Olaf Kirch - Linux Network Administrator Guide, Second Edition

This is a companion file of active that contains a list of each newsgroup name along with a one-line description of its main topic. This file is automatically updated when C News receives a checknews control message.

localgroups

If you have a lot of local groups, you can keep C News from complaining about them each time you receive a checkgroups message by putting their names and descriptions in this file, just as they would appear in newsgroups .

mailpaths

This file contains the moderator's address for each moderated group. Each line contains the group name followed by the moderator's email address (offset by a tab).

Two special entries are provided as defaults: backbone and internet . Both provide, in bang-path notation, the path to the nearest backbone site and the site that understands RFC-822 style addresses (user@host). The default entries are:

internet backbone

You do not have to change the internet entry if you have exim or sendmail installed; they understand RFC-822 addressing.

The backbone entry is used whenever a user posts to a moderated group whose moderator is not listed explicitly. If the newsgroup's name is alt.sewer and the backbone entry contains path!%s, C News will mail the article to path!alt-sewer, hoping that the backbone machine is able to forward the article. To find out which path to use, ask the news-admin at the site that feeds you. As a last resort, you can also use uunet.uu.net!%s.

distributions

This file is not really a C News file, but is used by some newsreaders and nntpd. It contains the list of distributions recognized by your site and a description of their (intended) effects. For example, Virtual Brewery has the following file:

world everywhere in the world

local Only local to this site

nl Netherlands only

mugnet MUGNET only

fr France only

de Germany only

brewery Virtual Brewery only

log

This file contains a log of all C News activities. It is culled regularly by running newsdaily; copies of the old log files are kept in log.o , log.oo , etc.

errlog

This is a log of all error messages created by C News. These messages do not include logs of articles junked due to being sent to an invalid wrong group or other user errors. This file is mailed to the newsmaster ( usenet by default) automatically by newsdaily if it is not found empty.

errlog is cleared by newsdaily. errlog.o keeps old copies and companions.

batchlog

This file logs all runs of sendbatches. It is usually of scant interest. It is also attended by newsdaily.

watchtime

This is an empty file created each time newswatch runs.

The Usenet news protocol knows a special category of articles that evoke certain responses or actions by the news system. These are called control messages. They are recognized by the presence of a Control: field in the article header, which contains the name of the control operation to be performed. There are several types of them, all of which are handled by shell scripts located in /usr/lib/news/ctl .

Most of these messages perform their action automatically at the time the article is processed by C News without notifying the newsmaster. By default, only checkgroups messages will be handed to the newsmaster, but you may change this by editing the scripts.

The most widely known message is cancel , with which a user can cancel an article sent earlier. This effectively removes the article from the spool directories, if it exists. The cancel message is forwarded to all sites that receive news from the groups affected, regardless of whether the article has been seen already. This takes into account the possibility that the original article has been delayed over the cancellation message. Some news systems allow users to cancel other people's messages; this is, of course, a definite no-no.

Two messages dealing with creation or removal of newsgroups are the newgroup and rmgroup messages. Newsgroups below the "usual" hierarchies may be created only after a discussion and voting has been held among Usenet readers. The rules applying to the alt hierarchy allow for something close to anarchy. For more information, see the regular postings in news.announce.newusers and news.announce.newgroups. Never send a newgroup or rmgroup message yourself unless you definitely know that you are allowed to.

checkgroups messages are sent by news administrators to make all sites within a network synchronize their active files with the realities of Usenet. For example, commercial Internet Service Providers might send out such a message to their customers' sites. Once a month, the "official" checkgroups message for the major hierarchies is posted to comp.announce.newgroups by its moderator. However, it is posted as an ordinary article, not as a control message. To perform the checkgroups operation, save this article to a file, say /tmp/check , remove everything up to the beginning of the control message itself, and feed it to the checkgroups script using the following command:

# su news -c "/usr/lib/news/ctl/checkgroups" ‹ /tmp/check

This will update your newsgroups file from the new list of groups, adding the groups listed in localgroups . The old newsgroups file will be moved to newsgroups.bac . Note that posting the message locally rarely works, because inews, the command that accepts and posts articles from users, refuses to accept that large an article.

If C News finds mismatches between the checkgroups list and the active file, it produces a list of commands that would bring your site up to date and mails it to the news administrator.

The output typically looks like this:

From news Sun Jan 30 16:18:11 1994

Date: Sun, 30 Jan 94 16:18 MET

From: news (News Subsystem)

To: usenet

Subject: Problems with your active file

The following newsgroups are not valid and should be removed.

alt.ascii-art

bionet.molbio.gene-org

comp.windows.x.intrisics

de.answers

You can do this by executing the commands:

/usr/lib/news/maint/delgroup alt.ascii-art

/usr/lib/news/maint/delgroup bionet.molbio.gene-org

/usr/lib/news/maint/delgroup comp.windows.x.intrisics

/usr/lib/news/maint/delgroup de.answers

The following newsgroups were missing.

comp.binaries.cbm

comp.databases.rdb

comp.os.geos

comp.os.qnx

comp.unix.user-friendly

misc.legal.moderated

news.newsites

soc.culture.scientists

talk.politics.crypto

talk.politics.tibet

When you receive a message like this from your news system, don't believe it automatically. Depending on who sent the checkgroups message, it may lack a few groups or even entire hierarchies; you should be careful about removing any groups. If you find groups are listed as missing that you want to carry at your site, you have to add them using the addgroup script. Save the list of missing groups to a file and feed it to the following little script: