NEWSFEEDS(5) File Formats Manual NEWSFEEDS(5)
NAME
newsfeeds - determine where Usenet articles get sent
DESCRIPTION
The file <pathetc in inn.conf>/newsfeeds specifies how incoming articles should be distributed to other sites. It is parsed by the Inter-
NetNews server innd(8) when it starts up, or when directed to by ctlinnd(8).
The file is interpreted as a set of lines according to the following rules. If a line ends with a backslash, then the backslash, the new-
line, and any whitespace at the start of the next line is deleted. This is repeated until the entire ``logical'' line is collected. If
the logical line is blank, or starts with a number sign (``#''), it is ignored.
All other lines are interpreted as feed entries. An entry should consist of four colon-separated fields; two of the fields may have
optional sub-fields, marked off by a slash. Fields or sub-fields that take multiple parameters should be separated by a comma. Extra
whitespace can cause problems. Except for the site names, case is significant. The format of an entry is:
sitename[/exclude,exclude,...]
:pattern,pattern...[/distrib,distrib...]
:flag,flag...
:param
Each field is described below.
The sitename is the name of the site to which a news article can be sent. It is used for writing log entries and for determining if an
article should be forwarded to a site. If sitename already appears in the article's Path header, then the article will not be sent to the
site. The name is usually whatever the remote site uses to identify itself in the Path line, but can be almost any word that makes sense;
special local entries (such as archivers or gateways) should probably end with an exclamation point to make sure that they do not have the
same name as any real site. For example, ``gateway'' is an obvious name for the local entry that forwards articles out to a mailing list.
If a site with the name ``gateway'' posts an article, when the local site receives the article it will see the name in the Path and not
send the article to its own ``gateway'' entry. See also the description of the ``Ap'' flag, below. If an entry has an exclusion sub-
field, then the article will not be sent to that site if any of the names specified as excludes appear in the Path header. The same site-
name can be used more than once -- the appropriate action will be taken for each entry that should receive the article, regardless of the
name -- although this is recommended only for program feeds to avoid confusion. Case is not significant in site names.
The patterns specify which groups to send to the site and are interpreted to build a ``subscription list'' for the site. The default sub-
scription is to get all groups. The patterns in the field are wildmat(3)-style patterns, and are matched in order against the list of
newsgroups that the local site receives. If the first character of a pattern is an exclamation mark, then any groups matching the pattern
are removed from the subscription, otherwise any matching groups are added. For example, to receive all ``comp'' groups, but only
comp.sources.unix within the sources newsgroups, the following set of patterns can be used:
comp.*,!comp.sources.*,comp.sources.unix
There are three things to note about this example. The first is that the trailing ``.*'' is required. The second is that, again, the
result of the last match is the most important. The third is that ``comp.sources.*'' could be written as ``comp.sources*'' but this would
not have the same effect if there were a ``comp.sources-only'' group.
There is also a way to subscribe to a newsgroup negatively. That is to say, do not send this group even if the article is cross-posted to
a subscribed newsgroup. If the first character of a pattern is an atsign ``@'', it means that any article posted to a group matching the
pattern will not be sent even though the article may be cross-posted to a group which is subscribed. The same rules of precedence apply in
that the last match is the one which counts. For example, if you want to prevent all articles posted to any "alt.binaries.warez" group
from being propagated even if it is cross-posted to another "alt" group or any other group for that matter, then the following set of pat-
terns can be used:
alt.*,@alt.binaries.warez.*,misc.*
If you reverse the alt.* and alt.binaries.warez.* patterns, it would nullify the atsign because the result of the last match is the one
that counts. Using the above example, if an article is posted to one or more of the alt.binaries.warez.* groups and is cross-posted to
misc.test, then the article is not sent.
See innd(8) for details on the propagation of control messages.
A subscription can be further modified by specifying ``distributions'' that the site should or should not receive. The default is to send
all articles to all sites that subscribe to any of the groups where it has been posted , but if an article has a Distribution header and
any distribs are specified, then they are checked according to the following rules:
1. If the Distribution header matches any of the values in the sub-field, then the article is sent.
2. If a distrib starts with an exclamation point, and it matches the Distribution header, then the article is not sent.
3. If Distribution header does not match any distrib in the site's entry, and no negations were used, then the article is not sent.
4. If Distribution header does not match any distrib in the site's entry, and any distrib started with an exclamation point, then the
article is sent.
If an article has more than one distribution specified, then each one is according to the above rules. If any of the specified distribu-
tions indicate that the article should be sent, it is; if none do, it is not sent -- the rules are used as a ``logical or.'' It is almost
definitely a mistake to have a single feed that specifies distributions that start with an exclamation point along with some that don't.
Distributions are text words, not patterns; entries like ``*'' or ``all'' have no special meaning.
The flags parameter specifies miscellaneous parameters. They may be specified in any order; flags that take values should have the value
immediately after the flag letter with no whitespace. The valid flags are:
<size An article will only be sent to the site if it is less than size bytes long. The default is no limit.
>size An article will only be sent to the site if it is greater than size bytes long. The default is no limit.
Achecks
An article will only be sent to the site if it meets the requirements specified in the checks, which should be chosen from the fol-
lowing set:
c Exclude all kinds of control messages
C Only include all kinds of control messages
d Distribution header required
e Only include message whose newsgroups in
Newsgroups header all exist in active
o Overview data is created
O Propagate articles without X-Trace header
even if ``O'' flag is specified
p Do not check Path header for the sitename
before propagating (the exclusions are
still checked).
If both ``c'' and ``C'' are specified simultaneously, the last specified one is adopted.
Bhigh/low
If a site is being fed by a file, channel, or exploder (see below), the server will normally start trying to write the information
as soon as possible. Providing a buffer may give better system performance and help smooth out overall load if a large batch of
news comes in. The value of the this flag should be two numbers separated by a slash. The first specifies the point at which the
server can start draining the feed's I/O buffer, and the second specifies when to stop writing and begin buffering again; the units
are bytes. The default is to do no buffering, sending output as soon as it is possible to do so.
Ccount If this flag is specified, an article will only be sent to the site if the following is true: The number of groups it is posted to,
plus the square of the number of groups followups would appear in, is no more than count newsgroups. 30 is a good value for this
flag.
Fname This flag specifies the name of the file that should be used if it is necessary to begin spooling for the site (see below). If name
is not an absolute pathname, it is taken to be relative to <pathoutgoing in inn.conf>. Then, if the destination is a directory, the
file togo in that directory will be used as filename.
Gcount If this flag is specified, an article will only be sent to the site if it is posted to no more than count newsgroups. This has the
problem of filtering out many FAQs, and also RFDs/CFVs for group creation. The C or U flags are a better solution.
Hcount If this flag is specified, an article will only be sent to the site if it has count or fewer sites in its Path line. This flag
should only be used as a rough guide because of the loose interpretation of the Path header; some sites put the poster's name in the
header, and some sites that might logically be considered to be one hop become two because they put the posting workstation's name
in the header. The default value for count is one.
Isize The flag specifies the size of the internal buffer for a file feed. If there are more file feeds than allowed by the system, they
will be buffered internally in least-recently-used order. If the internal buffer grows bigger then size bytes, however, the data
will be written out to the appropriate file. The default value is <SITE_BUFFER_SIZE in include/config.h> (typically (16 * 1024 ))
bytes.
Nmodifiers
The newsgroups that a site receives are modified according to the modifiers, which should be chosen from the following set:
m Only moderated groups
u Only unmoderated groups
OOriginator
If this flag is used then articles sent to this feed must contain a X-Trace header and the first field in the header must match
originator. Originator can be a list of wildmat(3)-style pattern. The list is separated by ``/''. Article is never sent, if the
first character of the pattern begins with ``@'' and rest of the pattern matches. One use of this flag is to restrict the feed to
locally generated posts.
Ppriority
The nice priority that this channel or program feed should receive. This should be a positive number between 0 and 20, and is the
priority that the new process will run with. This flag can be used to raise the priority to normal if you are using the
``nicekids'' in inn.conf(5).
Ssize If the amount of data queued for the site gets to be larger than size bytes, then the server will switch to spooling, appending to a
file specified by the ``F'' flag, or <pathoutgoing in inn.conf>/sitename if the ``F'' flag is not specified. Spooling usually hap-
pens only for channel or exploder feeds.
Ttype This flag specifies the type of feed for the site. Type should be a letter chosen from the following set:
c Channel
f File
l Log entry only
m Funnel (multiple entries feed into one)
p Program
x Exploder
Each feed is described below in the section on feed types. The default is Tf.
Ucount If this flag is specified, an article will only be sent to the site if followups to this article would be posted to no more than
count newsgroups.
Witems If a site is fed by file, channel, or exploder, this flag controls what information is written. If a site is fed by a program, only
the asterisk (``*'') has any effect. The items should be chosen from the following set:
b Size of wire formatted article in bytes
e The time article will be expired as
seconds since epoch
``0'' means there is no ``Expires'' header
f Token of the article (equivalent to ``n''),
use sm(8) to get the actual article
g The newsgroup the article is in;
if cross-posted, then the first of the
groups this site gets (the differnece from
``G'' is that article belongs to its
newsgroup even if it is congrol message)
h Article's Message-ID hash key
m Article's Message-ID
n Token of the article, use sm(8) to get the
actual article
p The time the article was posted as seconds
since epoch
s The site that fed the article to the
server; from the Path: header or the IP
address of the site that sent the article
depending on the ``logipaddr'' field in
inn.conf(8);
if ``logipaddr'' is ``true'' and IP
address is ``0.0.0.0'' which means the
article is feeded from localhost (e.g.
from rnews), the result will be retrieved
from Path: header
t The time article was received as seconds
since epoch
* Names of the appropriate funnel entries;
or all sites that get the article
D Value of the Distribution header; ? if
none present
G Where the article is stored; if cross-
posted, then the first of the groups this
site gets (the differnece from ``g'' is
that cmsg belongs to ``control.cmsg'')
H All headers
N Value of the Newsgroups header
P Article's Path header
O Overview data
R Information needed for replication
More than one letter can be used; the entries will be separated by a space, and written in the order in which they are specified.
The default is Wn.
The ``H'' and ``O'' items are intended for use by programs that create news overview databases. If ``H'' is present, then the all
the article's headers are written followed by a blank line. An Xref header (even if one does not appear in the filed article) and a
Bytes header, specifying the article's size (see ``b'' description below for clarifying size meaning), will also be part of the
headers. If used, this should be the only item in the list; if preceded by other items, however, a newline will be written before
the headers. The ``nteO'' generates input to the overchan(8) program.
The asterisk has special meaning. It expands to a space-separated list of all sites that received the current article. If the site
is the target of a funnel however (i.e., it is named by other sites which have a ``Tm'' flag), then the asterisk expands to the
names of the funnel feeds that received the article. If the site is fed by a program, then an asterisk in the param field will be
expanded into the list of funnel feeds that received the article. A site fed by a program cannot get the site list unless it is the
target of other ``Tm'' feeds.
The interpretation of the param field depends on the type of feed, and is explained in more detail below in the section on feed types. It
can be omitted.
The site named ME is special. There must be exactly one such entry, and it should be the first entry in the file. If the ME entry has an
exclusion sub-field, then the articles are rejected if any of the names specified as excludes appear in the Path header. If the ME entry
has a subscription list, then that list is automatically prepended to the subscription list of all other entries. For example, ``*,!con-
trol,!junk,!foo.*'' can be used to set up the initial subscription list for all feeds so that local postings are not propagated unless
``foo.*'' explicitly appears in the site's subscription list. Note that most subscriptions should have ``!junk,!control'' in their pattern
list; see the discussion of ``control messages'' in innd(8). (Unlike other news software, it does not affect what groups are received;
that is done by the active(5) file.)
If the ME entry has a distribution subfield, then only articles that match the distribution list are accepted; all other articles are
rejected. A commercial news server, for example, might have ``/!local'' to reject local postings from other, misconfigured, sites.
FEED TYPES
Innd provides four basic types of feeds: log, file, program, and channel. An exploder is a special type of channel. In addition, several
entries can feed into the same feed; these are funnel feeds, that refer to an entry that is one of the other types. Note that the term
``feed'' is technically a misnomer, since the server does not transfer articles, but reports that an article should be sent to the site.
The simplest feed is one that is fed by a log entry. Other than a mention in the news logfile, <pathlog in inn.conf>/news, no data is ever
written out. This is equivalent to a ``Tf'' entry writing to /dev/null except that no file is opened.
A site fed by a file is the next simplest type of feed. When the site should receive an article, one line is written to the file named by
the param field. If param is not an absolute pathname, it is taken to be relative to <pathoutgoing in inn.conf>. If empty, the filename
defaults to <pathoutgoing in inn.conf>/sitename. This name should be unique.
When a site fed by a file is flushed (see ctlinnd), the following steps are performed. The script doing the flush should have first
renamed the file. The server tries to write out any buffered data, and then closes the file. The renamed file is now available for use.
The server will then re-open the original file, which will now get created.
A site fed by a program has a process spawned for every article that the site receives. The param field must be a sprintf(3) format string
that may have a single %s parameter, which will be a token. Standard input will not be set to the article. Standard output and error will
be set to the error log ( <pathlogininn.conf>/errlog.) The process will run with the user and group ID of the <pathrun in inn.conf> direc-
tory. Innd will try to avoid spawning a shell if the command has no shell meta-characters; this feature can be defeated by appending a
semi-colon to the end of the command. The full pathname of the program to be run must be specified; for security, PATH environment is not
searched.
If the entry is the target of a funnel, and if the ``W*'' flag is used, then a single asterisk may be used in the param field where it will
be replaced by the names of the sites that fed into the funnel. If the entry is not a funnel, or if the ``W*'' flag is not used, then the
asterisk has no special meaning.
Flushing a site fed by a program does no action.
When a site is fed by a channel or exploder, the param field names the process to start. Again, the full pathname of the process must be
given. When the site is to receive an article, the process receives a line on its standard input telling it about the article. Standard
output and error, and the user and group ID of the all sub-process are set as for a program feed, above. If the process exits, it will be
restarted. If the process cannot be started, the server will spool input to a file named <pathoutgoing in inn.conf>/sitename. It will
then try to start the process some time later.
When a site fed by a channel or exploder is flushed, the server closes down its end of the pipe. Any pending data that has not been writ-
ten will be spooled; see the description of the ``S'' flag, above. No signal is sent; it is up to the program to notice EOF on its stan-
dard input and exit. The server then starts a new process.
Exploders are a superset of channel feeds. In addition to channel behavior, exploders can be sent command lines. These lines start with
an exclamation point, and their interpretation is up to the exploder. The following messages are generated automatically by the server:
newgroup group
rmgroup group
flush
flush site
These messages are sent when the ctlinnd command of the same name is received by the server. In addition, the ``send'' command can be used
to send an arbitrary command line to the exploder child-process. The primary exploder is buffchan(8).
Funnel feeds provide a way of merging several site entries into a single output stream. For a site feeding into a funnel, the param field
names the actual entry that does the feeding.
EXAMPLES
## Initial subscription list and our distributions.
ME:*,!junk,!foo.*/world,usa,na,ne,foo,ddn,gnu,inet
::
## Feed all moderated source postings to an archiver
source-archive!:!*,*sources*,!*wanted*,!*.d
:Tc,Wn:<PREFIX specified with --prefix at configure>/bin/archive -f -i
/usr/spool/news.archive/INDEX
## Watch for big postings
watcher!:*
:Tc,Wbnm
:exec awk '$1 > 1000000 { print "BIG", $2, $3 }' >/dev/console
## A UUCP feed, where we try to keep the "batching" between 4 and 1K.
ihnp4:/world,usa,na,ddn,gnu
:Tf,Wnb,B4096/1024:
## Usenet as mail; note ! in funnel name to avoid Path conflicts.
## Can't use ! in "fred" since it would like look a UUCP address.
fred:!*,comp.sources.unix,comp.sources.bugs
:Tm:mailer!
barney@bar.com:!*,news.software.nntp,comp.sources.bugs
:Tm:mailer!
mailer!:!*
:W*,Tp:/usr/ucb/Mail -s "News article" *
## NNTP feeds fed off-line via nntpsend or equivalent.
feed1::Tf,Wnm:feed1.domain.name
peer.foo.com:foo.*:Tf,Wnm:peer.foo.com
## Real-time transmission.
mit.edu:/world,usa,na,ne,ddn,gnu,inet
:Tc,Wnm:<PREFIX specified with --prefix at configure>/bin/nntplink -i stdin mit.edu
## Two sites feeding into a hypothetical NNTP fan-out program:
nic.near.net:
:Tm:nntpfunnel1
uunet.uu.net/uunet:!ne.*/world,usa,na,foo,ddn,gnu,inet
:Tm:nntpfunnel1
nntpfunnel1:!*
:Tc,Wmn*:<PREFIX specified with --prefix at configure>/bin/nntpfanout
## A UUCP site that wants comp.* and moderated soc groups
uucpsite!comp:!*,comp.*/world,usa,na,gnu
:Tm:uucpsite
uucpsite!soc:!*,soc.*/world,usa,na,gnu
:Tm,Nm:uucpsite
uucpsite:!*
:Tf,Wnb:/usr/spool/batch/uucpsite
The last two sets of entries show how funnel feeds can be used. For example, the nntpfanout program would receive lines like the following
on its standard input:
<123@litchi.foo.com> comp/sources/unix/888 nic.near.net uunet.uu.net
<124@litchi.foo.com> ne/general/1003 nic.near.net
Since the UUCP funnel is only destined for one site, the asterisk is not needed and entries like the following will be written into the
file:
<qwe#37x@snark.uu.net> comp/society/folklore/3
<123@litchi.foo.com> comp/sources/unix/888
HISTORY
Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews. This is revision 1.29.2.2, dated 2002/08/23.
SEE ALSO
active(5), buffchan(8), ctlinnd(8), inn.conf(5), innd(8), wildmat(3).
NEWSFEEDS(5)