sys,newsfeeds(5)

NAME
sys,newsfeeds - list of connected systems

DESCRIPTION

The sys or newsfeeds file is one of the most important files in the NEWS system. It defines the names (and/or classes) of the news groups in which the local system is interested, and it defines to which distribution codes the system belongs. Also, it defines the systems that are connected to the local system, exchanging NEWS articles. Only one of these files (sys or newsfeeds) is allowed, since the functionality is the same, only the syntax is different. The W-NEWS system decides which format to use by probing for these files; if both are found, a warning is issued and the sys file is prefered. These files can be found in /usr/lib/news or /conf/news, depending on your system.

As most files in the NEWS system, sys/newsfeeds is a simple ASCII text file, with one line describing exactly one system. This line may span multiple lines in the file, if every newline is escaped by a backslash, similair to the large entries in the /etc/termcap database. The line format for these files is defined as follows:

sysname:distribution and subscriptions:transport:filename

In this format, there are four fields, separated from each other by colons. The first field contains the UUCP name of the system to be defined. It MAY be the text ME to indicate (in a portable manner) that this entry is for the local system. In this field an alternate name may also be defined, this is useful if the system does not put it's uucp name into the Path: line (see the example below). The third field describes how this system wants to receive the articles, since not all systems can do it using the same protocol. The field contains a single-character transport code, which can be one of the following:

B - use B News article format

F - use batches of 'B' formatted articles

X - use a special program to deliver

The default (i.e. no code at all- an empty field) is the same as B , since that is the most often used format of articles. Note, that W-NEWS does NOT support the old A News formatted articles. If the 'B' format is selected, then the fourth field is neither used nor checked. The article is sent to the system via the UUCP system uux(1C) command at once. The UUCP system then decides if the call should be made at once or not.

If the F code is selected, the article will be added to the list of articles that have to be sent to that system. The name of this list file is expected to be in the fourth field, and defaults to:

/usr/spool/batch/sysname or /var/spool/news/.outgoing/sysname , depending on your setup.

if no name is presented there. See the chapters on the sendbatch(8) and unbatch(8) programs for more details on how a batch of articles is created.

Finally, the X code can be used to specify the path name of the special program to be used for the delivery. This is mostly useful for sending articles to an automated archiving system, like in the example file below. The complete path name plus the arguments to the program are expected to be in the fourth field.

A sample sys file might look like this:

 ME::F:
 mugnet/nic.nl.mugnet.org:world,nl,mugnet,all.all:F:
 archive:world,nl,mugnet.sources:X:/usr/ucb/archive -I

A sample newsfeeds file might look like this:

 mugnet/nic.nl.mugnet.org:*/world,nl,mugnet:F:
 archive:mugnet.sources/world,nl:X:/usr/ucb/archive -I

Now, what is this silly stuff in the second field about? It looks rather odd, eh?

Well, the second field is called the subscribtion list of that system. It also contains the code of the distributions to which that systems belongs. All subfields in this field are separated by commas, as can be seen above.

  sys format
Usually, the field starts with the list of distribution code. Then, all news group classes (i.e. names without dots- see below), possibly followed by a number of selected news groups.

The NEWS system uses a wildcarding scheme that is somewhat similar to the use of the asterisk (*) in the standard UNIX shell. Instead of the asterisk, the term all (or simply no term at all) is used as a wildcard. So, the text:

world,comp,soc.culture.all,sci.all

means: all groups below the comp class (in shell notation: comp.*), plus all groups below the soc.culture and sci level. This scheme allows one to subscribe to a large number of news groups without the need for enourmous subscription lists.

However, one has to be able to tell the system that only certain news groups are not of interest to the system. For example, if we expand the above example to:

world,comp,soc.culture.all,!comp.os.msdos

then all groups in the comp class will be received except for the comp.os.msdos news group. So, one can start off with specifying ALL, followed by a certain number of not subscriptions...

  newsfeeds format
This format is almost the same, the difference is that the '*' character is used for wildcarding, and there is no default wildcard- to specify all groups below 'comp', one should use 'comp.*'. Also the distribution list has a separate field - it is separated from the subscription list by a / (slash); but if it's not present the default is 'all'. Note that there is no wildcarding allowed in the distribution list. The same rules for negation (with a ! (exclamation point)) apply as for the sys file format explained above. The newsfeeds file does not need a specific entry for ME, the host system itself. (In fact, the sys file doesn't need it either. Don't tell mom.)

The special entry ME had meaning in the old days, when it was not possible to fine adjust the newsfeed you got. Then the ME entry had the local system's subscription list, so that unwanted news dissappeared into the junk news group, to be expired as quick as possible. Wnews can also use the ME entry for another purpose: to state which system name should appear in the Path: header line for articles originating from or passing through the local system. Say your system name is kremvax.kgb.su, but you want only your uucp name to appear in the Path: header line. The next entry in the sys or newsfeeds file will make this happen:

ME/kgbvax::F:

Note, that the larger NEWS software packages have lots of other options that can be presented in this file. However, for the sake of simplicitly, most of them have not been implemented in W-NEWS, and probably never will to keep the package as small and fast as possible!

FILES
/usr/lib/news/sys or /conf/news/sys
/usr/lib/news/newsfeeds or /uconf/news/newsfeeds

AUTHOR
Miquel van Smoorenburg, miquels@drinkel.ow.org
Fred N. van Kempen, waltje@Infomagic.COM