NAME

       Net::NNTP - NNTP Client class

SYNOPSIS

           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;

DESCRIPTION

       "Net::NNTP" is a class implementing a simple NNTP client in Perl as described in RFC977 and RFC4642.

       The Net::NNTP class is a subclass of Net::Cmd and IO::Socket::INET.

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.

           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 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.

           LocalAddr - If multiple IP addresses are present on the client host with a valid route to the
           destination, you can specify the address your "Net::NNTP" connects from and this way override the
           operating system's pick.

METHODS

       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 the 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.

       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.

           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.

   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 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 ()
           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.

UNSUPPORTED

       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 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 ALSO

       Net::Cmd, IO::Socket::SSL

AUTHOR

       Graham Barr <gbarr@pobox.com>

       Steve Hay <shay@cpan.org> is now maintaining libnet as of version 1.22_02

COPYRIGHT

       Versions up to 2.24_1 Copyright (c) 1995-1997 Graham Barr. All rights reserved.  Changes in Version 2.25
       onwards Copyright (C) 2013-2014 Steve Hay.  All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl
       itself.