Net::NNTP(3p) Perl Programmers Reference Guide Net::NNTP(3p)NAMENet::NNTP - NNTP Client class
SYNOPSIS
use Net::NNTP;
$nntp = Net::NNTP->new("some.host.name");
$nntp->quit;
DESCRIPTION
"Net::NNTP" is a class implementing a simple NNTP client in
Perl as described in RFC977. "Net::NNTP" inherits its com-
munication methods from "Net::Cmd"
CONSTRUCTOR
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.
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 nnrpd, by default "Net::NNTP" will
issue a "MODE READER" command so that the remote server
becomes innd. 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 nnrpd.
METHODS
Unless otherwise stated all methods return either a true or
false value, with true meaning that the operation was a suc-
cess. When a method states that it returns a value, failure
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will be returned as undef or an empty list.
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 suc-
cess a true value will be returned. If "FH" is not
specified then the return value, on success, will be a
reference to an array containg 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" com-
mand 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".
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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 contain-
ing, the number of articles in the group, the number of
the first article, the number of the last article and
the group name.
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 the it will be sent.
Returns true if the server desires the article and "MES-
SAGE" 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.
last ()
Set the "current article pointer" to the previous arti-
cle 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 AUTHINFO USER /
AUTHINFO PASS) 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 valu-
able passwords unless the connection to the server is
somehow protected.
list ()
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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 distri-
bution 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 pat-
tern or a reference to a list of group patterns. "DIS-
TRIBUTIONS" is either a distribution pattern or a refer-
ence 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.
The message, either sent via "datasend" or as the "MES-
SAGE" 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
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return a tied filehandle that you can print() the con-
tents 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.
Extension methods
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 dis-
tribution descriptions.
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 iden-
tifier, 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.
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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
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 per-
mission your connection will be connected to the
transfer daemon, not the NNTP daemon. Issuing this com-
mand 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.
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The following NNTP command are unsupported by the package,
and there are no plans to do so.
AUTHINFO GENERIC
XTHREAD
XSEARCH
XINDEX
DEFINITIONS
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 mes-
sage 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 ver-
sions 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 pat-
terns. 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 charac-
ters.
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
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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 ALSO
Net::Cmd
AUTHOR
Graham Barr <gbarr@pobox.com>
COPYRIGHT
Copyright (c) 1995-1997 Graham Barr. All rights reserved.
This program is free software; you can redistribute it
and/or modify it under the same terms as Perl itself.
$Id: //depot/libnet/Net/NNTP.pm#18 $
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