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Net::NNTP(3) |
User Contributed Perl Documentation |
Net::NNTP(3) |
Net::NNTP - NNTP Client class
use Net::NNTP;
$nntp = Net::NNTP->new("some.host.name");
$nntp->quit;
# start with SSL, e.g. nntps
$nntp = Net::NNTP->new("some.host.name", SSL => 1);
# start with plain and upgrade to SSL
$nntp = Net::NNTP->new("some.host.name");
$nntp->starttls;
"Net::NNTP" is a class implementing a simple
NNTP client in Perl as described in RFC977 and RFC4642. With IO::Socket::SSL
installed it also provides support for implicit and explicit TLS encryption,
i.e. NNTPS or NNTP+STARTTLS.
The Net::NNTP class is a subclass of Net::Cmd and (depending on
avaibility) of IO::Socket::IP, IO::Socket::INET6 or IO::Socket::INET.
- "new([$host][, %options])"
- This is the constructor for a new Net::NNTP object.
$host is the name of the remote host to which a
NNTP connection is required. If not given then it may be passed as the
"Host" option described below. If no
host is passed then two environment variables are checked, first
"NNTPSERVER" then
"NEWSHOST", then
"Net::Config" is checked, and if a host
is not found then "news" is used.
%options are passed in a hash like
fashion, using key and value pairs. Possible options are:
Host - NNTP host to connect to. It may be a single
scalar, as defined for the "PeerAddr"
option in IO::Socket::INET, or a reference to an array with hosts to try
in turn. The "host" method will return the value which was
used to connect to the host.
Port - port to connect to. Default - 119 for plain NNTP
and 563 for immediate SSL (nntps).
SSL - If the connection should be done from start with
SSL, contrary to later upgrade with
"starttls". You can use SSL arguments
as documented in IO::Socket::SSL, but it will usually use the right
arguments already.
Timeout - Maximum time, in seconds, to wait for a
response from the NNTP server, a value of zero will cause all IO
operations to block. (default: 120)
Debug - Enable the printing of debugging information to
STDERR
Reader - If the remote server is INN then initially the
connection will be to innd, by default
"Net::NNTP" will issue a
"MODE READER" command so that the
remote server becomes nnrpd. If the
"Reader" option is given with a value
of zero, then this command will not be sent and the connection will be
left talking to innd.
LocalAddr and LocalPort - These parameters are
passed directly to IO::Socket to allow binding the socket to a specific
local address and port.
Domain - This parameter is passed directly to
IO::Socket and makes it possible to enforce IPv4 connections even if
IO::Socket::IP is used as super class. Alternatively Family can
be used.
Unless otherwise stated all methods return either a true or false
value, with true meaning that the operation was a success. When a
method states that it returns a value, failure will be returned as
undef or an empty list.
"Net::NNTP" inherits from
"Net::Cmd" so methods defined in
"Net::Cmd" may be used to send commands to
the remote NNTP server in addition to the methods documented here.
- "host()"
- Returns the value used by the constructor, and passed to IO::Socket::INET,
to connect to the host.
- "starttls()"
- Upgrade existing plain connection to SSL. Any arguments necessary for SSL
must be given in "new" already.
- "article([{$msgid|$msgnum}[, $fh]])"
- Retrieve the header, a blank line, then the body (text) of the specified
article.
If $fh is specified then it is
expected to be a valid filehandle and the result will be printed to it,
on success a true value will be returned. If $fh
is not specified then the return value, on success, will be a reference
to an array containing the article requested, each entry in the array
will contain one line of the article.
If no arguments are passed then the current article in the
currently selected newsgroup is fetched.
$msgnum is a numeric id of an article
in the current newsgroup, and will change the current article pointer.
$msgid is the message id of an article as shown
in that article's header. It is anticipated that the client will obtain
the $msgid from a list provided by the
"newnews" command, from references
contained within another article, or from the message-id provided in the
response to some other commands.
If there is an error then
"undef" will be returned.
- "body([{$msgid|$msgnum}[, [$fh]])"
- Like "article" but only fetches the body
of the article.
- "head([{$msgid|$msgnum}[, [$fh]])"
- Like "article" but only fetches the
headers for the article.
- "articlefh([{$msgid|$msgnum}])"
- "bodyfh([{$msgid|$msgnum}])"
- "headfh([{$msgid|$msgnum}])"
- These are similar to article(), body() and head(),
but rather than returning the requested data directly, they return a tied
filehandle from which to read the article.
- "nntpstat([{$msgid|$msgnum}])"
- The "nntpstat" command is similar to the
"article" command except that no text is
returned. When selecting by message number within a group, the
"nntpstat" command serves to set the
"current article pointer" without sending text.
Using the "nntpstat" command
to select by message-id is valid but of questionable value, since a
selection by message-id does not alter the "current article
pointer".
Returns the message-id of the "current article".
- "group([$group])"
- Set and/or get the current group. If $group is not
given then information is returned on the current group.
In a scalar context it returns the group name.
In an array context the return value is a list containing, the
number of articles in the group, the number of the first article, the
number of the last article and the group name.
- "help()"
- Request help text (a short summary of commands that are understood by this
implementation) from the server. Returns the text or undef upon
failure.
- "ihave($msgid[, $message])"
- The "ihave" command informs the server
that the client has an article whose id is $msgid.
If the server desires a copy of that article and
$message has been given then it will be sent.
Returns true if the server desires the article and
$message was successfully sent, if
specified.
If $message is not specified then the
message must be sent using the
"datasend" and
"dataend" methods from Net::Cmd
$message can be either an array of
lines or a reference to an array and must be encoded by the caller to
octets of whatever encoding is required, e.g. by using the Encode
module's "encode()" function.
- "last()"
- Set the "current article pointer" to the previous article in the
current newsgroup.
Returns the message-id of the article.
- "date()"
- Returns the date on the remote server. This date will be in a UNIX time
format (seconds since 1970)
- "postok()"
- "postok" will return true if the
servers initial response indicated that it will allow posting.
- "authinfo($user, $pass)"
- Authenticates to the server (using the original AUTHINFO USER / AUTHINFO
PASS form, defined in RFC2980) using the supplied username and password.
Please note that the password is sent in clear text to the server. This
command should not be used with valuable passwords unless the connection
to the server is somehow protected.
- "authinfo_simple($user, $pass)"
- Authenticates to the server (using the proposed NNTP V2 AUTHINFO SIMPLE
form, defined and deprecated in RFC2980) using the supplied username and
password. As with "authinfo" the password is sent in clear
text.
- "list()"
- Obtain information about all the active newsgroups. The results is a
reference to a hash where the key is a group name and each value is a
reference to an array. The elements in this array are:- the last article
number in the group, the first article number in the group and any
information flags about the group.
- "newgroups($since[, $distributions])"
- $since is a time value and
$distributions is either a distribution pattern or
a reference to a list of distribution patterns. The result is the same as
"list", but the groups return will be
limited to those created after $since and, if
specified, in one of the distribution areas in
$distributions.
- "newnews($since[, $groups[, $distributions]])"
- $since is a time value.
$groups is either a group pattern or a reference
to a list of group patterns. $distributions is
either a distribution pattern or a reference to a list of distribution
patterns.
Returns a reference to a list which contains the message-ids
of all news posted after $since, that are in a
groups which matched $groups and a distribution
which matches $distributions.
- "next()"
- Set the "current article pointer" to the next article in the
current newsgroup.
Returns the message-id of the article.
- "post([$message])"
- Post a new article to the news server. If $message
is specified and posting is allowed then the message will be sent.
If $message is not specified then the
message must be sent using the
"datasend" and
"dataend" methods from Net::Cmd
$message can be either an array of
lines or a reference to an array and must be encoded by the caller to
octets of whatever encoding is required, e.g. by using the Encode
module's "encode()" function.
The message, either sent via
"datasend" or as the
$message parameter, must be in the format as
described by RFC822 and must contain From:, Newsgroups: and Subject:
headers.
- "postfh()"
- Post a new article to the news server using a tied filehandle. If posting
is allowed, this method will return a tied filehandle that you can
print() the contents of the article to be posted. You must
explicitly close() the filehandle when you are finished posting the
article, and the return value from the close() call will indicate
whether the message was successfully posted.
- "slave()"
- Tell the remote server that I am not a user client, but probably another
news server.
- "quit()"
- Quit the remote server and close the socket connection.
- "can_inet6()"
- Returns whether we can use IPv6.
- "can_ssl()"
- Returns whether we can use SSL.
These methods use commands that are not part of the RFC977 documentation. Some
servers may not support all of them.
- "newsgroups([$pattern])"
- Returns a reference to a hash where the keys are all the group names which
match $pattern, or all of the groups if no pattern
is specified, and each value contains the description text for the
group.
- "distributions()"
- Returns a reference to a hash where the keys are all the possible
distribution names and the values are the distribution descriptions.
- "distribution_patterns()"
- Returns a reference to an array where each element, itself an array
reference, consists of the three fields of a line of the distrib.pats list
maintained by some NNTP servers, namely: a weight, a wildmat and a value
which the client may use to construct a Distribution header.
- "subscriptions()"
- Returns a reference to a list which contains a list of groups which are
recommended for a new user to subscribe to.
- "overview_fmt()"
- Returns a reference to an array which contain the names of the fields
returned by "xover".
- "active_times()"
- Returns a reference to a hash where the keys are the group names and each
value is a reference to an array containing the time the groups was
created and an identifier, possibly an Email address, of the creator.
- "active([$pattern])"
- Similar to "list" but only active groups
that match the pattern are returned. $pattern can
be a group pattern.
- "xgtitle($pattern)"
- Returns a reference to a hash where the keys are all the group names which
match $pattern and each value is the description
text for the group.
- "xhdr($header, $message_spec)"
- Obtain the header field $header for all the
messages specified.
The return value will be a reference to a hash where the keys
are the message numbers and each value contains the text of the
requested header for that message.
- "xover($message_spec)"
- The return value will be a reference to a hash where the keys are the
message numbers and each value contains a reference to an array which
contains the overview fields for that message.
The names of the fields can be obtained by calling
"overview_fmt".
- "xpath($message_id)"
- Returns the path name to the file on the server which contains the
specified message.
- "xpat($header, $pattern, $message_spec)"
- The result is the same as "xhdr" except
the is will be restricted to headers where the text of the header matches
$pattern
- "xrover($message_spec)"
- The XROVER command returns reference information for the article(s)
specified.
Returns a reference to a HASH where the keys are the message
numbers and the values are the References: lines from the articles
- "listgroup([$group])"
- Returns a reference to a list of all the active messages in
$group, or the current group if
$group is not specified.
- "reader()"
- Tell the server that you are a reader and not another server.
This is required by some servers. For example if you are
connecting to an INN server and you have transfer permission your
connection will be connected to the transfer daemon, not the NNTP
daemon. Issuing this command will cause the transfer daemon to hand over
control to the NNTP daemon.
Some servers do not understand this command, but issuing it
and ignoring the response is harmless.
The following NNTP command are unsupported by the package, and there are no
plans to do so.
AUTHINFO GENERIC
XTHREAD
XSEARCH
XINDEX
- $message_spec
- $message_spec is either a single message-id, a
single message number, or a reference to a list of two message numbers.
If $message_spec is a reference to a
list of two message numbers and the second number in a range is less
than or equal to the first then the range represents all messages in the
group after the first message number.
NOTE For compatibility reasons only with earlier
versions of Net::NNTP a message spec can be passed as a list of two
numbers, this is deprecated and a reference to the list should now be
passed
- $pattern
- The "NNTP" protocol uses the
"WILDMAT" format for patterns. The
WILDMAT format was first developed by Rich Salz based on the format used
in the UNIX "find" command to articulate file names. It was
developed to provide a uniform mechanism for matching patterns in the same
manner that the UNIX shell matches filenames.
Patterns are implicitly anchored at the beginning and end of
each string when testing for a match.
There are five pattern matching operations other than a strict
one-to-one match between the pattern and the source to be checked for a
match.
The first is an asterisk "*"
to match any sequence of zero or more characters.
The second is a question mark
"?" to match any single character. The
third specifies a specific set of characters.
The set is specified as a list of characters, or as a range of
characters where the beginning and end of the range are separated by a
minus (or dash) character, or as any combination of lists and ranges.
The dash can also be included in the set as a character it if is the
beginning or end of the set. This set is enclosed in square brackets.
The close square bracket "]" may be
used in a set if it is the first character in the set.
The fourth operation 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 caret character "^" at
the beginning of the test string just inside the open square
bracket.
The final operation uses the backslash character to invalidate
the special meaning of an open square bracket
"[", the asterisk, backslash or the
question mark. Two backslashes in sequence will result in the evaluation
of the backslash as a character with no special meaning.
- Examples
- "[^]-]"
- matches any single character other than a close square bracket or a minus
sign/dash.
- *bdc
- matches any string that ends with the string "bdc" including the
string "bdc" (without quotes).
- "[0-9a-zA-Z]"
- matches any single printable alphanumeric ASCII character.
- "a??d"
- matches any four character string which begins with a and ends with
d.
See
<https://rt.cpan.org/Dist/Display.html?Status=Active&Queue=libnet>.
Net::Cmd, IO::Socket::SSL.
Graham Barr <gbarr@pobox.com <mailto:gbarr@pobox.com>>.
Steve Hay <shay@cpan.org <mailto:shay@cpan.org>> is
now maintaining libnet as of version 1.22_02.
Copyright (C) 1995-1997 Graham Barr. All rights reserved.
Copyright (C) 2013-2016, 2020 Steve Hay. All rights reserved.
This module is free software; you can redistribute it and/or modify it under the
same terms as Perl itself, i.e. under the terms of either the GNU General
Public License or the Artistic License, as specified in the LICENCE
file.
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