▼ |  | Net: Racket Networking Libraries

1 | URLs and HTTP
2 | URI Codec: Encoding and Decoding URIs
3 | Web Socket
4 | FTP: Client Downloading
5 | Send URL: Opening a Web Browser
6 | SMTP: Sending E-Mail
7 | sendmail: Sending E-Mail
8 | Headers: Parsing and Constructing
9 | IMAP: Reading Mail
10 | POP3: Reading Mail
11 | MIME: Decoding Internet Data
12 | Base 64: Encoding and Decoding
13 | Quoted-Printable: Encoding and Decoding
14 | DNS: Domain Name Service Queries
15 | NNTP: Newsgroup Protocol
16 | TCP: Unit and Signature
17 | TCP Redirect: tcp^ via Channels
18 | SSL Unit: tcp^ via SSL
19 | CGI Scripts
20 | Cookie: HTTP Client Storage
| Bibliography
| Index

► | 15 | NNTP: Newsgroup Protocol

15.1 | Connection and Operations
15.2 | Exceptions
15.3 | NNTP Unit
15.4 | NNTP Signature

On this page:

15.1`` Connection and Operations
communicator
connect-to-server
disconnect-from-server
open-news-group
authenticate-user
head-of-message
body-of-message
newnews-since
generic-message-command
make-desired-header
extract-desired-headers
15.2`` Exceptions
nntp
unexpected-response
bad-status-line
premature-close
bad-newsgroup-line
non-existent-group
article-not-in-group
no-group-selected
article-not-found
authentication-rejected
15.3`` NNTP Unit
nntp@
15.4`` NNTP Signature
nntp^

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### 15`` NNTP: Newsgroup Protocol

( require net/nntp )

The net/nntp module provides tools to access Usenet group via NNTP [RFC977].

#### 15.1`` Connection and Operations

( struct |  | communicator (sender receiver server port)
|  | #:extra-constructor-name make-communicator )

sender : output-port?
receiver : input-port?
server : string?
port : ( integer-in 0 65535)

Once a connection to a Usenet server has been established, its state is stored in a communicator, and other procedures take communicators as an argument.

( connect-to-server server [port-number]) → communicator?
server : string?
port-number : ( integer-in 0 65535) = 119

Connects to server at port-number.

( disconnect-from-server communicator) → void?
communicator : communicator?

Disconnects an NNTP communicator.

( open-news-group communicator newsgroup)

→

exact-nonnegative-integer?
exact-nonnegative-integer?
exact-nonnegative-integer?

communicator : communicator?
newsgroup : string?

Selects the newsgroup of an NNTP connection. The returned values are the total number of articles in the group, the first available article, and the last available article.

( authenticate-user |  | communicator |  |  |  |
|  | username |  |  |  |
|  | password) |  | → |  | void?

communicator : communicator?
username : string?
password : string?

Tries to authenticate a user with the original authinfo command (uses cleartext). The password argument is ignored if the server does not ask for it.

( head-of-message |  | communicator |  |  |  |
|  | message-index) |  | → |  | ( listof string? )

communicator : communicator?
message-index : exact-nonnegative-integer?

Given a message number, returns its header lines.

( body-of-message |  | communicator |  |  |  |
|  | message-index) |  | → |  | ( listof string? )

communicator : communicator?
message-index : exact-nonnegative-integer?

Given a message number, returns the body of the message.

( newnews-since communicator message-index) → ( listof string? )
communicator : communicator?
message-index : exact-nonnegative-integer?

Implements the NEWNEWS command (often disabled on servers).

(( generic-message-command |  | command |  |  |  |
|  | ok-code) |  |  |  |
|  | communicator |  |  |  |
|  | message-index) |  | → |  | ( listof string? )

command : string?
ok-code : exact-integer?
communicator : communicator?
message-index : exact-nonnegative-integer?

Useful primitive for implementing head-of-message, body-of-message and other similar commands.

( make-desired-header tag-string) → regexp?
tag-string : string?

Takes a header field’s tag and returns a regexp to match the field

( extract-desired-headers header desireds) → ( listof string? )
header : ( listof string? )
desireds : ( listof regexp? )

Given a list of header lines and of desired regexps, returns the header lines that match any of the desireds.

#### 15.2`` Exceptions

( struct |  | nntp exn ()
|  | #:extra-constructor-name make-nntp )

The supertype of all NNTP exceptions.

( struct |  | unexpected-response nntp (code text)
|  | #:extra-constructor-name make-unexpected-response )

code : exact-integer?
text : string?

Raised whenever an unexpected response code is received. The text field holds the response text sent by the server.

( struct |  | bad-status-line nntp (line)
|  | #:extra-constructor-name make-bad-status-line )

line : string?

Raised for mal-formed status lines.

( struct |  | premature-close nntp (communicator)
|  | #:extra-constructor-name make-premature-close )

communicator : communicator?

Raised when a remote server closes its connection unexpectedly.

( struct |  | bad-newsgroup-line nntp (line)
|  | #:extra-constructor-name make-bad-newsgroup-line )

line : string?

Raised when the newsgroup line is improperly formatted.

( struct |  | non-existent-group nntp (group)
|  | #:extra-constructor-name make-non-existent-group )

group : string?

Raised when the server does not recognize the name of the requested group.

( struct |  | article-not-in-group nntp (article)
|  | #:extra-constructor-name make-article-not-in-group )

article : exact-integer?

Raised when an article is outside the server’s range for that group.

( struct |  | no-group-selected nntp ()
|  | #:extra-constructor-name make-no-group-selected )

Raised when an article operation is used before a group has been selected.

( struct |  | article-not-found nntp (article)
|  | #:extra-constructor-name make-article-not-found )

article : exact-integer?

Raised when the server is unable to locate the article.

( struct |  | authentication-rejected nntp ()
|  | #:extra-constructor-name make-authentication-rejected )

Raised when the server reject an authentication attempt.

#### 15.3`` NNTP Unit

( require net/nntp-unit )

nntp@ : unit?

Imports nothing, exports nntp^.

#### 15.4`` NNTP Signature

( require net/nntp-sig )

nntp^ : signature

Includes everything exported by the net/nntp module.

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