no special evaluation of the backslash as a character with no special
meaning. meaning.
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Implementers must be careful to apply the pattern-matching Implementers must be careful to apply the pattern-matching
operators to whole characters encoded in UTF-8, and not two operators to whole characters encoded in UTF-8, and not two
individual octets. individual octets.
5.1 Negating the wildmat pattern 5.1 Negating the wildmat pattern
The exclamation point can be used at the beginning of a wildmat The exclamation point can be used at the beginning of a wildmat
to negate it. That is, if the remainder of the pattern would to negate it. That is, if the remainder of the pattern would
match the string then the negated pattern does not, and vice match the string then the negated pattern does not, and vice
versa. If it appears as any other character other than the first versa. If it appears as any other character other than the first
one, it has no special meaning. one, it has no special meaning.
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5.2 Examples 5.2 Examples
a) [^]-] -- matches any single character other than a a) [^]-] -- matches any single character other than a
close square bracket or a minus sign/dash. close square bracket or a minus sign/dash.
b) *bdc -- matches any string that ends with the string b) *bdc -- matches any string that ends with the string
"bdc" including the string "bdc" (without quotes). "bdc" including the string "bdc" (without quotes).
c) [0-9a-zA-Z] -- matches any single printable c) [0-9a-zA-Z] -- matches any single printable
alphanumeric ASCII character. alphanumeric ASCII character.
d) a??d -- matches any four character string which d) a??d -- matches any four character string which
begins with a and ends with d. begins with a and ends with d.
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6. Format for Keyword Descriptions 6. Format for Keyword Descriptions
On the following pages are descriptions of each keyword On the following pages are descriptions of each keyword
recognized by the NNTP server and the responses that will be recognized by the NNTP server and the responses that will be
returned by those commands. These keywords are grouped by the returned by those commands. These keywords are grouped by the
functional step in which they are used. functional step in which they are used.
Each keyword is shown in upper case for clarity, although the Each keyword is shown in upper case for clarity, although the
NNTP server ignores case in the interpretation of commands. NNTP server ignores case in the interpretation of commands.
Any parameters are shown in lower case. A parameter shown in
[square brackets] is optional. For example,[wildmat] indicates
that a wildmat may be present or omitted. A parameter that may
be repeated is followed by an ellipsis. Mutually exclusive
parameters are separated by a vertical bar (|) character. For
example, ggg|<message-id> indicates that a group name or a
<message-id> may be specified, but not both. Unless stated
otherwise, a parameter name in lowercase represents a token
described elsewhere, while one in uppercase is a literal
string that is included as written. Some parameters may be
case or language specific. See RFC 1036[6] for these details.
In addition, certain commands make use of a pattern for Parameters are shown as follows:
selection of multiple news groups. The pattern in all cases is o UPPERCASE indicates literal text to be included in the
based on the WILDMAT format. Arguments expected to be in command;
wildmat format will be represented by the string wildmat. This o lowercase indicates a token described elsewhere;
format is discussed in detail in section 5 of this memo. o [brackets] indicate that the parameter is optional;
o ellipsis... indicates that the parameter may be repeated
any number of times (it must occur at least once);
o vertical|bar indicates a choice of two mutually exclusive
parameters (exactly one must be provided).
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Parameters are case or language specific only when specified
(either in this document or in RFC 1036[6]).
The name "wildmat" for a parameter indicates that it is a
wildmat format pattern as defined in section 5.
7. The GREETING Step 7. The GREETING Step
7.1 Initial Connection 7.1 Initial Connection
There is no keyword presented by the client upon initial There is no keyword presented by the client upon initial
connection to the server. The server MUST present an connection to the server. The server MUST present an
appropriate response code as a greeting to the client. This appropriate response code as a greeting to the client. This
response informs the client about what steps the client should response informs the client about what steps the client should
take to reach the news exchange step. take to reach the news exchange step.
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If the server will accept further commands from the client If the server will accept further commands from the client
including POST, the server MUST present a 200 greeting code. including POST, the server MUST present a 200 greeting code.
If the server will accept further commands from the client, If the server will accept further commands from the client,
but it is not authorized to post articles using the POST but it is not authorized to post articles using the POST
command, the server MUST present a 201 greeting code. command, the server MUST present a 201 greeting code.
Otherwise the server MUST present a 400 or 504 greeting code Otherwise the server MUST present a 400 or 502 greeting code
and then immediately close the connection. 504 MUST be used if and then immediately close the connection. 502 MUST be used if
the client is not permitted under any circumstances to the client is not permitted under any circumstances to
interact with the server and 400 otherwise. interact with the server and 400 otherwise.
7.1.1 Initial Connection Example 7.1.1 Initial Connection Example
Example of a normal connection from an authorized client Example of a normal connection from an authorized client
[C] Initial TCP connection completed [C] Initial TCP connection completed
[S] 200 NNTP Service Ready, posting permitted [S] 200 NNTP Service Ready, posting permitted
Client can send commands at this point. In this example, the Client can send commands at this point. In this example, the
client jumps directly to the conclusion step (See section client jumps directly to the conclusion step (See section 10).
10.1).
[C] QUIT [C] QUIT
[S] 205 NNTP Service exits normally [S] 205 NNTP Service exits normally
Example of a normal connection from an unauthorized client Example of a normal connection from an unauthorized client
[C] Initial TCP connection completed [C] Initial TCP connection completed
[S] 502 NNTP Service Unavailable
[S] 504 NNTP Service Unavailable
At this point, the server closes the TCP connection. At this point, the server closes the TCP connection.
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Example of a normal connection from an authorized client that Example of a normal connection from an authorized client that
is not permitted to post is not permitted to post
[C] Initial TCP connection completed [C] Initial TCP connection completed
[S] 201 NNTP Service Ready, posting prohibited [S] 201 NNTP Service Ready, posting prohibited
Client can send commands at this point. In this example, the Client can send commands at this point. In this example, the
client jumps directly to the conclusion step (See section client jumps directly to the conclusion step (See section 10).
10.1).
[C] QUIT [C] QUIT
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[S] 205 NNTP Service exits normally [S] 205 NNTP Service exits normally
Example of a connection from any client where the server is Example of a connection from any client where the server is
unable to provide service unable to provide service
[C] Initial TCP connection completed [C] Initial TCP connection completed
[S] 400 NNTP Service temporarily unavailable [S] 400 NNTP Service temporarily unavailable
At this point, the server closes the TCP connection. At this point, the server closes the TCP connection.
7.1.2 MODE READER 7.1.2 MODE READER
MODE READER MODE READER
MODE READER SHOULD be used by the client to indicate to the
MODE READER MAY be used by the client to indicate to the
server that it is a news reading client. This command may be server that it is a news reading client. This command may be
entered at any time. The server MUST present a greeting code entered at any time. The server MUST present a response (as
(as described in section 7.1.2.1) appropriate to the server's described in section 7.1) appropriate to the server's ability
ability to provide service to this client in this mode. to provide service to this client in this mode.
7.1.2.1 Responses 7.1.2.1 Responses
200 Hello, you can post
201 Hello, you can't post 200 Posting Permitted
201 Posting Not Permitted
400 Service temporarily unavailable 400 Service temporarily unavailable
502 Service unavailable 502 Service unavailable
Following a 400 or 502 response the server MUST immediately
close the connection.
Note that the response need not be the same as the one
presented during the initial greeting.
7.1.2.2 MODE READER Examples 7.1.2.2 MODE READER Examples
Example of use of the MODE READER command by an authorized Example of use of the MODE READER command by an authorized
client client
[C] MODE READER Barber [Page 9]
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[C] MODE READER
[S] 200 NNTP Service Ready, posting permitted [S] 200 NNTP Service Ready, posting permitted
Client can send commands at this point. In this example, the Client can send commands at this point. In this example, the
client jumps directly to the conclusion step (See section client jumps directly to the conclusion step (See section 10).
10.1).
[C] QUIT [C] QUIT
[S] 205 NNTP Service exits normally [S] 205 NNTP Service exits normally
Example of use of MODE READER by a client not authorized to Example of use of MODE READER by a client not authorized to
receive service from the server as a news reader receive service from the server as a news reader
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[C] MODE READER [C] MODE READER
[S] 502 Service Unavailable [S] 502 Service Unavailable
At this point, the server closes the TCP connection. At this point, the server closes the TCP connection.
Example of a normal connection from an authorized client that Example of a normal connection from an authorized client that
is not permitted to post is not permitted to post
[C] MODE READER [C] MODE READER
[S] 201 NNTP Service Ready, posting prohibited [S] 201 NNTP Service Ready, posting prohibited
Client can send commands at this point. In this example, the Client can send commands at this point. In this example, the
client jumps directly to the conclusion step (See section client jumps directly to the conclusion step (See section 10).
10.1).
[C] QUIT [C] QUIT
[S] 205 NNTP Service exits normally [S] 205 NNTP Service exits normally
Example of a connection from any client where the server is Example of a connection from any client where the server is
unable to provide news reader service unable to provide news reader service
[C] MODE READER [C] MODE READER
[S] 400 NNTP Service temporarily unavailable [S] 400 NNTP Service temporarily unavailable
At this point, the server closes the TCP connection. At this point, the server closes the TCP connection.
8. The CAPABILITIES DISCOVERY Step 8. The CAPABILITIES DISCOVERY Step
A client NNTP supporting NNTP service extensions should query An NNTP client that wishes to use extensions to NNTP can query
a server early in the session for extensions session by the server to determine which extensions are available. This
issuing the LIST EXTENSIONS command. If the NNTP server is done with the LIST EXTENSIONS command.
supports the NNTP service extensions it MUST give a successful
response (see section 8.1.1), a failure response (see section If a particular extension is unavailable, the client can
8.1.2), or an error response (see section 8.1.3). If the NNTP attempt to work around it or it may wish to terminate the
server does not support any NNTP service extensions, it MUST session.
generate an error response (see section 8.1.4).
Barber [Page 10]
INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
See section 12 for further discussion of extensions.
8.1 LIST EXTENSIONS 8.1 LIST EXTENSIONS
If successful, the server NNTP MUST respond with code 202. On The LIST EXTENSIONS command allows a client to determine which
failure, the server NNTP MUST respond with code 503. On error, extensions are supported by the server.
Barber [Page 10] A client NNTP supporting NNTP service extensions SHOULD query
the server NNTP MUST respond with one of codes 400, 402, 500, a server early in the session for extensions session by
501 and 502. issuing the LIST EXTENSIONS command. An NNTP Server that
conforms to the specification in this document MUST give a
successful response (see section 8.1.1), a failure response
(see section 8.1.2), or an error response (see section 8.1.3).
This command MAY be issued at anytime during a session. It is This command MAY be issued at anytime during a session. It is
not required that the client issues this command before not required that the client issues this command before
attempting to make use of any extension. The response attempting to make use of any extension. The response
generated by this command MAY change during a session because generated by this command MAY change during a session because
of other state information. However, a client NNTP MUST NOT of other state information. However, a client NNTP MUST NOT
cache (for use in another session) any information returned if cache (for use in another session) any information returned if
the LIST EXTENSIONS command succeeds. That is, a client NNTP the LIST EXTENSIONS command succeeds. That is, a client NNTP
is only able to get the current and correct information is only able to get the current and correct information
concerning available extensions during a session by issuing a concerning available extensions during a session by issuing a
LIST EXTENSIONS command during that session and processing LIST EXTENSIONS command during that session and processing
that response. that response.
8.1.1 Successful response 8.1.1 Successful response
If the server NNTP implements and is able to perform the LIST A successful response starts with a 202 code and is followed
EXTENSIONS command, it MUST return code 202. by a list of extension-labels, one per line. Each line MUST
begin with exactly one space followed by an extension-label
Text following the return code on the first line of the reply and optionally one or more parameters (separated by single
is free form, and not interpreted, and has no practical use, spaces). The extension-label and the meaning of the parameters
as this text is not expected to be revealed to end users. The are specified as part of the definition of the extension. The
syntax of other reply lines is precisely defined, and if extension-label MUST be in uppercase.
present, MUST be exactly as specified.
Each line listing an extension in the extension-listing begins
with a single space. That space IS NOT optional, nor does it
indicate general white space. This space guarantees that the
line can never be misinterpreted as the end of the extension-
listing, but is required even where there is no possibility of
ambiguity.
Each extension supported MUST be listed on a separate line to
facilitate the possible inclusion of parameters supported by
each extension command. The extension-label to be used in the
response to the LIST EXTENSIONS command will be specified as
each new extension is added to the NNTP command set. Often it
will be the name of a new command added; however this IS NOT
required. In fact, it IS NOT required that a new feature
actually adds a new command or keyword. Any parameters
included are to be specified with the definition of the
command concerned.
That specification SHALL also specify how any parameters
present are to be interpreted and how each parameter is
separated from other parameters.
The extension-label is nominally case insensitive, however the
definitions of specific labels and parameters specify the
precise interpretation, and it is to be expected that those
definitions will usually specify the label in a case
Barber [Page 11]
independent manner. Where this is done, implementations are
recommended to use US-ASCII upper case letters when
transmitting the extension response.
Except where stated otherwise, the commands in this document
are understood (even if not supported) by all servers and are
not described in the list of features returned by the LIST
EXTENSIONS command.
The server MUST NOT list the same extension twice in the
response, and MUST list all supported extensions. The order in
which the extensions are listed is not significant. The server
need not even consistently return the same order.
The end of the list is defined by the usual period on a line The end of the list is defined by the usual period on a line
by itself. by itself.
A typical example reply to the LIST EXTENSIONS command might A typical example reply to the LIST EXTENSIONS command might
be a multiline reply of the form: be a multiline reply of the form:
[C] LIST EXTENSIONS [C] LIST EXTENSIONS
[S] 202 Extensions supported: Barber [Page 11]
[S] OVER INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
[S] 202 Extensions supported:
[S] OVER
[S] PAT [S] PAT
[S] LISTGROUP [S] LISTGROUP
[S] . [S] .
The particular extensions shown here are simply examples of
what may be defined in other places, no particular meaning
should be attributed to them. Recall also, that the extension
names returned are not command names, as such, but simply
indications that the server possesses some attribute or other.
The order in which the extensions are returned is of no
importance, NNTP server processes are not required to
implement any particular order, or even to consistently return
the same order when the command is repeated.
8.1.2 Failure response 8.1.2 Failure response
If for some reason the server NNTP is unable to list the If for some reason the server NNTP is unable to list the
service extensions it supports, it MUST return code 503. No service extensions it supports, it MUST return code 503. No
list (not even an empty one) will be returned. list (not even an empty one) will be returned.
In the case of a failure response, the client NNTP may try the In the case of a failure response, the client NNTP may try the
extensions either as the need arises or configure itself for extensions either as the need arises or configure itself for
the basic NNTP functionality defined in this document. the basic NNTP functionality defined in this document.
Barber [Page 12]
8.1.3 Error responses from extended servers 8.1.3 Error responses from extended servers
If the server NNTP recognizes the LIST EXTENSIONS command, but If the server NNTP recognizes the LIST EXTENSIONS command, but
due to various conditions cannot make any extensions available due to various conditions cannot make any extensions available
to the client at the time the client issued the LIST to the client at the time the client issued the LIST
EXTENSIONS command, it MUST return code 402. No list (not even EXTENSIONS command, it MUST return code 402. No list (not even
an empty one) will be returned. an empty one) will be returned.
The client NNTP should configure itself for the basic NNTP The client NNTP should configure itself for the basic NNTP
functionality defined in this document, or issue commands that functionality defined in this document, or issue commands that
skipping to change at line 651 skipping to change at line 647
longer available (e.g., due to imminent system shutdown), it longer available (e.g., due to imminent system shutdown), it
must return code 400. Note that this response code should not must return code 400. Note that this response code should not
be generated due to an inactivity timeout as described in be generated due to an inactivity timeout as described in
section 4. section 4.
In the case of any error response outlined in this section, In the case of any error response outlined in this section,
the client NNTP should issue the QUIT command (see section the client NNTP should issue the QUIT command (see section
10.1). This will facilitate an orderly shutdown of the 10.1). This will facilitate an orderly shutdown of the
session. session.
8.1.4 Responses from servers without extensions 8.1.4 Responses from improperly implemented servers
A server NNTP that conforms to this memo but does not support Barber [Page 12]
the extensions specified here will not recognize the LIST
EXTENSIONS command and MUST consequently return code 500 or
code 501. The server NNTP SHALL stay in the same state after
returning this code. The client NNTP may try the extensions
either as the need arises or configure itself for the basic
NNTP functionality defined in this document.
8.1.5 Responses from improperly implemented servers INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
A server NNTP that improperly implements the LIST EXTENSIONS A server NNTP that improperly implements the LIST EXTENSIONS
command may return an empty list. Clients SHOULD accommodate command may return an empty list. Clients SHOULD accommodate
this protocol violation and interpret it as a response code this protocol violation and interpret it as a response code
402. 402.
The client NNTP should configure itself for the basic NNTP The client NNTP should configure itself for the basic NNTP
functionality defined in this document, or issue commands that functionality defined in this document, or issue commands that
might change the state of the server, or issue the QUIT might change the state of the server, or issue the QUIT
command (see section 10.1) if a particular extension is command (see section 10.1) if a particular extension is
required for the client to properly operate. required for the client to properly operate.
Barber [Page 13]
9. The NEWS EXCHANGE Step 9. The NEWS EXCHANGE Step
During this step, two basic types of transactions occur: During this step, two basic types of transactions occur:
o article retrieval from the server
. article retrieval from the server o article posting to the server
. article posting to the server
9.1 Article Retrieval 9.1 Article Retrieval
News reading clients have available a variety of mechanisms to News reading clients have available a variety of mechanisms to
retrieve articles via NNTP. The news articles are stored and retrieve articles via NNTP. The news articles are stored and
indexed using three types of keys. One key is the message id indexed using three types of keys. One key is the message id
of an article. According to RFC 1036, this identifier should of an article. According to RFC 1036, this identifier should
be globally unique. Another key is composed of the news group be globally unique. Another key is composed of the news group
name and the article number within that news group. That key name and the article number within that news group. That key
MUST be unique to a particular server (there will be only one MUST be unique to a particular server (there will be only one
skipping to change at line 712 skipping to change at line 702
each new article. each new article.
Article numbers MUST lie between 1 and 4,294,967,295 Article numbers MUST lie between 1 and 4,294,967,295
inclusive. The client and server SHOULD NOT use leading zeroes inclusive. The client and server SHOULD NOT use leading zeroes
in specifying article numbers, and MUST NOT use more than 16 in specifying article numbers, and MUST NOT use more than 16
digits. In some situations, the value zero replaces an article digits. In some situations, the value zero replaces an article
number to show some special situation. number to show some special situation.
9.1.1 Article Retrieval by News Group Name and Article Number 9.1.1 Article Retrieval by News Group Name and Article Number
Barber [Page 13]
INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
The following commands are used to set the current news group The following commands are used to set the current news group
name and the "current article pointer" which is used by other name and the "current article pointer" which is used by other
commands for article retrieval. At the start of a NNTP commands for article retrieval. At the start of a NNTP
session, both of these values are undefined. session, both of these values are undefined.
9.1.1.1 GROUP 9.1.1.1 GROUP
GROUP ggg GROUP ggg
The required parameter ggg is the name of the news group to be The required parameter ggg is the name of the news group to be
selected (e.g. "news.software.b"). A list of valid news groups selected (e.g. "news.software.b"). A list of valid news groups
may be obtained by using the LIST keyword. See section 9.4 may be obtained by using the LIST keyword. See section 9.4
for more information on the LIST keyword. for more information on the LIST keyword.
Barber [Page 14]
The successful selection response will return the article The successful selection response will return the article
numbers of the first and last articles in the group at the numbers of the first and last articles in the group at the
moment of selection (these numbers are referred to as the moment of selection (these numbers are referred to as the
"reported low water mark" and the "reported high water mark"), "reported low water mark" and the "reported high water mark"),
and an estimate of the number of articles on file in the and an estimate of the number of articles on file in the
group. group.
If the group is not empty, the estimate MUST be at least the If the group is not empty, the estimate MUST be at least the
actual number of articles available, and MUST be no greater actual number of articles available, and MUST be no greater
than one more than the difference between the reported low and than one more than the difference between the reported low and
high water marks. (Some implementations will actually count high water marks. (Some implementations will actually count
the number of articles on file. Others will just subtract the the number of articles on file. Others will just subtract the
low water mark from the high water mark and add one to get an low water mark from the high water mark and add one to get an
estimate.) estimate.)
If the group is empty, one of the following three situations If the group is empty, one of the following three situations
will occur. Clients MUST accept all three cases; servers MUST will occur. Clients MUST accept all three cases; servers MUST
NOT represent an empty group in any other way. NOT represent an empty group in any other way.
. The high water mark will be one less than the low water mark, o The high water mark will be one less than the low water
and the estimated article count will be zero. Servers SHOULD mark, and the estimated article count will be zero.
use this method to show an empty group. This is the only time Servers SHOULD use this method to show an empty group.
that the high water mark can be less than the low water mark. This is the only time that the high water mark can be
. All three numbers will be zero. less than the low water mark.
. The high water mark is greater than or equal to the low water o All three numbers will be zero.
mark; the estimated article count might be zero or non-zero; o The high water mark is greater than or equal to the low
if non-zero, the same requirements apply as for a non-empty water mark; the estimated article count might be zero or
group. non-zero; if non-zero, the same requirements apply as for
a non-empty group.
The set of articles in a group may change after the GROUP The set of articles in a group may change after the GROUP
command is carried out. That is: command is carried out. That is:
. articles may be removed from the group o articles may be removed from the group
. articles may be reinstated in the group with the same article
number, but those articles MUST have numbers no less than the Barber [Page 14]
reported low water mark (note that this is a reinstatement of
the previous article, not a new article reusing the number) INTERNET DRAFT S. Barber
. new articles may be added with article numbers greater than Expires: May 30, 2001 Academ Consulting Services
the reported high water mark (if an article that was the one October 2000
with the highest number has been removed, the next new article
will not have the number one greater than the reported high o articles may be reinstated in the group with the same
water mark) article number, but those articles MUST have numbers no
less than the reported low water mark (note that this is
a reinstatement of the previous article, not a new
article reusing the number)
o new articles may be added with article numbers greater
than the reported high water mark (if an article that was
the one with the highest number has been removed, the
next new article will not have the number one greater
than the reported high water mark)
Except when the group is empty and all three numbers are zero, Except when the group is empty and all three numbers are zero,
whenever a subsequent GROUP command for the same news group is whenever a subsequent GROUP command for the same news group is
issued, either by the same client or a different client, the issued, either by the same client or a different client, the
reported low water mark in the response MUST be no less than reported low water mark in the response MUST be no less than
that in any previous response for that news group sent to any that in any previous response for that news group sent to any
client. The client may make use of the low water mark to client. The client may make use of the low water mark to
remove all remembered information about articles with lower remove all remembered information about articles with lower
numbers, as these will never recur. This includes the numbers, as these will never recur. This includes the
situation when the high water mark is one less than the low situation when the high water mark is one less than the low
water mark. water mark.
Barber [Page 15]
No similar assumption can be made about the high water mark, No similar assumption can be made about the high water mark,
as this can decrease if an article is removed, and then as this can decrease if an article is removed, and then
increase again if it is reinstated or if new articles arrive. increase again if it is reinstated or if new articles arrive.
When a valid group is selected by means of this command, the When a valid group is selected by means of this command, the
internally maintained "current article pointer" MUST be set to internally maintained "current article pointer" MUST be set to
the first article in the group and the name of the current the first article in the group and the name of the current
news group MUST be set to the selected news group name. If an news group MUST be set to the selected news group name. If an
invalid group is specified, the previously selected group, if invalid group is specified, the previously selected group, if
any, and article MUST remain selected. If an empty news group any, and article MUST remain selected. If an empty news group
is selected, the "current article pointer" is in an is selected, the "current article pointer" is in an
indeterminate state and MUST NOT be used. indeterminate state and MUST NOT be used.
The GROUP keyword (or the LISTGROUP keyword, if implemented) The GROUP keyword (or the LISTGROUP keyword, if implemented)
skipping to change at line 804 skipping to change at line 805
The GROUP keyword (or the LISTGROUP keyword, if implemented) The GROUP keyword (or the LISTGROUP keyword, if implemented)
MUST be used by a client and a successful response received MUST be used by a client and a successful response received
before the any other command is used that depends on having before the any other command is used that depends on having
the "current article pointer" be valid. the "current article pointer" be valid.
9.1.1.1.1 Responses 9.1.1.1.1 Responses
211 n f l s group selected 211 n f l s group selected
(n = estimated number of articles in group, f = first (n = estimated number of articles in group, f = first
article number in the group, l = last article number in article number in the group, l = last article number
the group, s = name of the group.) in the group, s = name of the group.)
Barber [Page 15]
INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
411 no such news group 411 no such news group
9.1.1.1.2 GROUP Examples 9.1.1.1.2 GROUP Examples
Example for a group known to the server Example for a group known to the server
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
Example for a group unknown to the server Example for a group unknown to the server
[C] GROUP example.is.sob.bradner.or.barber [C] GROUP example.is.sob.bradner.or.barber
[S] 411 example.is.sob.bradner.or.barber is unknown [S] 411 example.is.sob.bradner.or.barber is unknown
9.1.1.2 LAST 9.1.1.2 LAST
LAST LAST
If the current news group is valid, the internally maintained If the current news group is valid, the internally maintained
"current article pointer" MUST be set to the previous article "current article pointer" MUST be set to the previous article
in the current news group. If already positioned at the first in the current news group. If already positioned at the first
article of the news group, an error message MUST be returned article of the news group, an error message MUST be returned
and the current article MUST remain selected. and the current article MUST remain selected.
Barber [Page 16]
There MAY be no previous article in the group, although the There MAY be no previous article in the group, although the
current article number is not the reported low water mark. current article number is not the reported low water mark.
There MUST NOT be a previous article when the current article There MUST NOT be a previous article when the current article
number is the reported low water mark. number is the reported low water mark.
Because articles can be removed and added, the results of Because articles can be removed and added, the results of
multiple LAST and NEXT commands MAY not be consistent over the multiple LAST and NEXT commands MAY not be consistent over the
life of a particular NNTP session. life of a particular NNTP session.
If successful, a response indicating the current article If successful, a response indicating the current article
skipping to change at line 856 skipping to change at line 860
9.1.1.2.1 Responses 9.1.1.2.1 Responses
223 n a article retrieved - request text separately (n = 223 n a article retrieved - request text separately (n =
article number, a = unique article id) article number, a = unique article id)
412 no news group selected 412 no news group selected
420 no current article has been selected 420 no current article has been selected
422 no previous article in this group 422 no previous article in this group
9.1.1.2.2 LAST Examples 9.1.1.2.2 LAST Examples
Barber [Page 16]
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Expires: May 30, 2001 Academ Consulting Services
October 2000
Example of a successful article retrieval using LAST Example of a successful article retrieval using LAST
[S] 200 NNTP Service Ready
[S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] NEXT [C] NEXT
[S] 223 3000237 <668929@domain.com> retrieved [S] 223 3000237 <668929@domain.com> retrieved
[C] LAST [C] LAST
[S] 223 3000234 <45223423@to.to> retrieved [S] 223 3000234 <45223423@to.to> retrieved
Example of an attempt to retrieve an article without having Example of an attempt to retrieve an article without having
selected a group (via the GROUP command) first selected a group (via the GROUP command) first
[S] 200 NNTP Service ready [S] 200 NNTP Service ready
[C] LAST [C] LAST
[S] 412 no newsgroup selected [S] 412 no newsgroup selected
Barber [Page 17]
Example of an attempt to retrieve an article using the LAST Example of an attempt to retrieve an article using the LAST
command when the current article pointer is pointing at the command when the current article pointer is pointing at the
first article in the group first article in the group
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] LAST [C] LAST
[S] 422 No previous article to retrieve [S] 422 No previous article to retrieve
Example of an attempt to retrieve an article using the LAST Example of an attempt to retrieve an article using the LAST
command when the current group selected is empty command when the current group selected is empty
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP example.empty.newsgroup [C] GROUP example.empty.newsgroup
[S] 211 0 0 0 example.empty.newsgroup [S] 211 0 0 0 example.empty.newsgroup
[C] LAST [C] LAST
[S] 420 No current article selected [S] 420 No current article selected
9.1.1.3 NEXT 9.1.1.3 NEXT
NEXT NEXT
Barber [Page 17]
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Expires: May 30, 2001 Academ Consulting Services
October 2000
If the current news group is valid, the internally maintained If the current news group is valid, the internally maintained
"current article pointer" MUST be advanced to the next article "current article pointer" MUST be advanced to the next article
in the current news group. If no more articles remain in the in the current news group. If no more articles remain in the
current group, an error message MUST be returned and the current group, an error message MUST be returned and the
current article MUST remain selected. current article MUST remain selected.
If successful, a response indicating the current article If successful, a response indicating the current article
number and the message-id string MUST be returned. No article number and the message-id string MUST be returned. No article
text is sent in response to this command. text is sent in response to this command.
9.1.1.3.1 Responses 9.1.1.3.1 Responses
223 n a article retrieved - request text separately (n = 223 n a article retrieved - request text separately (n =
article number, a = unique article id) article number, a = unique article id)
412 no news group selected 412 no news group selected
420 no current article has been selected 420 no current article has been selected
421 no next article in this group 421 no next article in this group
Barber [Page 18]
9.1.1.3.2 NEXT Examples 9.1.1.3.2 NEXT Examples
Example of a successful article retrieval using NEXT Example of a successful article retrieval using NEXT
[S] 200 NNTP Service Ready
[S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] NEXT [C] NEXT
[S] 223 3000237 <668929@domain.com> retrieved [S] 223 3000237 <668929@domain.com> retrieved
Example of an attempt to retrieve an article without having Example of an attempt to retrieve an article without having
selected a group (via the GROUP command) first selected a group (via the GROUP command) first
[S] 200 NNTP Service ready [S] 200 NNTP Service ready
[C] NEXT [C] NEXT
[S] 412 no newsgroup selected [S] 412 no newsgroup selected
Example of an attempt to retrieve an article using the NEXT Example of an attempt to retrieve an article using the NEXT
command when the current article pointer is pointing at the command when the current article pointer is pointing at the
last article in the group last article in the group
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] ARTICLE 3002322 Barber [Page 18]
[S] 220 3002322 <411@whitehouse.gov> retrieved INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
[C] ARTICLE 3002322
[S] 220 3002322 <411@whitehouse.gov> retrieved
[S] Path: pathost!demo!whitehouse!not-for-mail [S] Path: pathost!demo!whitehouse!not-for-mail
[S] From: nobody@whitehouse.gov(Demo User) [S] From: nobody@whitehouse.gov(Demo User)
[S] Newsgroups: misc.test [S] Newsgroups: misc.test
[S] Subject: I am just a test article [S] Subject: I am just a test article
[S] Date: 6 Oct 1998 04:38:40 -0500 [S] Date: 6 Oct 1998 04:38:40 -0500
[S] Organization: The White House, Washington, DC [S] Organization: The White House, Washington, DC
[S] Message-ID: <411@whitehouse.gov> [S] Message-ID: <411@whitehouse.gov>
Barber [Page 19]
[S] [S]
[S] This is just a test article. [S] This is just a test article.
[S] . [S] .
[C] NEXT [C] NEXT
[S] 422 No next article to retrieve [S] 422 No next article to retrieve
Example of an attempt to retrieve an article using the NEXT Example of an attempt to retrieve an article using the NEXT
command when the current group selected is empty command when the current group selected is empty
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP example.empty.newsgroup [C] GROUP example.empty.newsgroup
[S] 211 0 0 0 example.empty.newsgroup [S] 211 0 0 0 example.empty.newsgroup
[C] NEXT [C] NEXT
[S] 420 No current article selected [S] 420 No current article selected
9.2 Retrieval of Articles and Article Sections 9.2 Retrieval of Articles and Article Sections
There are two forms to the ARTICLE command (and the related The ARTICLE, BODY, HEAD, and STAT commands are very similar.
BODY, HEAD, and STAT commands), each using a different method They differ only in the parts of the article that are
of specifying the article to be retrieved. The first form presented to the client and in the successful response code.
specifies the article by using an argument which consists of a
message-id in angle brackets ("<" and ">"). The article number The ARTICLE command is described here in full, while the other
specified in the response to this form of the command must be commands are described in terms of the differences.
zero. The second form requires that the current news group be
valid and specifies the message by using a numeric parameter
or no parameter at all.
An article, as defined by RFC 1036, consists of two parts: the An article, as defined by RFC 1036, consists of two parts: the
article headers and the article body. When responding to an article headers and the article body. When responding to one
article command, the server returns the entire article of these commands, the server presents the entire article or
contents and does not attempt to alter or translate them in appropriate part and does not attempt to alter or translate it
any way. in any way.
Barber [Page 19]
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Expires: May 30, 2001 Academ Consulting Services
October 2000
9.2.1 ARTICLE 9.2.1 ARTICLE
ARTICLE [<message-id>|nnn] ARTICLE <message-id>
ARTICLE [number]
This response displays the header, a blank line, then the body The ARTICLE command selects an article based on the arguments
(text) of the specified article. The optional parameter nnn is and presents the header, a blank line, and the body of that
the numeric id of an article in the current news group and article. The command has two forms.
In the first form, a message-id is specified (including the
angle brackets), and the server presents the article with that
message-id in its headers. In this case, the server MUST NOT
alter the "current article pointer". This is both to
facilitate the presentation of articles that may be referenced
within another article being read, and because of the semantic
difficulties of determining the proper sequence and membership
of an article which may have been posted to more than one news
group.
In the second form, an article number may be specified. If so,
and if there is an article with that number in the currently
selected group, the server MUST set the current article
pointer to that number.
Then, whether or not a number was specified, the article
indicated by the current article pointer is presented to the
client.
Note that a previously valid article number MAY become invalid
if the article has been removed. A previously invalid article
number MAY become valid if the article has been reinstated,
but such an article number MUST be no less than the reported
low water mark for that group.
The server MUST NOT change the currently selected group as a
result of this command. The server MUST NOT change the current
selected article except when an article number argument was
provided and the article exists; in particular, it MUST NOT
change it following an unsuccessful response.
9.2.1.1 Responses
First form (message-id specified):
220 0 a article retrieved and follows (multiline, a =
unique article id)
430 no such article
502 service unavailable
Second form (optional article number specified):
Barber [Page 20] Barber [Page 20]
should be chosen from the range of articles provided when the
news group was selected. If it is omitted, the current
article is assumed. Message-id is the message id of an article
as shown in that article's header.
The internally maintained "current article pointer" MUST NOT INTERNET DRAFT S. Barber
be altered when the message-id argument is used. This is both Expires: May 30, 2001 Academ Consulting Services
to facilitate the presentation of articles that may be October 2000
referenced within an article being read, and because of the
semantic difficulties of determining the proper sequence and
membership of an article which may have been posted to more
than one news group.
When a valid article number is specified as the argument, the 220 n a article retrieved and follows (multiline, n =
internally-maintained "current article pointer" MUST be set to article number, a = unique article id)
point to retrieve article. This includes the case when an 412 no news group selected
article number is implied by the use of no argument. 420 no current article selected
423 no such article number in this group
502 service unavailable
A previously valid article number MAY become invalid if the The 420 response only occurs if an article number has been
article has been removed. A previously invalid article number specified.
MAY become valid if the article has been reinstated, but such
an article number MUST be no less than the reported low water
mark for that group.
If there is a valid article to present in a reply to this In the 220 response, the first parameter is 0 for the first
command, a response indicating the current article number (or form and the article number (within the current group) for the
zero when the message-id argument is used), a message-id second form. The second parameter is the message-id of the
string, and that text is to follow MUST be returned. article (within angle brackets). This is taken from the
message-id header line of the article (required by RFC 1036).
The message-id string is an identification string contained If there is no such line, the message-id "<0>" MUST be used
within angle brackets ("<" and ">"), which is derived from the instead (without the double quotes).
header of the article itself. The Message-ID header line
(required by RFC 1036) from the article must be used to supply
this information. If the message-id header line is missing
from the article, a single digit "0" (zero) should be supplied
within the angle brackets.
Since the message-id field is unique for each article, it may Since the message-id field is unique for each article, it may
be used by a news reading program to skip duplicate displays be used by a client to skip duplicate displays of articles
of articles that have been posted more than once, or to more that have been posted more than once, or to more than one news
than one news group. group.
9.2.1.1 Responses The article headers and body are returned as a multiline
220 n <a> article retrieved - head and body follow (n = response following the initial response line.
article number, <a> = message-id)
412 no news group has been selected
420 no current article has been selected
423 no such article number in this group
430 no such article found
502 Service unavailable
Barber [Page 21]
9.2.1.2 Examples 9.2.1.2 Examples
Example of a successful retrieval of an article (using no Example of a successful retrieval of an article (using no
article number) article number)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] ARTICLE [C] ARTICLE
[S] 220 3000234 <45223423@to.to> [S] 220 3000234 <45223423@to.to>
[S] Path: pathost!demo!somewhere!not-for-mail [S] Path: pathost!demo!somewhere!not-for-mail
[S] From: nobody@nowhere.to (Demo User) [S] From: nobody@nowhere.to (Demo User)
[S] Newsgroups: misc.test [S] Newsgroups: misc.test
[S] Subject: I am just a test article [S] Subject: I am just a test article
[S] Date: 6 Oct 1998 04:38:40 -0500 [S] Date: 6 Oct 1998 04:38:40 -0500
[S] Organization: Nowhere, To [S] Organization: Nowhere, To
[S] Message-ID: <45223423@to.to> [S] Message-ID: <45223423@to.to>
[S] Barber [Page 21]
INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
[S]
[S] This is just a test article. [S] This is just a test article.
[S] . [S] .
Example of a successful retrieval of an article by message-id Example of a successful retrieval of an article by message-id
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] ARTICLE <45223423@to.to> [C] ARTICLE <45223423@to.to>
[S] 220 0 <45223423@to.to> [S] 220 0 <45223423@to.to>
[S] Path: pathost!demo!somewhere!not-for-mail [S] Path: pathost!demo!somewhere!not-for-mail
[S] From: nobody@nowhere.to (Demo User) [S] From: nobody@nowhere.to (Demo User)
[S] Newsgroups: misc.test [S] Newsgroups: misc.test
[S] Subject: I am just a test article [S] Subject: I am just a test article
[S] Date: 6 Oct 1998 04:38:40 -0500 [S] Date: 6 Oct 1998 04:38:40 -0500
[S] Organization: Nowhere, To [S] Organization: Nowhere, To
Barber [Page 22]
[S] Message-ID: <45223423@to.to> [S] Message-ID: <45223423@to.to>
[S] [S]
[S] This is just a test article. [S] This is just a test article.
[S] . [S] .
Example of an unsuccessful retrieval of an article by message- Example of an unsuccessful retrieval of an article by message-
id id
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] ARTICLE <i.am.not.there@nowhere.to> [C] ARTICLE <i.am.not.there@nowhere.to>
[S] 430 No Such Article Found [S] 430 No Such Article Found
Example of an unsuccessful retrieval of an article by number Example of an unsuccessful retrieval of an article by number
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 news.groups [S] 211 1234 3000234 3002322 news.groups
[C] ARTICLE 300256 [C] ARTICLE 300256
[S] 423 No such article number in this group [S] 423 No such article number in this group
Example of an unsuccessful retrieval of an article by number Example of an unsuccessful retrieval of an article by number
because no news group was selected first because no news group was selected first
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] ARTICLE 300256 [C] ARTICLE 300256
[S] 412 No news group selected [S] 412 No news group selected
Barber [Page 22]
INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
Example of an attempt to retrieve an article when the current Example of an attempt to retrieve an article when the current
group selected is empty group selected is empty
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP example.empty.newsgroup [C] GROUP example.empty.newsgroup
[S] 211 0 0 0 example.empty.newsgroup [S] 211 0 0 0 example.empty.newsgroup
[C] ARTICLE [C] ARTICLE
[S] 420 No current article selected [S] 420 No current article selected
Example of a failure due to the service being unavailable Example of a failure due to the service being unavailable
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
Barber [Page 23]
[C] ARTICLE <i.am.a.test.article@nowhere.to> [C] ARTICLE <i.am.a.test.article@nowhere.to>
[S] 502 Service unavailable [S] 502 Service unavailable
9.2.2 HEAD 9.2.2 HEAD
HEAD [<message-id>|nnn]
This response displays the header of the specified article. HEAD <message-id>
The optional parameter nnn is the numeric id of an article in HEAD [number]
the current news group and should be chosen from the range of
articles provided when the news group was selected. If it is
omitted, the current article is assumed. Message-id is the
message id of an article as shown in that article's header.
The internally maintained "current article pointer" MUST NOT
be altered when the message-id argument is used. This is both
to facilitate the presentation of articles that may be
referenced within an article being read, and because of the
semantic difficulties of determining the proper sequence and
membership of an article which may have been posted to more
than one news group.
When a valid article number is specified as the argument, the The HEAD command behaves identically to the ARTICLE command
internally-maintained "current article pointer" MUST be set to except that, if the article exists, only the headers are
point to the retrieved article. This includes the case when an presented (the blank line separating the headers and body MUST
article number is implied by the use of no argument. NOT be included).
A previously valid article number MAY become invalid if the 9.2.2.1 Responses
article has been removed. A previously invalid article number
MAY become valid if the article has been reinstated, but such
an article number MUST be no less than the reported low water
mark for that group.
If there is a valid article to present in a reply to this First form (message-id specified):
command, a response indicating the current article number (or
zero when the message-id argument is used), a message-id
string, and that text is to follow MUST be returned.
The message-id string returned is an identification string 221 0 a article retrieved, headers follow (multiline)
contained within angle brackets ("<" and ">"), which is 430 no such article
derived from the header of the article itself. The Message-ID 502 service unavailable
header line (required by RFC 1036) from the article must be
used to supply this information. If the message-id header line
is missing from the article, a single digit "0" (zero) should
be supplied within the angle brackets.
Since the message-id field is unique for each article, it may Second form (optional article number specified):
be used by a news reading program to skip duplicate displays
of articles that have been posted more than once, or to more
than one news group.
Barber [Page 24] 221 n a article retrieved, headers follow (multiline)
9.2.2.1 Responses 412 no news group selected
221 n <a> article retrieved - head follows 420 no current article selected
412 no news group has been selected
420 no current article has been selected
423 no such article number in this group 423 no such article number in this group
430 no such article found 502 service unavailable
502 Service unavailable
Except that only the headers are included in the response, the
221 response behaves identically to the 220 response of the
ARTICLE command.
Barber [Page 23]
INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
9.2.2.2 Examples 9.2.2.2 Examples
Example of a successful retrieval of the headers in an article Example of a successful retrieval of the headers in an article
(using no article number) (using no article number)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] HEAD [C] HEAD
[S] 220 3000234 <45223423@to.to> [S] 220 3000234 <45223423@to.to>
[S] Path: pathost!demo!somewhere!not-for-mail [S] Path: pathost!demo!somewhere!not-for-mail
[S] From: nobody@nowhere.to (Demo User) [S] From: nobody@nowhere.to (Demo User)
[S] Newsgroups: misc.test [S] Newsgroups: misc.test
[S] Subject: I am just a test article [S] Subject: I am just a test article
[S] Date: 6 Oct 1998 04:38:40 -0500 [S] Date: 6 Oct 1998 04:38:40 -0500
[S] Organization: Nowhere, To [S] Organization: Nowhere, To
[S] Message-ID: <45223423@to.to> [S] Message-ID: <45223423@to.to>
[S] . [S] .
Example of a successful retrieval of the headers in an article Example of a successful retrieval of the headers in an article
by message-id by message-id
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] HEAD <45223423@to.to> [C] HEAD <45223423@to.to>
[S] 220 0 <45223423@to.to> [S] 220 0 <45223423@to.to>
[S] Path: pathost!demo!somewhere!not-for-mail [S] Path: pathost!demo!somewhere!not-for-mail
[S] From: nobody@nowhere.to (Demo User) [S] From: nobody@nowhere.to (Demo User)
[S] Newsgroups: misc.test [S] Newsgroups: misc.test
[S] Subject: I am just a test article [S] Subject: I am just a test article
Barber [Page 25]
[S] Date: 6 Oct 1998 04:38:40 -0500 [S] Date: 6 Oct 1998 04:38:40 -0500
[S] Organization: Nowhere, To [S] Organization: Nowhere, To
[S] Message-ID: <45223423@to.to> [S] Message-ID: <45223423@to.to>
[S] . [S] .
Example of an unsuccessful retrieval of the header of an Example of an unsuccessful retrieval of the header of an
article by message-id article by message-id
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] HEAD <i.am.not.there@nowhere.to> [C] HEAD <i.am.not.there@nowhere.to>
[S] 430 No Such Article Found [S] 430 No Such Article Found
Barber [Page 24]
INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
Example of an unsuccessful retrieval of the header of an Example of an unsuccessful retrieval of the header of an
article by number article by number
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] HEAD 300256 [C] HEAD 300256
[S] 423 No such article number in this group [S] 423 No such article number in this group
Example of an unsuccessful retrieval the header of an article Example of an unsuccessful retrieval the header of an article
by number because no news group was selected first by number because no news group was selected first
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] HEAD 300256 [C] HEAD 300256
[S] 412 No news group selected [S] 412 No news group selected
Example of an attempt to retrieve the header of an article Example of an attempt to retrieve the header of an article
when the current group selected is empty when the current group selected is empty
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP example.empty.newsgroup [C] GROUP example.empty.newsgroup
[S] 211 0 0 0 example.empty.newsgroup [S] 211 0 0 0 example.empty.newsgroup
[C] HEAD [C] HEAD
[S] 420 No current article selected [S] 420 No current article selected
Example of a failure due to the service being unavailable Example of a failure due to the service being unavailable
Barber [Page 26]
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] HEAD <i.am.a.test.article@nowhere.to> [C] HEAD <i.am.a.test.article@nowhere.to>
[S] 502 Service unavailable [S] 502 Service unavailable
9.2.3 BODY 9.2.3 BODY
BODY [<message-id>|nnn]
This response displays the body (text) of the specified BODY <message-id>
article. The optional parameter nnn is the numeric id of an BODY [number]
article in the current news group and should be chosen from
the range of articles provided when the news group was
selected. If it is omitted, the current article is assumed.
Message-id is the message id of an article as shown in that
article's header.
The internally maintained "current article pointer" MUST NOT The BODY command behaves identically to the ARTICLE command
be altered when the message-id argument is used. This is both except that, if the article exists, only the body is presented
to facilitate the presentation of articles that may be (the blank line separating the headers and body MUST NOT be
referenced within an article being read, and because of the included).
semantic difficulties of determining the proper sequence and
membership of an article which may have been posted to more
than one news group.
When a valid article number is specified, the internally- 9.2.3.1 Responses
maintained "current article pointer" MUST be set point to the
retrieve article. This includes the case when an article
number is implied by the use of no argument.
A previously valid article number MAY become invalid if the First form (message-id specified):
article has been removed. A previously invalid article number
MAY become valid if the article has been reinstated, but such
an article number MUST be no less than the reported low water
mark for that group.
If there is a valid article to present in a reply to this 222 0 a article retrieved, body follows (multiline)
command, a response indicating the current article number (or
zero when the message-id argument is used), a message-id
string, and that text is to follow MUST be returned.
The message-id string returned is an identification string Barber [Page 25]
contained within angle brackets ("<" and ">"), which is
derived from the header of the article itself. The Message-ID
header line (required by RFC 1036) from the article must be
used to supply this information. If the message-id header line
is missing from the article, a single digit "0" (zero) should
be supplied within the angle brackets.
Since the message-id field is unique for each article, it may INTERNET DRAFT S. Barber
be used by a news reading program to skip duplicate displays Expires: May 30, 2001 Academ Consulting Services
of articles that have been posted more than once, or to more October 2000
than one news group.
Barber [Page 27] 430 no such article
9.2.3.1 Responses 502 service unavailable
222 n <a> article retrieved - body follows
412 no news group has been selected Second form (optional article number specified):
420 no current article has been selected
222 n a article retrieved, body follows (multiline)
412 no news group selected
420 no current article selected
423 no such article number in this group 423 no such article number in this group
430 no such article found 502 service unavailable
502 Service unavailable
Except that only the body is included in the response, the 222
response behaves identically to the 220 response of the
ARTICLE command.
9.2.3.2 Examples 9.2.3.2 Examples
Example of a successful retrieval of the body of an article Example of a successful retrieval of the body of an article
(using no article number) (using no article number)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] BODY [C] BODY
[S] 222 3000234 <45223423@to.to> [S] 222 3000234 <45223423@to.to>
[S] This is just a test article. [S] This is just a test article.
[S] . [S] .
Example of a successful retrieval of the body of an article by Example of a successful retrieval of the body of an article by
message-id message-id
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] BODY <45223423@to.to> [C] BODY <45223423@to.to>
[S] 222 0 <45223423@to.to> [S] 222 0 <45223423@to.to>
[S] This is just a test article. [S] This is just a test article.
[S] . [S] .
Example of an unsuccessful retrieval of the body of an article Example of an unsuccessful retrieval of the body of an article
by message-id by message-id
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] BODY <i.am.not.there@nowhere.to> [C] BODY <i.am.not.there@nowhere.to>
[S] 430 No Such Article Found [S] 430 No Such Article Found
Example of an unsuccessful retrieval of the body of an article Example of an unsuccessful retrieval of the body of an article
by number by number
[S] 200 NNTP Service Ready Barber [Page 26]
[C] GROUP misc.test INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
Barber [Page 28] [S] 200 NNTP Service Ready
[C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] BODY 300256 [C] BODY 300256
[S] 423 No such article number in this group [S] 423 No such article number in this group
Example of an unsuccessful retrieval of the body of an article Example of an unsuccessful retrieval of the body of an article
by number because no news group was selected first by number because no news group was selected first
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] BODY 300256 [C] BODY 300256
[S] 412 No news group selected [S] 412 No news group selected
Example of an attempt to retrieve the body of an article when Example of an attempt to retrieve the body of an article when
the current group selected is empty the current group selected is empty
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP example.empty.newsgroup [C] GROUP example.empty.newsgroup
[S] 211 0 0 0 example.empty.newsgroup [S] 211 0 0 0 example.empty.newsgroup
[C] BODY [C] BODY
[S] 420 No current article selected [S] 420 No current article selected
Example of a failure due to the service being unavailable Example of a failure due to the service being unavailable
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] BODY <i.am.a.test.article@nowhere.to> [C] BODY <i.am.a.test.article@nowhere.to>
[S] 502 Service unavailable [S] 502 Service unavailable
9.2.4 STAT 9.2.4 STAT
STAT [<message-id>|nnn]
This response returns only status information; no article STAT <message-id>
contents are returned. The optional parameter nnn is the STAT [number]
numeric id of an article in the current news group and should
be chosen from the range of articles provided when the news
group was selected. If it is omitted, the current article is
assumed. Message-id is the message id of an article as shown
in that article's header.
The internally maintained "current article pointer" MUST NOT The STAT command behaves identically to the ARTICLE command
be altered when the message-id argument is used. This is both except that, if the article exists, it is NOT presented to the
to facilitate the presentation of articles that may be client.
referenced within an article being read, and because of the
semantic difficulties of determining the proper sequence and
membership of an article which may have been posted to more
than one news group.
Barber [Page 29] This command allows the client to determine whether an article
When a valid article number is specified, the internally- exists, and in the second form what its message-id is, without
maintained "current article pointer" MUST be set point to the having to process an arbitrary amount of text.
retrieved article. This includes the case when an article
number is implied by the use of no argument.
A previously valid article number MAY become invalid if the 9.2.4.1 Responses
article has been removed. A previously invalid article number
MAY become valid if the article has been reinstated, but such
an article number MUST be no less than the reported low water
mark for that group.
If there is a valid article to present in a reply to this First form (message-id specified):
command, a response indicating the current article number (or
zero when the message-id argument is used) and a message-id
string MUST be returned.
The message-id string returned is an identification string 223 0 a article exists
contained within angle brackets ("<" and ">"), which is 430 no such article
derived from the header of the article itself. The Message-ID
header line (required by RFC 1036) from the article must be
used to supply this information. If the message-id header line
is missing from the article, a single digit "0" (zero) should
be supplied within the angle brackets.
Since the message-id field is unique for each article, it may Barber [Page 27]
be used by a news reading program to skip duplicate displays
of articles that have been posted more than once, or to more
than one news group.
9.2.4.1 Responses INTERNET DRAFT S. Barber
223 n <a> article retrieved - request text separately Expires: May 30, 2001 Academ Consulting Services
412 no news group has been selected October 2000
420 no current article has been selected
502 service unavailable
Second form (optional article number specified):
223 n a article exists
412 no news group selected
420 no current article selected
423 no such article number in this group 423 no such article number in this group
430 no such article found 502 service unavailable
502 Service unavailable
The parameters of the 223 response are identical to those that
would have been given in a 220 response to the equivalent
ARTICLE command. However, the response is NOT multiline.
9.2.4.2 Examples 9.2.4.2 Examples
Example of STAT on an existing article (using no article Example of STAT on an existing article (using no article
number) number)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] STAT [C] STAT
[S] 223 3000234 <45223423@to.to> [S] 223 3000234 <45223423@to.to>
Barber [Page 30]
Example of a STAT of an existing article by message-id Example of a STAT of an existing article by message-id
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] STAT <45223423@to.to> [C] STAT <45223423@to.to>
[S] 223 0 <45223423@to.to> [S] 223 0 <45223423@to.to>
Example of an STAT of an article not on the server by message- Example of an STAT of an article not on the server by message-
id id
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] STAT <i.am.not.there@nowhere.to> [C] STAT <i.am.not.there@nowhere.to>
[S] 430 No Such Article Found [S] 430 No Such Article Found
Example of STAT of an article not in the server by number Example of STAT of an article not in the server by number
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] STAT 300256 Barber [Page 28]
INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
[C] STAT 300256
[S] 423 No such article number in this group [S] 423 No such article number in this group
Example of STAT of an article by number when no news group was Example of STAT of an article by number when no news group was
selected first selected first
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] STAT 300256 [C] STAT 300256
[S] 412 No news group selected [S] 412 No news group selected
Example of STAT of an article when the current group selected Example of STAT of an article when the current group selected
is empty is empty
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP example.empty.newsgroup [C] GROUP example.empty.newsgroup
[S] 211 0 0 0 example.empty.newsgroup [S] 211 0 0 0 example.empty.newsgroup
[C] STAT [C] STAT
[S] 420 No current article selected [S] 420 No current article selected
Example of a failure due to the service being unavailable Example of a failure due to the service being unavailable
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[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] STAT <i.am.a.test.article@nowhere.to> [C] STAT <i.am.a.test.article@nowhere.to>
[S] 502 Service unavailable [S] 502 Service unavailable
9.3 Article Posting 9.3 Article Posting
Article posting is done in one of two modes: individual Article posting is done in one of two modes: individual
article posting from news reading clients and article transfer article posting from news reading clients and article transfer
from other news servers. from other news servers.
9.3.1 POST 9.3.1 POST
skipping to change at line 1649 skipping to change at line 1505
Article posting is done in one of two modes: individual Article posting is done in one of two modes: individual
article posting from news reading clients and article transfer article posting from news reading clients and article transfer
from other news servers. from other news servers.
9.3.1 POST 9.3.1 POST
POST POST
If posting is allowed, response code 340 MUST be returned to If posting is allowed, response code 340 MUST be returned to
indicate that the article to be posted should be sent. indicate that the article to be posted should be sent.
Response code 440 MUST be sent if that posting is prohibited Response code 440 MUST be sent if that posting is prohibited
for some installation-dependent reason. for some installation-dependent reason.
If posting is permitted, the article MUST be presented to the If posting is permitted, the article MUST be presented to the
server by the client in the format specified by RFC 1036. The server by the client in the format specified by RFC 1036. The
text forming the header and body of the message to be posted text forming the header and body of the message to be posted
MUST be sent by the client using the conventions for text MUST be sent by the client using the conventions for text
received from the news server: A single period (".") on a line received from the news server: A single period (".") on a line
indicates the end of the text, with lines starting with a indicates the end of the text, with lines starting with a
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period in the original text having that period doubled during period in the original text having that period doubled during
transmission. transmission.
Following the presentation of the termination sequence by the Following the presentation of the termination sequence by the
client, the server MUST return a response code indicating client, the server MUST return a response code indicating
success or failure of the article transfer. Note that response success or failure of the article transfer. Note that response
codes 340 and 440 are used in direct response to the POST codes 340 and 440 are used in direct response to the POST
command. Others are returned following the sending of the command. Others are returned following the sending of the
article. article.
skipping to change at line 1681 skipping to change at line 1545
be posted to the server installation's news posting software, be posted to the server installation's news posting software,
which is not part of this specification. which is not part of this specification.
9.3.1.1 Responses 9.3.1.1 Responses
240 article received ok 240 article received ok
340 send article to be posted. End with <CR-LF>.<CR-LF> 340 send article to be posted. End with <CR-LF>.<CR-LF>
440 posting not allowed 440 posting not allowed
441 posting failed 441 posting failed
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9.3.1.2 Examples 9.3.1.2 Examples
Example of a successful posting Example of a successful posting
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] POST [C] POST
[S] 340 Input article. End with <CR-LF>.<CR-LF> [S] 340 Input article. End with <CR-LF>.<CR-LF>
[C] From: demo@testdomain.com(Demo User) [C] From: demo@testdomain.com(Demo User)
[C] Newsgroups: misc.test [C] Newsgroups: misc.test
[C] Subject: I am just a test article [C] Subject: I am just a test article
[C] Organization: Testdomain, USA [C] Organization: Testdomain, USA
[C] [C]
[C] This is just a test article. [C] This is just a test article.
[C] . [C] .
[S] 240 Article received ok [S] 240 Article received ok
Example of an unsuccessful posting Example of an unsuccessful posting
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] POST [C] POST
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[S] 340 Input article. End with <CR-LF>.<CR-LF>
[C] From: demo@testdomain.com(Demo User) [C] From: demo@testdomain.com(Demo User)
[C] Newsgroups: misc.test [C] Newsgroups: misc.test
[C] Subject: I am just a test article [C] Subject: I am just a test article
[C] Organization: Testdomain, USA [C] Organization: Testdomain, USA
[C] [C]
[C] This is just a test article. [C] This is just a test article.
[C] . [C] .
[S] 441 Posting failed [S] 441 Posting failed
Example of an attempt to posting when posting is not allowed Example of an attempt to posting when posting is not allowed
[S] 201 NNTP Service Ready, read-only [S] 201 NNTP Service Ready, read-only
[C] POST [C] POST
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[S] 440 Posting not permitted [S] 440 Posting not permitted
9.3.2 IHAVE 9.3.2 IHAVE
IHAVE <message-id> IHAVE <message-id>
The IHAVE command informs the server that the client has an The IHAVE command informs the server that the client has an
article whose id is <message-id>. If the server desires a copy article whose id is <message-id>. If the server desires a copy
of that article, it MUST return a response instructing the of that article, it MUST return a response instructing the
client to send the entire article. If the server does not want client to send the entire article. If the server does not want
skipping to change at line 1768 skipping to change at line 1615
This function differs from the POST command in that it is This function differs from the POST command in that it is
intended for use in transferring already-posted articles intended for use in transferring already-posted articles
between hosts. It SHOULD NOT be used when the client is a between hosts. It SHOULD NOT be used when the client is a
personal news reading program. In particular, this function personal news reading program. In particular, this function
will invoke the server's news posting program with the will invoke the server's news posting program with the
appropriate settings (flags, options, etc.) to indicate that appropriate settings (flags, options, etc.) to indicate that
the forthcoming article is being forwarded from another host. the forthcoming article is being forwarded from another host.
However, the server MAY elect not to post or forward the However, the server MAY elect not to post or forward the
article if after further examination of the article it deems article if after further examination of the article it deems
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it inappropriate to do so. Reasons for such subsequent it inappropriate to do so. Reasons for such subsequent
rejection of an article may include such problems as rejection of an article may include such problems as
inappropriate news groups or distributions, disk space inappropriate news groups or distributions, disk space
limitations, article lengths, garbled headers, and the like. limitations, article lengths, garbled headers, and the like.
These are typically restrictions enforced by the server host's These are typically restrictions enforced by the server host's
news software and not necessarily the NNTP server itself. news software and not necessarily the NNTP server itself.
9.3.2.1 Responses 9.3.2.1 Responses
235 article transferred ok 235 article transferred ok
335 send article to be transferred. End with <CR- 335 send article to be transferred. End with <CR-
LF>.<CR-LF> LF>.<CR-LF>
435 article not wanted - do not send it 435 article not wanted - do not send it
436 transfer failed - try again later 436 transfer failed - try again later
437 article rejected - do not try again 437 article rejected - do not try again
Because some host news posting software may not be able to Because some host news posting software may not be able to
immediately render status on the whether an article is immediately render status on the whether an article is
inappropriate for posting or forwarding, an NNTP server MAY inappropriate for posting or forwarding, an NNTP server MAY
acknowledge the successful transfer of the article and later acknowledge the successful transfer of the article and later
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silently discard it. Thus, an NNTP server MAY return the 235 silently discard it. Thus, an NNTP server MAY return the 235
acknowledgment code and later discard the received article. acknowledgment code and later discard the received article.
9.3.2.2 Examples 9.3.2.2 Examples
Example of successfully sending an article to another site Example of successfully sending an article to another site
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] IHAVE <i.am.an.article.you.will.want@nowhere.to> [C] IHAVE <i.am.an.article.you.will.want@nowhere.to>
[S] 335 Send it. End with <CR-LF>.<CR-LF> [S] 335 Send it. End with <CR-LF>.<CR-LF>
[C] Path: pathost!demo!somewhere!not-for-mail [C] Path: pathost!demo!somewhere!not-for-mail
[C] From: nobody@nowhere.to (Demo User) [C] From: nobody@nowhere.to (Demo User)
[C] Newsgroups: misc.test [C] Newsgroups: misc.test
[C] Subject: I am just a test article [C] Subject: I am just a test article
[C] Date: 6 Oct 1998 04:38:40 -0500 [C] Date: 6 Oct 1998 04:38:40 -0500
[C] Organization: Nowhere, To [C] Organization: Nowhere, To
[C] Message-ID: <i.am.a.test.article@nowhere.to> [C] Message-ID: <i.am.a.test.article@nowhere.to>
[C] [C]
[C] This is just a test article. [C] This is just a test article.
[C] . [C] .
[S] 235 Article transferred ok [S] 235 Article transferred ok
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Example of sending an article to another site that rejects it Example of sending an article to another site that rejects it
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] IHAVE <i.am.an.article.you.will.want@nowhere.to> [C] IHAVE <i.am.an.article.you.will.want@nowhere.to>
[S] 335 Send it. End with <CR-LF>.<CR-LF> [S] 335 Send it. End with <CR-LF>.<CR-LF>
[C] Path: pathost!demo!somewhere!not-for-mail [C] Path: pathost!demo!somewhere!not-for-mail
[C] From: nobody@nowhere.to (Demo User) [C] From: nobody@nowhere.to (Demo User)
[C] Newsgroups: misc.test [C] Newsgroups: misc.test
[C] Subject: I am just a test article [C] Subject: I am just a test article
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[C] Date: 6 Oct 1998 04:38:40 -0500 [C] Date: 6 Oct 1998 04:38:40 -0500
[C] Organization: Nowhere, To [C] Organization: Nowhere, To
[C] Message-ID: <i.am.a.test.article@nowhere.to> [C] Message-ID: <i.am.a.test.article@nowhere.to>
[C] [C]
[C] This is just a test article. [C] This is just a test article.
[C] . [C] .
[S] 437 Article rejected. Don't send again [S] 437 Article rejected. Don't send again
Example of sending an article to another site where the Example of sending an article to another site where the
transfer fails transfer fails
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] IHAVE <i.am.an.article.you.will.want@nowhere.to> [C] IHAVE <i.am.an.article.you.will.want@nowhere.to>
[S] 335 Send it. End with <CR-LF>.<CR-LF> [S] 335 Send it. End with <CR-LF>.<CR-LF>
[C] Path: pathost!demo!somewhere!not-for-mail [C] Path: pathost!demo!somewhere!not-for-mail
[C] From: nobody@nowhere.to (Demo User) [C] From: nobody@nowhere.to (Demo User)
[C] Newsgroups: misc.test [C] Newsgroups: misc.test
[C] Subject: I am just a test article [C] Subject: I am just a test article
[C] Date: 6 Oct 1998 04:38:40 -0500 [C] Date: 6 Oct 1998 04:38:40 -0500
[C] Organization: Nowhere, To [C] Organization: Nowhere, To
[C] Message-ID: <i.am.a.test.article@nowhere.to> [C] Message-ID: <i.am.a.test.article@nowhere.to>
[C] [C]
[C] This is just a test article. [C] This is just a test article.
[C] . [C] .
[S] 436 Transfer failed [S] 436 Transfer failed
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Example of sending an article to another site that rejects it Example of sending an article to another site that rejects it
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] IHAVE <i.am.an.article.you.will.want@nowhere.to> [C] IHAVE <i.am.an.article.you.will.want@nowhere.to>
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[S] 335 Send it. End with <CR-LF>.<CR-LF> [S] 335 Send it. End with <CR-LF>.<CR-LF>
[C] Path: pathost!demo!somewhere!not-for-mail [C] Path: pathost!demo!somewhere!not-for-mail
[C] From: nobody@nowhere.to (Demo User) [C] From: nobody@nowhere.to (Demo User)
[C] Newsgroups: misc.test [C] Newsgroups: misc.test
[C] Subject: I am just a test article [C] Subject: I am just a test article
[C] Date: 6 Oct 1998 04:38:40 -0500 [C] Date: 6 Oct 1998 04:38:40 -0500
[C] Organization: Nowhere, To [C] Organization: Nowhere, To
[C] Message-ID: <i.am.a.test.article@nowhere.to> [C] Message-ID: <i.am.a.test.article@nowhere.to>
[C] [C]
[C] This is just a test article. [C] This is just a test article.
[C] . [C] .
[S] 435 Don't send it again [S] 435 Don't send it again
9.4 The LIST Keyword 9.4 The LIST Keyword
9.4.1 LIST 9.4.1 LIST
LIST [ACTIVE [wildmat]] LIST [ACTIVE [wildmat]]
The response to the LIST keyword with no parameters returns a The response to the LIST keyword with no parameters returns a
list of valid news groups and associated information. Each list of valid news groups and associated information. Each
news group is sent as a line of text in the following format: news group is sent as a line of text in the following format:
group first last status group first last status
where <group> is the name of the news group, <last> is the where <group> is the name of the news group, <last> is the
number of the last known article currently in that news group, number of the last known article currently in that news group,
<first> is the number of the first article currently in the <first> is the number of the first article currently in the
news group, and <status> indicates the current status of the news group, and <status> indicates the current status of the
group on this server. Typically, the <status> will be consist group on this server. Typically, the <status> will be consist
of the US-ASCII character `y' where posting is permitted, `n' of the US-ASCII character 'y' where posting is permitted, 'n'
where posting is not permitted and `m' where postings will be where posting is not permitted and 'm' where postings will be
forwarded to the news group moderator by the news server. forwarded to the news group moderator by the news server.
Other status strings may exist. The definition of these other Other status strings may exist. The definition of these other
values and the circumstances under which they are returned is values and the circumstances under which they are returned is
covered in other specifications. covered in other specifications.
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The <first> and <last> fields will always be numeric. They The <first> and <last> fields will always be numeric. They
may have leading zeros. The <first> field corresponds to the may have leading zeros. The <first> field corresponds to the
"reported low water mark" and the <last> field corresponds to "reported low water mark" and the <last> field corresponds to
the "reported high water mark" described in the GROUP command the "reported high water mark" described in the GROUP command
(see Section 9.1.1.1). (see Section 9.1.1.1).
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The status of a news group only indicates how posts to that The status of a news group only indicates how posts to that
news group are processed. It does not if the current client is news group are processed. It does not if the current client is
permitted to post. That is indicated by the status code permitted to post. That is indicated by the status code
returned as part of the greeting. returned as part of the greeting.
Please note that an empty list (i.e., the text body returned Please note that an empty list (i.e., the text body returned
by this command consists only of the terminating period) is a by this command consists only of the terminating period) is a
possible valid response, and indicates that there are possible valid response, and indicates that there are
currently no valid news groups. currently no valid news groups.
skipping to change at line 1967 skipping to change at line 1778
currently no valid news groups. currently no valid news groups.
If the optional wildmat parameter is specified, the list is If the optional wildmat parameter is specified, the list is
limited to only the groups that match the pattern. limited to only the groups that match the pattern.
Specifying a single group is usually very efficient for the Specifying a single group is usually very efficient for the
server. Multiple groups may be specified by using wildmat server. Multiple groups may be specified by using wildmat
patterns (described in section 5). patterns (described in section 5).
9.4.1.1 Responses 9.4.1.1 Responses
215 list of news groups follows 215 list of news groups follows
9.4.1.2 Examples 9.4.1.2 Examples
Example of LIST returning a list of news groups Example of LIST returning a list of news groups
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST [C] LIST
[S] 215 list of news groups follows [S] 215 list of news groups follows
[S] misc.test 3000234 3002322 y [S] misc.test 3000234 3002322 y
[S] alt.fc-writers.recovery 1 4 y [S] alt.fc-writers.recovery 1 4 y
[S] tx.natives.recovery 56 89 y [S] tx.natives.recovery 56 89 y
[S] . [S] .
Example of LIST returning no news groups Example of LIST returning no news groups
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST [C] LIST
[S] 215 list of news groups follows [S] 215 list of news groups follows
[S] . [S] .
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9.4.2 LIST ACTIVE.TIMES 9.4.2 LIST ACTIVE.TIMES
LIST ACTIVE.TIMES [wildmat] LIST ACTIVE.TIMES [wildmat]
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The active.times file is maintained by some news transport The active.times file is maintained by some news transport
systems to contain information about who created a particular systems to contain information about who created a particular
news group and when. The format of this file includes three news group and when. The format of this file includes three
fields. The first field is the name of the news group. The fields. The first field is the name of the news group. The
second is the time when this group was created on this news second is the time when this group was created on this news
server measured in seconds since the start of January 1, 1970. server measured in seconds since the start of January 1, 1970.
The third is the email address of the entity that created the The third is the email address of the entity that created the
news group. When executed, the information is displayed news group. When executed, the information is displayed
following the 215 response. When display is completed, the following the 215 response. When display is completed, the
server will send a period on a line by itself. If the server will send a period on a line by itself. If the
skipping to change at line 2031 skipping to change at line 1838
9.4.2.1 Responses 9.4.2.1 Responses
215 information follows 215 information follows
501 Syntax error 501 Syntax error
503 program error, function not performed 503 program error, function not performed
9.4.2.2 Examples 9.4.2.2 Examples
Example of LIST ACTIVE.TIMES returning a list of news groups Example of LIST ACTIVE.TIMES returning a list of news groups
[S] 200 NNTP Service Ready
[S] 200 NNTP Service Ready
[C] LIST ACTIVE.TIMES [C] LIST ACTIVE.TIMES
[S] 215 information follows [S] 215 information follows
[S] misc.test 930445408 <creatme@isc.org> [S] misc.test 930445408 <creatme@isc.org>
[S] alt.rfc-writers.recovery 930562309 <m@nowhere.to> [S] alt.rfc-writers.recovery 930562309 <m@nowhere.to>
[S] tx.natives.recovery 930678923 <sob@academ.com> [S] tx.natives.recovery 930678923 <sob@academ.com>
[S] . [S] .
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Example of LIST ACTIVE.TIMES returning an error (The server Example of LIST ACTIVE.TIMES returning an error (The server
software is not configured to maintain this information, but software is not configured to maintain this information, but
does recognize the command as valid.) does recognize the command as valid.)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST ACTIVE.TIMES [C] LIST ACTIVE.TIMES
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[S] 503 program error, function not performed [S] 503 program error, function not performed
Example of LIST ACTIVE.TIMES sent to a server that does not Example of LIST ACTIVE.TIMES sent to a server that does not
recognize this argument (e.g. The software does not maintain recognize this argument (e.g. The software does not maintain
this information.) this information.)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST ACTIVE.TIMES [C] LIST ACTIVE.TIMES
[S] 501 Syntax Error [S] 501 Syntax Error
9.4.3 LIST DISTRIBUTIONS 9.4.3 LIST DISTRIBUTIONS
LIST DISTRIBUTIONS LIST DISTRIBUTIONS
The distributions file is maintained by some news transport The distributions file is maintained by some news transport
systems to contain information about valid values for the systems to contain information about valid values for the
Distribution: line in a news article header and about what the Distribution: line in a news article header and about what the
values mean. Each line contains two fields, the value and a values mean. Each line contains two fields, the value and a
skipping to change at line 2089 skipping to change at line 1891
recognize this command, it SHOULD return the 501 error recognize this command, it SHOULD return the 501 error
response. response.
9.4.3.1 Responses 9.4.3.1 Responses
215 information follows 215 information follows
501 Syntax error 501 Syntax error
503 program error, function not performed 503 program error, function not performed
9.4.3.2 Examples 9.4.3.2 Examples
Example of LIST DISTRIBUTIONS returning a list of news groups Example of LIST DISTRIBUTIONS returning a list of news groups
[S] 200 NNTP Service Ready
[S] 200 NNTP Service Ready
[C] LIST DISTRIBUTIONS [C] LIST DISTRIBUTIONS
[S] 215 information follows [S] 215 information follows
[S] usa United States of America [S] usa United States of America
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[S] na North America [S] na North America
[S] world All over the World [S] world All over the World
[S] . [S] .
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Example of LIST DISTRIBUTIONS returning an error (e.g. The Example of LIST DISTRIBUTIONS returning an error (e.g. The
server software is not configured to maintain this server software is not configured to maintain this
information, but does recognize the command as valid.) information, but does recognize the command as valid.)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST DISTRIBUTIONS [C] LIST DISTRIBUTIONS
[S] 503 program error, function not performed [S] 503 program error, function not performed
Example of LIST DISTRIBUTIONS sent to a server that does not Example of LIST DISTRIBUTIONS sent to a server that does not
recognize the command (e.g. The server does not maintain this recognize the command (e.g. The server does not maintain this
information regardless of configuration.) information regardless of configuration.)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST DISTRIBUTIONS [C] LIST DISTRIBUTIONS
[S] 501 Syntax Error [S] 501 Syntax Error
9.4.4 LIST DISTRIB.PATS 9.4.4 LIST DISTRIB.PATS
LIST DISTRIB.PATS LIST DISTRIB.PATS
The distrib.pats file is maintained by some news transport The distrib.pats file is maintained by some news transport
systems to allow clients to choose a value for the systems to allow clients to choose a value for the
Distribution: line in the header of a news article being Distribution: line in the header of a news article being
posted. The information returned consists of lines, in no posted. The information returned consists of lines, in no
skipping to change at line 2136 skipping to change at line 1934
LIST DISTRIB.PATS LIST DISTRIB.PATS
The distrib.pats file is maintained by some news transport The distrib.pats file is maintained by some news transport
systems to allow clients to choose a value for the systems to allow clients to choose a value for the
Distribution: line in the header of a news article being Distribution: line in the header of a news article being
posted. The information returned consists of lines, in no posted. The information returned consists of lines, in no
particular order, each of which contains three fields particular order, each of which contains three fields
separated by colons. These fields are a weight, a group name separated by colons. These fields are a weight, a group name
or wildmat pattern, and a Distribution: value, in that order. or wildmat pattern, and a Distribution: value, in that order.
The client MAY use this information to select a Distribution: The client MAY use this information to select a Distribution:
value based on the name of a newsgroup. To do so, it should value based on the name of a newsgroup. To do so, it should
determine the lines whose second field matches the newsgroup determine the lines whose second field matches the newsgroup
name, select that line with the highest weight (with 0 being name, select that line with the highest weight (with 0 being
the lowest), and use the Distribution: field from that line. the lowest), and use the Distribution: field from that line.
When executed, the information is displayed following the 215 When executed, the information is displayed following the 215
response. When display is completed, the server will send a response. When display is completed, the server will send a
period on a line by itself. If the information is not period on a line by itself. If the information is not
available, the server will return the 503 error response. If available, the server will return the 503 error response. If
this command is not recognized, the server SHOULD return the this command is not recognized, the server SHOULD return the
501 error response. 501 error response.
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9.4.4.1 Responses 9.4.4.1 Responses
215 information follows 215 information follows
501 Syntax error 501 Syntax error
503 program error, function not performed 503 program error, function not performed
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9.4.4.2 Examples 9.4.4.2 Examples
Example of LIST DISTRIB.PATS returning a list of news groups Example of LIST DISTRIB.PATS returning a list of news groups
[S] 200 NNTP Service Ready
[S] 200 NNTP Service Ready
[C] LIST DISTRIB.PATS [C] LIST DISTRIB.PATS
[S] 215 information follows [S] 215 information follows
[S] 10:local.*:local [S] 10:local.*:local
[S] . [S] .
Example of LIST DISTRIB.PATS returning an error (e.g. The Example of LIST DISTRIB.PATS returning an error (e.g. The
server software is not configured to maintain this server software is not configured to maintain this
information, but does recognize the command as valid.) information, but does recognize the command as valid.)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST DISTRIB.PATS [C] LIST DISTRIB.PATS
[S] 503 program error, function not performed [S] 503 program error, function not performed
Example of LIST DISTRIB.PATS sent to a server that does not Example of LIST DISTRIB.PATS sent to a server that does not
recognize the command (e.g. The software does not maintain recognize the command (e.g. The software does not maintain
this information regardless of configuration.) this information regardless of configuration.)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST DISTRIB.PATS [C] LIST DISTRIB.PATS
[S] 501 Syntax Error [S] 501 Syntax Error
9.4.5 LIST NEWSGROUPS 9.4.5 LIST NEWSGROUPS
LIST NEWSGROUPS [wildmat] LIST NEWSGROUPS [wildmat]
The newsgroups file is maintained by some news transport The newsgroups file is maintained by some news transport
systems to contain the name of each news group that is systems to contain the name of each news group that is
active on the server and a short description about the active on the server and a short description about the
purpose of each news group. Each line in the file contains purpose of each news group. Each line in the file contains
skipping to change at line 2204 skipping to change at line 1997
The newsgroups file is maintained by some news transport The newsgroups file is maintained by some news transport
systems to contain the name of each news group that is systems to contain the name of each news group that is
active on the server and a short description about the active on the server and a short description about the
purpose of each news group. Each line in the file contains purpose of each news group. Each line in the file contains
two fields, the news group name and a short explanation of two fields, the news group name and a short explanation of
the purpose of that news group. When executed, the the purpose of that news group. When executed, the
information is displayed following the 215 response. When information is displayed following the 215 response. When
display is completed, the server will send a period on a display is completed, the server will send a period on a
line by itself. If the information is not available, the line by itself. If the information is not available, the
server will return the 503 response. If the server does not server will return the 503 response. If the server does not
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recognize the command it should return a 501 response. If recognize the command it should return a 501 response. If
the optional matching parameter is specified, the list is the optional matching parameter is specified, the list is
limited to only the groups that match the pattern (no limited to only the groups that match the pattern (no
matching is done on the group descriptions). Specifying a matching is done on the group descriptions). Specifying a
single group is usually very efficient for the server, and single group is usually very efficient for the server, and
multiple groups may be specified by using wildmat patterns multiple groups may be specified by using a wildmat(see
section 5), not regular expressions. If nothing is matched
Barber [Page 42] an empty list is returned, not an error.
(see section 5), not regular expressions. If nothing is
matched an empty list is returned, not an error.
9.4.5.1 Responses 9.4.5.1 Responses
215 information follows 215 information follows
501 Syntax error 501 Syntax error
503 program error, function not performed 503 program error, function not performed
9.4.5.2 Examples 9.4.5.2 Examples
Example of LIST NEWSGROUPS returning a list of news groups Example of LIST NEWSGROUPS returning a list of news groups
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST NEWSGROUPS [C] LIST NEWSGROUPS
[S] 215 information follows [S] 215 information follows
[S] misc.test General Usenet testing [S] misc.test General Usenet testing
[S] alt.rfc-writers.recovery RFC Writers Recovery [S] alt.rfc-writers.recovery RFC Writers Recovery
[S] tx.natives.recovery Texas Natives Recovery [S] tx.natives.recovery Texas Natives Recovery
[S] . [S] .
Example of LIST NEWSGROUPS returning an error (e.g. The server Example of LIST NEWSGROUPS returning an error (e.g. The server
software recognizes the command as valid, but the information software recognizes the command as valid, but the information
is not available.) is not available.)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST NEWSGROUPS [C] LIST NEWSGROUPS
[S] 503 program error, function not performed [S] 503 program error, function not performed
9.5 Standard extensions 9.5 Standard extensions
Each of the following sections describes an extension that a Each of the following sections describes an extension that a
server MAY provide. If the server provides the extension, it server MAY provide. If the server provides the extension, it
MUST include the appropriate extension label in the response MUST include the appropriate extension label in the response
to LIST EXTENSIONS. If it does not provide it, it MUST NOT to LIST EXTENSIONS. If it does not provide it, it MUST NOT
include the appropriate extension label. The descriptions of include the appropriate extension label. The descriptions of
facilities in each section are written as if the extension is facilities in each section are written as if the extension is
skipping to change at line 2256 skipping to change at line 2046
[S] 503 program error, function not performed [S] 503 program error, function not performed
9.5 Standard extensions 9.5 Standard extensions
Each of the following sections describes an extension that a Each of the following sections describes an extension that a
server MAY provide. If the server provides the extension, it server MAY provide. If the server provides the extension, it
MUST include the appropriate extension label in the response MUST include the appropriate extension label in the response
to LIST EXTENSIONS. If it does not provide it, it MUST NOT to LIST EXTENSIONS. If it does not provide it, it MUST NOT
include the appropriate extension label. The descriptions of include the appropriate extension label. The descriptions of
facilities in each section are written as if the extension is facilities in each section are written as if the extension is
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provided. If it is not provided, the entire section should be provided. If it is not provided, the entire section should be
ignored. ignored.
9.5.1 LISTGROUP extension 9.5.1 LISTGROUP extension
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This extension provides one command and has the extension This extension provides one command and has the extension
label LISTGROUP. label LISTGROUP.
9.5.1.1 The LISTGROUP Command 9.5.1.1 The LISTGROUP Command
LISTGROUP [ggg] LISTGROUP [ggg]
The LISTGROUP command is used to get a listing of all the The LISTGROUP command is used to get a listing of all the
article numbers in a particular news group. article numbers in a particular news group.
The optional parameter ggg is the name of the news group to The optional parameter ggg is the name of the news group to
be selected (e.g. "news.software.b"). A list of valid news be selected (e.g. "news.software.b"). A list of valid news
groups may be obtained from the LIST command. If no group is groups may be obtained from the LIST command. If no group
specified, the current group is used as the default is specified, the current group is used as the default
argument. argument.
The successful selection response will be a list of the The successful selection response will be a list of the
article numbers in the group followed by a period on a line article numbers in the group followed by a period on a line
by itself. The list starts on the next line following the by itself. The list starts on the next line following the
211 response code. 211 response code.
When a valid group is selected by means of this command, the When a valid group is selected by means of this command,
internally maintained "current article pointer" MUST be set the internally maintained "current article pointer" MUST be
to the first article in the group and the name of the set to the first article in the group and the name of the
current news group MUST be set to the selected news group current news group MUST be set to the selected news group
name. If an invalid group is specified, the previously name. If an invalid group is specified, the previously
selected group and article remain selected. If an empty selected group and article remain selected. If an empty
news group is selected, the "current article pointer" may be news group is selected, the "current article pointer" may
in an indeterminate state and should not be used. be in an indeterminate state and should not be used.
The LISTGROUP keyword MAY be used by a client as a The LISTGROUP keyword MAY be used by a client as a
replacement for the GROUP command in establishing a valid replacement for the GROUP command in establishing a valid
"current article pointer." After a successful response is "current article pointer." After a successful response is
received, any other command may be used that depends on received, any other command may be used that depends on
having the "current article pointer" be valid. having the "current article pointer" be valid.
The group name MUST match a news group obtained from the The group name MUST match a news group obtained from the
LIST command or an error will result, else the server will LIST command or an error will result, else the server will
respond with the 411 error code. respond with the 411 error code.
A server that does not implement this command SHOULD return A server that does not implement this command SHOULD return
a 500 error response. a 500 error response.
9.5.1.1.1 Responses 9.5.1.1.1 Responses
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211 list of article numbers follow 211 list of article numbers follow
411 No such group 411 No such group
412 Not currently in news group 412 Not currently in news group
500 Command not recognized 500 Command not recognized
9.5.1.1.2 Examples 9.5.1.1.2 Examples
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Example of a successful execution with a group that exists on Example of a successful execution with a group that exists on
the server the server
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LISTGROUP misc.test [C] LISTGROUP misc.test
[S] 211 list of article numbers follow [S] 211 list of article numbers follow
[S] 3000234 [S] 3000234
[S] 3000237 [S] 3000237
[S] 3000238 [S] 3000238
[S] 3000239 [S] 3000239
[S] 3002322 [S] 3002322
[S] . [S] .
Example of an unsuccessful execution with a group that does Example of an unsuccessful execution with a group that does
not exist on the server not exist on the server
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LISTGROUP this.group.is.not.here [C] LISTGROUP this.group.is.not.here
[S] 411 no such group [S] 411 no such group
Example of an attempt to retrieve an article when the current Example of an attempt to retrieve an article when the current
group selected is empty group selected is empty
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LISTGROUP example.empty.newsgroup [C] LISTGROUP example.empty.newsgroup
[S] 412 No current article selected [S] 412 No current article selected
9.5.2 The OVER Extension 9.5.2 The OVER Extension
This extension provides two commands, OVER and LIST This extension provides two commands, OVER and LIST
OVERVIEW.FMT. The label for this extension is OVER. OVERVIEW.FMT. The label for this extension is OVER.
9.5.2.1 LIST OVERVIEW.FMT 9.5.2.1 LIST OVERVIEW.FMT
LIST OVERVIEW.FMT LIST OVERVIEW.FMT
skipping to change at line 2363 skipping to change at line 2148
9.5.2 The OVER Extension 9.5.2 The OVER Extension
This extension provides two commands, OVER and LIST This extension provides two commands, OVER and LIST
OVERVIEW.FMT. The label for this extension is OVER. OVERVIEW.FMT. The label for this extension is OVER.
9.5.2.1 LIST OVERVIEW.FMT 9.5.2.1 LIST OVERVIEW.FMT
LIST OVERVIEW.FMT LIST OVERVIEW.FMT
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The overview.fmt file is maintained by some news transport The overview.fmt file is maintained by some news transport
systems to contain the order in which header information is systems to contain the order in which header information is
stored in the overview databases for each news group. When stored in the overview databases for each news group. When
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executed, news article header fields are displayed one line at executed, news article header fields are displayed one line at
a time in the order in which they are stored in the overview a time in the order in which they are stored in the overview
database[7] following the 215 response. When display is database[6] following the 215 response. When display is
completed, the server will send a period on a line by itself. completed, the server will send a period on a line by itself.
If the information is not available, the server will return If the information is not available, the server will return
the 503 response. the 503 response.
If the header has the word "full" (without quotes) after the If the header has the word "full" (without quotes) after the
colon, the header's name is prepended to its field in the colon, the header's name is prepended to its field in the
output returned by the server. output returned by the server.
This is command is part of the optional OVER extension which This is command is part of the optional OVER extension which
includes the OVER command defined in section 9.5.2.2. If the includes the OVER command defined in section . If the OVER
OVER extension is not implemented, then this command MUST NOT extension is not implemented, then this command MUST NOT be
be implemented. If that case, the server MUST return a 501 implemented. If that case, the server MUST return a 501 error
error response when this command is presented by the client. response when this command is presented by the client.
9.5.2.1.1 Responses 9.5.2.1.1 Responses
215 information follows 215 information follows
501 Syntax Error 501 Syntax Error
503 program error, function not performed 503 program error, function not performed
9.5.2.1.2 Examples 9.5.2.1.2 Examples
Example of LIST OVERVIEW.FMT returning a list of news groups Example of LIST OVERVIEW.FMT returning a list of news groups
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST OVERVIEW.FMT [C] LIST OVERVIEW.FMT
[S] 215 Order of fields in overview database. [S] 215 Order of fields in overview database.
[S] Subject: [S] Subject:
[S] From: [S] From:
[S] Date: [S] Date:
[S] Message-ID: [S] Message-ID:
[S] . [S] .
Example of LIST OVERVIEW.FMT returning an error Example of LIST OVERVIEW.FMT returning an error
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] LIST OVERVIEW.FMT [C] LIST OVERVIEW.FMT
[S] 503 program error, function not performed [S] 503 program error, function not performed
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9.5.2.2 OVER 9.5.2.2 OVER
OVER [range] OVER [range]
The OVER command returns specific header information for the The OVER command returns specific header information for the
article(s) specified from the current selected group. The article(s) specified from the current selected group. The
information returned in the response to this command can be information returned in the response to this command can be
used by clients to follow discussion threads. used by clients to follow discussion threads.
The optional range argument may be any of the following: The optional range argument may be any of the following:
o an article number
. an article number o an article number followed by a dash to indicate all
. an article number followed by a dash to indicate all following following
. an article number followed by a dash followed by another o an article number followed by a dash followed by another
article number article number
If no argument is specified, then information from the current If no argument is specified, then information from the current
article is displayed. Successful responses start with a 224 article is displayed. Successful responses start with a 224
response followed by the overview information for all matched response followed by the overview information for all matched
messages. Once the output is complete, a period is sent on a messages. Once the output is complete, a period is sent on a
line by itself. If no argument is specified, the information line by itself. If no argument is specified, the information
for the current article is returned. A news group must have for the current article is returned. A news group must have
been selected earlier, else a 412 error response is returned. been selected earlier, else a 412 error response is returned.
If no articles are in the range specified, the server returns If no articles are in the range specified, the server returns
skipping to change at line 2465 skipping to change at line 2248
The content of any subsequent field is given by the response The content of any subsequent field is given by the response
to the LIST OVERVIEW.FMT command. A field may be empty (in to the LIST OVERVIEW.FMT command. A field may be empty (in
which case there will be two adjacent US-ASCII tabs, and a which case there will be two adjacent US-ASCII tabs, and a
sequence of trailing US-ASCII tabs may be omitted). Any sequence of trailing US-ASCII tabs may be omitted). Any
sequence of US-ASCII space or non-printing characters in a sequence of US-ASCII space or non-printing characters in a
field MUST be replaced by a single US-ASCII space. field MUST be replaced by a single US-ASCII space.
The server SHOULD not produce output for articles that no The server SHOULD not produce output for articles that no
longer exist. longer exist.
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9.5.2.2.1 Responses 9.5.2.2.1 Responses
224 Overview information follows 224 Overview information follows
412 No news group current selected 412 No news group current selected
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420 No article(s) selected 420 No article(s) selected
500 Command not recognized 500 Command not recognized
502 Service Unavailable 502 Service Unavailable
9.5.2.2.2 Examples 9.5.2.2.2 Examples
Example of a successful retrieval of overview information for Example of a successful retrieval of overview information for
an article (using no article number) an article (using no article number)
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] OVER [C] OVER
[S] 224 Overview information follows [S] 224 Overview information follows
300234|I am just a test article|nobody@nowhere.to 300234|I am just a test article|nobody@nowhere.to
(Demo User)|6 Oct 1998 04:38:40 -0500| (Demo User)|6 Oct 1998 04:38:40 -0500|
<45223423@to.to> <45223423@to.to>
[S] . [S] .
[Please note that the line that begins with 300234 is all one [Please note that the line that begins with 300234 is all one
line that has been wrapped for readability. A vertical bar has line that has been wrapped for readability. A vertical bar has
been inserted to show where the US-ASCII TAB should actually been inserted to show where the US-ASCII TAB should actually
be.] be.]
Example of an unsuccessful retrieval of overview information Example of an unsuccessful retrieval of overview information
on an article by number on an article by number
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] OVER 300256 [C] OVER 300256
[S] 420 No such article in this group [S] 420 No such article in this group
Example of an unsuccessful retrieval of overview information Example of an unsuccessful retrieval of overview information
by number because no news group was selected first by number because no news group was selected first
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] OVER [C] OVER
[S] 412 No news group selected [S] 412 No news group selected
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Example of an attempt to retrieve an article when the current Example of an attempt to retrieve an article when the current
group selected is empty group selected is empty
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP example.empty.newsgroup [C] GROUP example.empty.newsgroup
[S] 211 0 0 0 example.empty.newsgroup [S] 211 0 0 0 example.empty.newsgroup
[C] OVER [C] OVER
[S] 420 No current article selected [S] 420 No current article selected
9.5.3 The PAT Extension 9.5.3 The PAT Extension
This extension provides one new command, PAT. The label for This extension provides one new command, PAT. The label for
this extension is PAT. this extension is PAT.
9.5.3.1 PAT 9.5.3.1 PAT
PAT header range|<message-id> [wildmat[ wildmat...]] PAT header range|<message-id> [wildmat]
The PAT command is used to retrieve specific headers from The PAT command is used to retrieve specific headers from
specific articles in the currently selected group, based on specific articles in the currently selected group, based on
pattern matching on the contents of the header. pattern matching on the contents of the header.
The required header parameter is the name of a header line The required header parameter is the name of a header line
(e.g. "subject") in a news group article. See RFC-1036 for a (e.g. "subject") in a news group article. See RFC-1036 for a
list of valid header lines. The required range argument may be list of valid header lines. The required range argument may be
any of the following: any of the following:
. an article number o an article number
. an article number followed by a dash to indicate all following o an article number followed by a dash to indicate all
. an article number followed by a dash followed by another following
o an article number followed by a dash followed by another
article number. article number.
The required message-id argument indicates a specific article. The required message-id argument indicates a specific article.
The range and message-id arguments are mutually exclusive. The range and message-id arguments are mutually exclusive.
Additional arguments consisting of one or more wildmats, Additional arguments consisting of one or more wildmats,
separated by an US-ASCII space, may be specified. The default separated by an US-ASCII space, may be specified. The default
is the single wildmat "*". is the single wildmat "*".
A successful response consists of a 221 code followed by the A successful response consists of a 221 code followed by the
output from the command. The output consists of one line for output from the command. The output consists of one line for
each article where the relevant header line matches one or each article where the relevant header line matches one or
more of the wildmats. The line consists of the article number, more of the wildmats. The line consists of the article number,
a US-ASCII space, and then the contents of the header (without a US-ASCII space, and then the contents of the header (without
the header name). A valid response includes an empty list the header name). A valid response includes an empty list
(indicating that there were no matches). Once the output is (indicating that there were no matches). Once the output is
complete, a period is sent on a line by itself. If the complete, a period is sent on a line by itself. If the
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optional argument is a message-id and no such article exists, optional argument is a message-id and no such article exists,
a 430 error response shall be returned. A 502 response shall a 430 error response shall be returned. A 502 response shall
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be returned if the client only has permission to transfer be returned if the client only has permission to transfer
articles. A 500 response SHOULD be issued by all servers that articles. A 500 response SHOULD be issued by all servers that
do not recognize this command. do not recognize this command.
9.5.3.1.1 Responses 9.5.3.1.1 Responses
221 Header follows 221 Header follows
412 no newsgroup selected 412 no newsgroup selected
430 no such article 430 no such article
500 Command not recognized 500 Command not recognized
skipping to change at line 2596 skipping to change at line 2375
430 no such article 430 no such article
500 Command not recognized 500 Command not recognized
502 Service Unavailable 502 Service Unavailable
9.5.3.1.2 Examples 9.5.3.1.2 Examples
Example of a successful retrieval of subject lines from a Example of a successful retrieval of subject lines from a
range of articles range of articles
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] PAT Subject 3000234-300238 [C] PAT Subject 3000234-300238
[S] 221 Header Follows [S] 221 Header Follows
[S] 3000234 I am just a test article [S] 3000234 I am just a test article
[S] 3000237 Re: I am just a test article [S] 3000237 Re: I am just a test article
[S] 3000238 Ditto [S] 3000238 Ditto
[S] . [S] .
Example of a successful retrieval of subject lines from a Example of a successful retrieval of subject lines from a
range of articles with header pattern matching range of articles with header pattern matching
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test [C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
[C] PAT Subject 3000234-300238 *j*
[C] PAT Subject 3000234-300238 j* ? *est
[S] 221 Header Follows [S] 221 Header Follows
[S] 3000234 I am just a test article [S] 3000234 I am just a test article
[S] 3000237 Re: I am just a test article [S] 3000237 Re: I am just a test article
[S] . [S] .
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Example of a successful retrieval of header from an article by Example of a successful retrieval of header from an article by
message-id message-id
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP misc.test
[S] 211 1234 3000234 3002322 misc.test
[C] PAT subject <i.am.a.test.article@nowhere.to> [C] PAT subject <i.am.a.test.article@nowhere.to>
[S] 221 Header information follows [S] 221 Header information follows
[S] 3000345 I am just a test article [S] 3000345 I am just a test article
[S] . [S] .
Example of an unsuccessful retrieval of a header from an Example of an unsuccessful retrieval of a header from an
article by message-id article by message-id
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] PAT subject <i.am.not.there@nowhere.to> [C] PAT subject <i.am.not.there@nowhere.to>
[S] 430 No Such Article Found [S] 430 No Such Article Found
Example of an unsuccessful retrieval of headers from articles Example of an unsuccessful retrieval of headers from articles
by number because no news group was selected first by number because no news group was selected first
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] PAT subject 300256- [C] PAT subject 300256-
[S] 412 No news group selected
Example of an unsuccessful retrieval of headers from articles
by message-id because no news group was selected first
[S] 200 NNTP Service Ready
[C] PAT subject <i.am.a.test.article@nowhere.to>
[S] 412 No news group selected [S] 412 No news group selected
Example of retrieving header information when the current Example of retrieving header information when the current
group selected is empty group selected is empty
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] GROUP example.empty.newsgroup [C] GROUP example.empty.newsgroup
[S] 211 0 0 0 example.empty.newsgroup [S] 211 0 0 0 example.empty.newsgroup
[C] PAT subject 0- [C] PAT subject 0-
[S] 221 Headers follow [S] 221 Headers follow
. .
Example of a failure due to restrictions configured into the Example of a failure due to restrictions configured into the
server server
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
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[C] GROUP news.group
[S] 211 1234 3000234 3002322 misc.test [S] 211 1234 3000234 3002322 misc.test
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[C] PAT Subject 3000234-300238 [C] PAT Subject 3000234-300238
[S] 502 Service Unavailable [S] 502 Service Unavailable
10. The CONCLUSION Step 10. The CONCLUSION Step
10.1 QUIT 10.1 QUIT
QUIT QUIT
The server process MUST acknowledge the QUIT command and then The server process MUST acknowledge the QUIT command and then
close the connection to the client. This is the preferred close the connection to the client. This is the preferred
skipping to change at line 2705 skipping to change at line 2470
10.1 QUIT 10.1 QUIT
QUIT QUIT
The server process MUST acknowledge the QUIT command and then The server process MUST acknowledge the QUIT command and then
close the connection to the client. This is the preferred close the connection to the client. This is the preferred
method for a client to indicate that it has finished all its method for a client to indicate that it has finished all its
transactions with the NNTP server. transactions with the NNTP server.
If a client simply disconnects (or the connection times out or If a client simply disconnects (or the connection times out or
some other fault occurs), the server SHALL gracefully cease some other fault occurs), the server MUST gracefully cease its
its attempts to service the client. attempts to service the client, disconnecting from its end if
necessary.
10.1.1 Responses 10.1.1 Responses
205 closing connection - goodbye! 205 closing connection - goodbye!
10.1.2 Example 10.1.2 Example
[S] 200 NNTP Service Ready
[S] 200 NNTP Service Ready
[C] QUIT [C] QUIT
[S] 205 closing connection [S] 205 closing connection
11. Other Keywords 11. Other Keywords
There are other keywords that may be used at any time between There are other keywords that may be used at any time between
the beginning of a session and its termination. Using these the beginning of a session and its termination. Using these
keywords does not alter any state information, but the keywords does not alter any state information, but the
response generated from the use of these keywords may provide response generated from the use of these keywords may provide
useful information to clients that use them. useful information to clients that use them.
skipping to change at line 2730 skipping to change at line 2495
There are other keywords that may be used at any time between There are other keywords that may be used at any time between
the beginning of a session and its termination. Using these the beginning of a session and its termination. Using these
keywords does not alter any state information, but the keywords does not alter any state information, but the
response generated from the use of these keywords may provide response generated from the use of these keywords may provide
useful information to clients that use them. useful information to clients that use them.
11.1 DATE 11.1 DATE
DATE DATE
This command exists to help clients find out the current time This command exists to help clients find out the current time
from the server's perspective. This command SHOULD NOT be from the server's perspective. This command SHOULD NOT be
used as a substitute for NTP[8], but to provide information
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used as a substitute for NTP[7], but to provide information
that might be useful when using the NEWNEWS command (see that might be useful when using the NEWNEWS command (see
section 11.5). section 11.4).
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This command returns a one-line response code of 111 followed This command returns a one-line response code of 111 followed
by the UTC (or GMT) date and time on the server in the form by the UTC (or GMT) date and time on the server in the form
YYYYMMDDhhmmss. YYYYMMDDhhmmss.
11.1.1 Responses 11.1.1 Responses
111 YYYYMMDDhhmmss 111 YYYYMMDDhhmmss
11.1.2 Example 11.1.2 Example
[S] 200 NNTP Service Ready
[S] 200 NNTP Service Ready
[C] DATE [C] DATE
[S] 111 19990623135624 [S] 111 19990623135624
11.2 The DEBUG Command 11.2 The HELP Command
DEBUG ON|OFF|ACK
The DEBUG command is available for implementers and system
administrators to use in debugging problems with a server.
A client sends the command DEBUG ON to activate the use of
debugging responses. The client sends the command DEBUG OFF
to deactivate the use of debugging responses. A client sends
the command DEBUG ACK acknowledge the presentation of a
DEBUG response code. Once a DEBUG ACK has been sent the
client should expect the server to respond with another
debugging result code or a response code appropriate to the
command sent that started the most recent protocol
transaction. Servers that recognize but are not configured
to permit the use of DEBUG commands will return a 502
command when the DEBUG command is used. Servers that do not
recognize the DEBUG command will return a 500 error code.
11.2.1 Responses
291 DEBUG ON Acknowledged
292 DEBUG OFF Acknowledged
500 Command not recognized
502 Service unavailable
11.2.2 Examples
An example of activating, running a command and then
deactivating the DEBUG responses [Different servers may have
different debug response codes in use for different commands.
This is just an example using code 191.]
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[S] 200 NNTP Service Ready
[C] DEBUG ON
[S] 291 DEBUG ON Acknowledged
[C] GROUP misc.test
[S] 191 Searching active file to see if group exists
[C] DEBUG ACK
[S] 211 1234 3000234 3002322 misc.test
[C] DEBUG OFF
[S] 292 DEBUG OFF Acknowledged
An example of a negative response to DEBUG ON [The server does
not disconnect after presenting the negative response.]
[S] 200 NNTP Service Ready
[C] DEBUG ON
[S] 502 Service unavailable
11.3 The HELP Command
HELP HELP
This command provides a short summary of commands that are This command provides a short summary of commands that are
understood by this implementation of the server. The help text understood by this implementation of the server. The help text
will be presented as a textual response terminated by a single will be presented as a textual response terminated by a single
period on a line by itself. period on a line by itself.
This text is not guaranteed to be in any particular format and This text is not guaranteed to be in any particular format and
SHALL NOT be used by clients as a replacement for the LIST SHALL NOT be used by clients as a replacement for the LIST
EXTENSIONS command described in section 8.1. EXTENSIONS command described in section 8.1.
11.3.1 Responses 11.2.1 Responses
100 help text follows 100 help text follows
11.3.2 Example 11.2.2 Example
[S] 200 NNTP Service Ready
[S] 200 NNTP Service Ready
[C] HELP [C] HELP
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[S] 100 Help text follows [S] 100 Help text follows
[S] This is some help text. There is no specific [S] This is some help text. There is no specific
[S] formatting requirement for this test, though [S] formatting requirement for this test, though
[S] it is customary for it to list the valid commands [S] it is customary for it to list the valid commands
[S] and give a brief definition of what they do [S] and give a brief definition of what they do
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[S] . [S] .
11.4 NEWGROUPS 11.3 NEWGROUPS
NEWGROUPS date time [GMT|UTC] NEWGROUPS date time [GMT|UTC]
A list of newsgroups created since <date and time> MUST be A list of newsgroups created since <date and time> MUST be
listed in the same format as the LIST command. listed in the same format as the LIST command.
The date is sent as 6 or 8 digits in the format [XX]YYMMDD, The date is sent as 6 or 8 digits in the format [XX]YYMMDD,
where XX is the first two digits of the year, YY is the last where XX is the first two digits of the year, YY is the last
two digits of the year, MM is the two digits of the month two digits of the year, MM is the two digits of the month
(with leading zero, if appropriate), and DD is the day of the (with leading zero, if appropriate), and DD is the day of the
skipping to change at line 2883 skipping to change at line 2588
of NNTP to establish the server's local timezone. of NNTP to establish the server's local timezone.
Note that an empty list (i.e., the text body returned by this Note that an empty list (i.e., the text body returned by this
command consists only of the terminating period) is a possible command consists only of the terminating period) is a possible
valid response, and indicates that there are currently no new valid response, and indicates that there are currently no new
newsgroups. newsgroups.
Clients SHOULD make all queries using GMT/UTC time when Clients SHOULD make all queries using GMT/UTC time when
possible. possible.
11.4.1 Responses 11.3.1 Responses
231 list of new newsgroups follows 231 list of new newsgroups follows
11.4.2 Examples 11.3.2 Examples
Example where there are new groups Example where there are new groups
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[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] NEWGROUPS 19990624 000000 UTC [C] NEWGROUPS 19990624 000000 UTC
[S] 230 list of new newsgroups follows [S] 230 list of new newsgroups follows
[S] alt.rfc-writers.recovery [S] alt.rfc-writers.recovery
[S] tx.natives.recovery [S] tx.natives.recovery
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[S] . [S] .
Example where there are no new groups Example where there are no new groups
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] NEWGROUPS 19990624 000000 UTC [C] NEWGROUPS 19990624 000000 UTC
[S] 230 list of new newsgroups follows [S] 230 list of new newsgroups follows
[S] . [S] .
11.5 NEWNEWS 11.4 NEWNEWS
NEWNEWS newsgroups date time [GMT] NEWNEWS newsgroups date time [GMT]
A list of message-ids of articles posted or received to the A list of message-ids of articles posted or received to the
specified news group or groups since "date" will be listed. specified news group or groups since "date" will be listed.
The format of the listing will be one message-id per line, as The format of the listing will be one message-id per line, as
though text were being sent. Each message-id SHALL appear only though text were being sent. Each message-id SHALL appear only
once in a response. The order of the response has no specific once in a response. The order of the response has no specific
significance and may vary from response to response in the significance and may vary from response to response in the
same session. A single line consisting solely of one period same session. A single line consisting solely of one period
skipping to change at line 2938 skipping to change at line 2641
consist of multiple wildmat constructs separated by an US- consist of multiple wildmat constructs separated by an US-
ASCII comma character. ASCII comma character.
Note that an empty list (i.e., the text body returned by this Note that an empty list (i.e., the text body returned by this
command consists only of the terminating period) is a possible command consists only of the terminating period) is a possible
valid response, and indicates that there is currently no new valid response, and indicates that there is currently no new
news. news.
Clients SHOULD make all queries in GMT/UTC time when possible. Clients SHOULD make all queries in GMT/UTC time when possible.
11.5.1 Responses 11.4.1 Responses
230 list of new articles by message-id follows 230 list of new articles by message-id follows
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11.5.2 Examples
Example where there are new articles Example where there are new articles
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] NEWNEWS news.*,sci.* 19990624 000000 [C] NEWNEWS news.*,sci.* 19990624 000000
[S] 230 list of new articles by message-id follows [S] 230 list of new articles by message-id follows
[S] <i.am.a.new.article@nowhere.to> [S] <i.am.a.new.article@nowhere.to>
[S] <i.am.another.new.article@nowhere.to> [S] <i.am.another.new.article@nowhere.to>
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Example where there are no new articles Example where there are no new articles
[S] 200 NNTP Service Ready [S] 200 NNTP Service Ready
[C] NEWNEWS alt.* 19990624 000000 [C] NEWNEWS alt.* 19990624 000000
[S] 230 list of new articles by message-id follows [S] 230 list of new articles by message-id follows
[S] . [S] .
12. Framework for NNTP Extensions 12. Framework for NNTP Extensions
Although NNTP is widely and robustly deployed, some parts of Although NNTP is widely and robustly deployed, some parts of
the Internet community might wish to extend the NNTP service. the Internet community might wish to extend the NNTP service.
This memo defines a means whereby an extended NNTP client may This memo defines a means whereby an extended NNTP client may
query the server to determine the service extensions that it query the server to determine the service extensions that it
supports. supports.
skipping to change at line 2995 skipping to change at line 2697
many cases, the cost of extending the NNTP service will likely many cases, the cost of extending the NNTP service will likely
outweigh the benefit. outweigh the benefit.
Given this environment, the framework for the extensions Given this environment, the framework for the extensions
described in this memo consists of: described in this memo consists of:
a) a mechanism for clients to determine a server's available a) a mechanism for clients to determine a server's available
extensions extensions
b) a registry of NNTP service extensions b) a registry of NNTP service extensions
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The LIST EXTENSIONS command is described in section 8.1 of The LIST EXTENSIONS command is described in section 8.1 of
this memo and is the mechanism for clients to use to determine this memo and is the mechanism for clients to use to determine
what extensions are available for client use. what extensions are available for client use.
The IANA shall maintain a registry of NNTP service extensions. The IANA shall maintain a registry of NNTP service extensions.
Associated with each such extension is a corresponding NNTP An extension is identified by an unique extension-label, which
keyword value. Each service extension registered with the IANA is an string of 1 to 12 uppercase letters. The extension-label
MUST be defined in an RFC. Such RFCs either must be on the will often be the name of a new command that the extension
standards-track or must define an IESG-approved experimental adds. However this is not a requirement: an extension might
protocol. The definition must include: not add any new commands or keywords.
. the textual name of the NNTP service extension Barber [Page 53]
. the label that is returned by LIST EXTENSIONS that would
indicate to the client that the server supports this
particular extension
. any new NNTP keywords associated with the extension
. the syntax and possible values of parameters associated with
the new NNTP keywords
. any new parameters the extension associates with any other
pre-existing NNTP keywords
. how support for the extension affects the behavior of a server
and client NNTP
. any increase in the maximum length of commands over the value
specified in this memo
In addition, any NNTP keyword value that starts with an upper INTERNET DRAFT S. Barber
or lower case "X" refers to a local NNTP service extension, Expires: May 30, 2001 Academ Consulting Services
which is used through bilateral, rather than standardized, October 2000
agreement. Keywords beginning with "X" MUST NOT be used in a An extension is either a private extension or else it is
registered service extension. included in the IANA registry and is defined in an RFC. Such
RFCs either must be on the standards-track or must define an
IESG-approved experimental protocol.
The definition of an extension must include:
o a descriptive name for the extension
o the extension-label (which is returned by LIST EXTENSIONS
to
o indicate to the client that the server supports this
particular extension)
o the syntax, values, and meanings of any parameters
following the extension-label in the output of LIST
EXTENSIONS
o any new NNTP keywords associated with the extension
o the syntax and possible values of parameters associated
with the new NNTP keywords
o any new parameters the extension associates with any
other pre-existing NNTP keywords
o how support for the extension affects the behavior of a
server and client NNTP
o any increase in the maximum length of commands over the
value specified in this memo
The extension-label of private extensions MUST begin with "X".
The extension-label of registered extensions MUST NOT begin
with "X".
Any keyword values presented in the NNTP response that do not Any keyword values presented in the NNTP response that do not
begin with "X" must correspond to a standard, standards-track, begin with "X" MUST correspond to a standard, standards-track,
or IESG-approved experimental NNTP service extension or IESG-approved experimental NNTP service extension
registered with IANA. A conforming server MUST NOT offer non registered with IANA. A conforming server MUST NOT offer non
"X" prefixed keyword values that are not described in a "X" prefixed keyword values that are not described in a
registered extension. registered extension.
Additional keywords are bound by the same rules as NNTP Except where stated otherwise, the commands in this document
keywords; specifically, keywords beginning with "X" are local are understood (even if not supported) by all servers and are
extensions that MUST NOT be registered or standardized and not described in the list of features returned by the LIST
keywords not beginning with "X" must always be registered. EXTENSIONS command.
A server MAY provide additional keywords - either new commands
or new parameters to existing commands - as part of a private
extension. These new keywords MUST begin with "X".
A server MUST NOT send different response codes to basic NNTP
commands documented here or commands documented in registered
extensions in response to the availability or use of a private
extension.
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12.1 Initial IANA Registry 12.1 Initial IANA Registry
The IANA's initial registry of NNTP service extensions The IANA's initial registry of NNTP service extensions
consists of these entries: consists of these entries:
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Service Extension NNTP Extension Label Added Behavior Service Extension NNTP Extension Label Added Behavior
----------------- -------------------- ---------------
Overview Support OVER Defined in this Overview Support OVER Defined in this
document document
Specific Article LISTGROUP Defined in this Specific Article LISTGROUP Defined in this
Numbers document Numbers document
Header Pattern PAT Defined in this Header Pattern PAT Defined in this
Matching document Matching document
13. Augmented BNF[9] Syntax for NNTP Commands 13. Augmented BNF[8] Syntax for NNTP Commands
This syntax defines the non-terminal "command". The non-terminal This syntax defines the non-terminal "command". The non-terminal
"parameter" is used for command parameters whose syntax is "parameter" is used for command parameters whose syntax is
specified elsewhere. The syntax is in alphabetical order. Note specified elsewhere. The syntax is in alphabetical order. Note
that ABNF strings are case insensitive. that ABNF strings are case insensitive.
article-command = "ARTICLE" [1*WSP (msg-id / article-number)] article-command = "ARTICLE" [1*WSP (msg-id / article-number)]
*WSP CRLF *WSP CRLF
article-number = 1*16DIGIT article-number = 1*16DIGIT
augument = parameter ; excluding sequence ".." argument = parameter ; excluding sequence ".."
body-command = "BODY" [1*WSP (msg-id / article-number)] *WSP body-command = "BODY" [1*WSP (msg-id / article-number)] *WSP
CRLF CRLF
command = article-command / command = article-command /
body-command / body-command /
debug-command /
date-command / date-command /
group-command / group-command /
head-command / head-command /
help-command / help-command /
ihave-command / ihave-command /
last-command / last-command /
list-active-times-command / list-active-times-command /
list-distrib-pats-command / list-distrib-pats-command /
list-distributions-command / list-distributions-command /
list-extensions-command / list-extensions-command /
list-newsgroups-command / list-newsgroups-command /
list-overview-fmt-command / list-overview-fmt-command /
list-command / list-command /
listgroup-command / listgroup-command /
mode-reader-command / mode-reader-command /
newgroups-command / newgroups-command /
newnews-command / newnews-command /
next-command / next-command /
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over-command / over-command /
pat-command / pat-command /
post-command / post-command /
quit-command / quit-command /
stat-command stat-command
CR = %x0D CR = %x0D
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CRLF = CR LF CRLF = CR LF
date-command = "DATE" *WSP CRLF date-command = "DATE" *WSP CRLF
date = 6*8DIGIT date = 6*8DIGIT
DIGIT = %x30-39 DIGIT = %x30-39
debug-command = "DEBUG" 1*WSP ("ON"/"OFF"/"ACK") *WSP CRLF
group-command = "GROUP" 1*WSP newsgroup *WSP CRLF group-command = "GROUP" 1*WSP newsgroup *WSP CRLF
head-command = "HEAD" [1*WSP (msg-id / article-number)] *WSP head-command = "HEAD" [1*WSP (msg-id / article-number)] *WSP
CRLF CRLF
header = parameter header = parameter
help-command = "HELP" *WSP CRLF help-command = "HELP" *WSP CRLF
HT = %x09 HT = %x09
ihave-command = "IHAVE" 1*WSP msg-id *WSP CRLF ihave-command = "IHAVE" 1*WSP msg-id *WSP CRLF
last-command = "LAST" *WSP CRLF last-command = "LAST" *WSP CRLF
LF = %x0A LF = %x0A
list-active-times-command = "LIST" 1*WSP "ACTIVE.TIMES" list-active-times-command = "LIST" 1*WSP "ACTIVE.TIMES"
skipping to change at line 3141 skipping to change at line 2870
"GMT"/"UTC"] *WSP CRLF "GMT"/"UTC"] *WSP CRLF
newnews-command = "NEWNEWS" 1*WSP newsgroup *("," newsgroup) newnews-command = "NEWNEWS" 1*WSP newsgroup *("," newsgroup)
1*WSP date 1*WSP time [1*WSP "GMT"/"UTC"] 1*WSP date 1*WSP time [1*WSP "GMT"/"UTC"]
*WSP CRLF *WSP CRLF
newsgroup = parameter newsgroup = parameter
next-command = "NEXT" *WSP CRLF next-command = "NEXT" *WSP CRLF
over-command = "OVER" [1*WSP range] *WSP CRLF over-command = "OVER" [1*WSP range] *WSP CRLF
parameter = 1*(%x21-FF) ; generic command parameter parameter = 1*(%x21-FF) ; generic command parameter
pat-command = "PAT" 1*WSP header 1*WSP (range / msg-id) pat-command = "PAT" 1*WSP header 1*WSP (range / msg-id)
*(1*WSP wildmat) *WSP CRLF *(1*WSP wildmat) *WSP CRLF
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post-command = "POST" *WSP CRLF post-command = "POST" *WSP CRLF
quit-command = "QUIT" *WSP CRLF quit-command = "QUIT" *WSP CRLF
range = article-number ["-" [article-number]] range = article-number ["-" [article-number]]
SP = %x20 SP = %x20
stat-command = "STAT" [1*WSP (msg-id / article-number)] *WSP stat-command = "STAT" [1*WSP (msg-id / article-number)] *WSP
CRLF CRLF
time = 6DIGIT time = 6DIGIT
UTF-8-non-ascii = UTF8-2 / UTF8-3 / UTF8-4 / UTF8-5 / UTF8-6 UTF-8-non-ascii = UTF8-2 / UTF8-3 / UTF8-4 / UTF8-5 / UTF8-6
UTF8-1 = %x80-BF UTF8-1 = %x80-BF
UTF8-2 = %xC0-DF UTF8-1 UTF8-2 = %xC0-DF UTF8-1
UTF8-3 = %xE0-EF 2UTF8-1 UTF8-3 = %xE0-EF 2UTF8-1
UTF8-4 = %xF0-F7 3UTF8-1 UTF8-4 = %xF0-F7 3UTF8-1
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UTF8-5 = %xF8-FB 4UTF8-1 UTF8-5 = %xF8-FB 4UTF8-1
UTF8-6 = %xFC-FD 5UTF8-1 UTF8-6 = %xFC-FD 5UTF8-1
wildmat = ["!"]1*("*" / "?" / wildmat-exact / wildmat-set / wildmat = ["!"]1*("*" / "?" / wildmat-exact / wildmat-set /
"\" (%x22-7F / UTF-8-non-ascii)) "\" (%x22-7F / UTF-8-non-ascii))
wildmat-exact = %x22-29 / %x2B-3E / %x40-5A / %x5D-7F / UTF-8- wildmat-exact = %x22-29 / %x2B-3E / %x40-5A / %x5D-7F / UTF-8-
non-ascii ; exclude space ! * ? [ \ non-ascii ; exclude space ! * ? [ \
wildmat-non-hyphen = %x21-2C / %x2E-7F / UTF-8-non-ascii ; wildmat-non-hyphen = %x21-2C / %x2E-7F / UTF-8-non-ascii ;
exclude space - exclude space -
wildmat-set = "[" ["^"] ["]" / "-"] *(wildmat-non-hyphen"["-" wildmat-set = "[" ["^"] ["]" / "-"] *(wildmat-non-hyphen"["-"
wildmat-non-hyphen]) ["-"] wildmat-non-hyphen]) ["-"]
skipping to change at line 3191 skipping to change at line 2924
and/or proprietary information is available in some of those and/or proprietary information is available in some of those
articles. It is very important that designers and implementers articles. It is very important that designers and implementers
provide informative warnings to users so personal and/or provide informative warnings to users so personal and/or
proprietary information is not disclosed inadvertently. proprietary information is not disclosed inadvertently.
Additionally, effective and easily understood mechanisms to Additionally, effective and easily understood mechanisms to
manage the distribution of news articles must be provided to manage the distribution of news articles must be provided to
NNTP Server administrators, so that they are able to report NNTP Server administrators, so that they are able to report
with confidence what information is and is not being forwarded with confidence what information is and is not being forwarded
in news articles passing though their servers. in news articles passing though their servers.
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14.2 Abuse of Server Log Information 14.2 Abuse of Server Log Information
A server is in the position to save session data about a A server is in the position to save session data about a
user's requests that might identify their reading patterns or user's requests that might identify their reading patterns or
subjects of interest. This information is clearly confidential subjects of interest. This information is clearly confidential
in nature and its handling can be constrained by law in in nature and its handling can be constrained by law in
certain countries. People using the NNTP protocol to provide certain countries. People using the NNTP protocol to provide
data are responsible for ensuring that such material is not data are responsible for ensuring that such material is not
distributed without the permission of any individuals that are distributed without the permission of any individuals that are
identifiable by the published results. identifiable by the published results.
14.3 DNS Spoofing 14.3 DNS Spoofing
Clients and Servers using NNTP rely heavily on the Domain Name Clients and Servers using NNTP rely heavily on the Domain Name
Service, and are thus generally prone to security attacks Service, and are thus generally prone to security attacks
based on the deliberate mis-association of IP addresses and based on the deliberate misassociation of IP addresses and DNS
DNS names. Clients and Servers need to be cautious in assuming names. Clients and Servers need to be cautious in assuming the
the continuing validity of an IP number/DNS name association. continuing validity of an IP number/DNS name association.
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In particular, NNTP clients and servers SHOULD rely on their In particular, NNTP clients and servers SHOULD rely on their
name resolver for confirmation of an IP number/DNS name name resolver for confirmation of an IP number/DNS name
association, rather than caching the result of previous host association, rather than caching the result of previous host
name lookups. Many platforms already can cache host name name lookups. Many platforms already can cache host name
lookups locally when appropriate, and they SHOULD be lookups locally when appropriate, and they SHOULD be
configured to do so. It is proper for these lookups to be configured to do so. It is proper for these lookups to be
cached, however, only when the TTL (Time To Live) information cached, however, only when the TTL (Time To Live) information
reported by the name server makes it likely that the cached reported by the name server makes it likely that the cached
information will remain useful. information will remain useful.
skipping to change at line 3239 skipping to change at line 2976
will grow. Observing this requirement thus reduces this will grow. Observing this requirement thus reduces this
potential security vulnerability. potential security vulnerability.
This requirement also improves the load-balancing behavior of This requirement also improves the load-balancing behavior of
clients for replicated servers using the same DNS name and clients for replicated servers using the same DNS name and
reduces the likelihood of a user's experiencing failure in reduces the likelihood of a user's experiencing failure in
accessing sites which use that strategy. accessing sites which use that strategy.
14.4 Weak Authentication and Access Control 14.4 Weak Authentication and Access Control
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There is no user-based or token-based authentication in the There is no user-based or token-based authentication in the
basic NNTP specification. Access is normally controlled by basic NNTP specification. Access is normally controlled by
server configuration files. Those files specify access by server configuration files. Those files specify access by
using domain names or IP addresses. However, this using domain names or IP addresses. However, this
specification does permit the creation of extensions to the specification does permit the creation of extensions to the
NNTP protocol itself for such purposes. While including such NNTP protocol itself for such purposes. While including such
mechanisms is optional, doing so is strongly encouraged. mechanisms is optional, doing so is strongly encouraged.
Other mechanisms are also available. For example, a proxy Other mechanisms are also available. For example, a proxy
server could be put in place that requires authentication server could be put in place that requires authentication
before connecting via the proxy to the NNTP server. before connecting via the proxy to the NNTP server.
15. References 15. References
[1] Kantor, B and P. Lapsley, "Network News Transfer Protocol", [1] Kantor, B and P. Lapsley, "Network News Transfer Protocol",
RFC-977, U.C. San Diego and U.C. Berkeley. RFC-977, U.C. San Diego and U.C. Berkeley.
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[2] Yergeau, F., "UTF-8, a transformation format of ISO 10646", [2] Yergeau, F., "UTF-8, a transformation format of ISO 10646",
RFC 2279, Alis Technologies. RFC 2279, Alis Technologies.
[3] Coded Character Set-7-bit American Standard Code for [3] Coded Character Set-7-bit American Standard Code for
Information Interchange, ANSI x3.4-1986. Information Interchange, ANSI x3.4-1986.
[4] Bradner, Scott, "Key words for use in RFCs to Indicate [4] Bradner, Scott, "Key words for use in RFCs to Indicate
Requirement Levels", RFC-2119, Harvard University. Requirement Levels", RFC-2119, Harvard University.
[5] Salz, Rich, Manual Page for wildmat(3) from the INN 1.4 [5] Salz, Rich, Manual Page for wildmat(3) from the INN 1.4
distribution, UUNET Technologies, Revision 1.10, April, 1992. distribution, UUNET Technologies, Revision 1.10, April, 1992.
[6] Robertson, Rob, "FAQ: Overview database / NOV General
[6] Horton, M.R. and R. Adams, "Standard for interchange of
USENET messages", RFC-1036, AT&T Bell Laboratories and Center
for Seismic Studies, December, 1987.
[7] Robertson, Rob, "FAQ: Overview database / NOV General
Information", ftp://ftp.uu.net/networking/news/nntp/inn/faq- Information", ftp://ftp.uu.net/networking/news/nntp/inn/faq-
nov.Z, January, 1995. nov.Z, January, 1995.
[7] Mills, David L., "Network Time Protocol (Version 3),
[8] Mills, David L., "Network Time Protocol (Version 3),
Specification, Implementation and Analysis", RFC-1305, Specification, Implementation and Analysis", RFC-1305,
University of Delaware, March 1992. University of Delaware, March 1992.
[8] Crocker, D. and Overell, P., "Augmented BNF for Syntax
[9] Crocker, D. and Overell, P., "Augmented BNF for Syntax
Specifications: ABNF", RFC-2234, Internet Mail Consortium and Specifications: ABNF", RFC-2234, Internet Mail Consortium and
Demon Internet, Ltd. Demon Internet, Ltd.
16. Notes 16. Notes
UNIX is a registered trademark of the X/Open Consortium. UNIX is a registered trademark of the X/Open Consortium.
17. Acknowledgments 17. Acknowledgments
The author acknowledges the original authors of NNTP as The author acknowledges the original authors of NNTP as
skipping to change at line 3293 skipping to change at line 3023
Demon Internet, Ltd. Demon Internet, Ltd.
16. Notes 16. Notes
UNIX is a registered trademark of the X/Open Consortium. UNIX is a registered trademark of the X/Open Consortium.
17. Acknowledgments 17. Acknowledgments
The author acknowledges the original authors of NNTP as The author acknowledges the original authors of NNTP as
documented in RFC 977: Brian Kantor and Phil Lapsey. documented in RFC 977: Brian Kantor and Phil Lapsey.
The author gratefully acknowledges the work of the NNTP The author gratefully acknowledges the work of the NNTP
committee chaired by Eliot Lear. The organization of this committee chaired by Eliot Lear. The organization of this
document was influenced by the last available draft from this document was influenced by the last available draft from this
working group. A special thanks to Eliot for generously working group. A special thanks to Eliot for generously
providing the original machine readable sources for that providing the original machine readable sources for that
document. document.
Barber [Page 59]
INTERNET DRAFT S. Barber
Expires: May 30, 2001 Academ Consulting Services
October 2000
The author gratefully acknowledges the work of the Marshall The author gratefully acknowledges the work of the Marshall
Rose & John G. Meyers in RFC 1939 and the work of the DRUMS Rose & John G. Meyers in RFC 1939 and the work of the DRUMS
working group, specifically RFC 1869, which is the basis of working group, specifically RFC 1869, which is the basis of
the NNTP extensions mechanism detailed in this document. the NNTP extensions mechanism detailed in this document.
Barber [Page 63]
The author gratefully acknowledges the authors of RFC 2616 for The author gratefully acknowledges the authors of RFC 2616 for
providing specific and relevant examples of security issues providing specific and relevant examples of security issues
that should be considered for HTTP. Since many of the same that should be considered for HTTP. Since many of the same
considerations exist for NNTP, those examples that are considerations exist for NNTP, those examples that are
relevant have been included here with some minor rewrites. relevant have been included here with some minor rewrites.
The author gratefully acknowledges the comments and additional The author gratefully acknowledges the comments and additional
information provided by the following individuals in preparing information provided by the following individuals in preparing
one of the progenitors of this document: one of the progenitors of this document:
. Wayne Davison <davison@armory.com> o Wayne Davison <davison@armory.com>
. Clive D.W. Feather <clive@demon.net> o Clive D.W. Feather <clive@demon.net>
. Chris Lewis <clewis@bnr.ca> o Chris Lewis <clewis@bnr.ca>
. Tom Limoncelli <tal@mars.superlink.net> o Tom Limoncelli <tal@mars.superlink.net>
. Eric Schnoebelen <eric@egsner.cirr.com> o Eric Schnoebelen <eric@egsner.cirr.com>
. Rich Salz <rsalz@osf.org> o Rich Salz <rsalz@osf.org>
This work was motivated by the work of various newsreader This work was motivated by the work of various newsreader
authors and newsserver authors, which includes those listed authors and newsserver authors, which includes those listed
below: below:
. Rick Adams -- Original author of the NNTP extensions to the RN o Rick Adams-Original author of the NNTP extensions to the
newsreader and last maintainer of Bnews RN newsreader and last maintainer of Bnews
. Stan Barber -- Original author of the NNTP extensions to the o Stan Barber-Original author of the NNTP extensions to the
newsreaders that are part of Bnews. newsreaders that are part of Bnews.
. Geoff Collyer -- Original author of the OVERVIEW database o Geoff Collyer-Original author of the OVERVIEW database
proposal and one of the original authors of CNEWS proposal and one of the original authors of CNEWS
. Dan Curry -- Original author of the xvnews newsreader o Dan Curry-Original author of the xvnews newsreader
. Wayne Davision -- Author of the first threading extensions to the o Wayne Davison-Author of the first threading extensions to
RN newsreader (commonly called TRN). the RN newsreader (commonly called TRN).
. Geoff Huston -- Original author of ANU NEWS o Geoff Huston-Original author of ANU NEWS
. Phil Lapsey -- Original author of the UNIX reference o Phil Lapsey-Original author of the UNIX reference
implementation implementation for NNTP
. Ian Lea -- Maintainer of the TIN newsreader o Iain Lea-Original maintainer of the TIN newsreader
. Chris Lewis -- First known implementor of the AUTHINFO GENERIC o Chris Lewis-First known implementor of the AUTHINFO
extension GENERIC extension
. Rich Salz -- Original author of INN o Rich Salz-Original author of INN
. Henry Spencer -- One of the original authors of CNEWS o Henry Spencer-One of the original authors of CNEWS
. Kim Storm -- Original author of the NN newsreader o Kim Storm-Original author of the NN newsreader
18. Author's Address 18. Author's Address
Stan Barber Stan Barber
P.O. Box 300481 P.O. Box 300481
Houston, Texas 77230 Houston, Texas 77230
Email: <sob@academ.com> Email: <sob@academ.com>
Barber [Page 64] This document expires May 30, 2001.
This document expires January 15, 2001.
Barber [Page 65] Barber [Page 60]
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