21.3. The sys File

This is the name of the site the entry applies to. One usually chooses the site's UUCP name for this. There has to be an entry for your site in the sys file too, or you will not receive any articles yourself.

The special site name ME denotes your site. The ME entry defines all groups you are willing to store locally. Articles that aren't matched by the ME line will go to the junk group.

C News rejects any articles that have already passed through this site to prevent loops. C News does this by ensuring that the local site name does not appear in the Path: of the article. Some sites may be known by a number of valid names. For example, some sites use their fully qualified domain name in this field, or an alias like news.site.domain. To ensure the loop prevention mechanism works, it is important to add all aliases to the exclusion list, separating them by commas.

For the entry applying to site moria, for instance, the site field would contain moria/moria.orcnet.org. If moria were also by an alias of news.orcnet.org, then our site field would contain moria/moria.orcnet.org,news.orcnet.org.

This is a comma-separated subscription list of groups and hierarchies for this particular site. A hierarchy may be specified by giving the hierarchy's prefix (such as comp.os for all groups whose names start with this prefix), optionally followed by the keyword all (e.g., comp.os.all ).

You can exclude a hierarchy or group from forwarding by preceding it with an exclamation mark. If a newsgroup is checked against the list, the longest match applies. For example, if grouplist contains this list:

!comp,comp.os.linux,comp.folklore.computers

If the site requests to be forwarded all news you receive yourself, enter all as grouplist.

This value is offset from the grouplist by a slash and contains a list of distributions to be forwarded. Again, you may exclude certain distributions by preceding them with an exclamation mark. All distributions are denoted by all. Omitting distlist implies a list of all.

For example, you may use a distribution list of all,!local to prevent news meant only for local use from being sent to remote sites.

There are usually at least two distributions: world, which is often the default distribution used when none is specified by the user, and local. There may be other distributions that apply to a certain region, state, country, etc. Finally, there are two distributions used by C News only; these are sendme and ihave, and are used for the sendme/ihave protocol.

The use of distributions is a subject of debate. The distribution field in a news article can be created arbitrarily, but for a distribution to be effective, the news servers in the network must know it. Some misbehaving newsreaders create bogus distributions by simply assuming the top-level newsgroup hierarchy of the article destination is a reasonable distribution. For example, one might assume comp to be a reasonable distribution to use when posting to the comp.os.linux.networking newsgroup. Distributions that apply to regions are often questionable, too, because news may travel outside of your region when sent across the Internet.[1] Distributions applying to an organization, however, are very meaningful; e.g., to prevent confidential information from leaving the company network. This purpose, however, is generally served better by creating a separate newsgroup or hierarchy.

This option describes certain parameters for the feed. It may be empty or a combination of the following:

You may use at most one of F, f, I, or n.

This field contains a command that will be executed for each article, unless you enable batching. The article will be fed to the command on standard input. This should be used for very small feed only; otherwise, the load on both systems will be too high.

The default command is:

uux - -r -z remote-system!rnews

This invokes rnews on the remote system, feeding it the article on standard input.

The default search path for commands given in this field is /bin:/usr/bin:/usr/lib/news/batch. The latter directory contains a number of shell scripts whose names start with via ; they are briefly described later in this chapter.

If batching is enabled using one of the F, f, I, or n flags, C News expects to find a filename in this field rather than a command. If the filename does not begin with a slash (/ ), it is assumed to be relative to /var/spool/news/out.going. If the field is empty, it defaults to remote-system/togo. The file is expected to be in the same format as the remote-system/togo file and contain a list of articles to transmit.