Книга: Linux Network Administrator Guide, Second Edition

The checkgroups Message

The checkgroups Message

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:

#!/bin/sh
#
WHOIAM=`whoami`
if [ "$WHOIAM" != "news" ]
then
        echo "You must run $0 as user 'news'" >&2
        exit 1
fi
#
cd /usr/lib/news
while read group; do
    if grep -si "^$group[[:space:]].*moderated" newsgroup; then
        mod=m
    else
        mod=y
    fi
    /usr/lib/news/maint/addgroup $group $mod
done

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