Il CD di internet/CD.iso/SOURCE/N/CNEWS/_CNEWS.TAR/usr/doc/cnews/README.old

Text File | 1994-09-02 | 9.8 KB | 189 lines

This is C News.

C News is a reimplementation of the transport and storage subsystems of the
news software -- basically, everything except news readers.  We supply a
simple news reader (written by Michael Rourke, included by permission,
slightly modified [so bugs are probably our fault]) as a replacement for
B-News readnews suited to use by occasional users.  For regular news users,
there are several more sophisticated readers widely available, and all should
work with C News.  We use Larry Wall's "rn" ourselves; we have not included
it because this distribution is already rather big.

C News's major advantage over B News is that it is much faster.  Timings
quite a while ago gave C News a speed advantage of roughly a factor of 25
in processing incoming batches.  This has probably improved a bit since.
C News is now, on good machines with good C libraries, mostly system-call
bound.  Use of system calls has been optimized with some care, so it's
unlikely that further big speed improvements can be made at user level
without sacrificing backward compatibility.  See our paper in the Winter '87
Usenix proceedings for some discussion of how the speed was achieved.

C News also wins over B News on simplicity and robustness.  We provide
(in our opinion) everything that's necessary, and avoid the frills that
run up the complexity and decrease reliability.  We have not attempted to
provide every feature anyone can think of, and have no plans to do so
in future either.  (This is one reason why we've stayed out of the news-
reader business, which generally has a bad case of feature-of-the-week
syndrome.)

C News's files are fully compatible with those of B News for any program
that does not read log files and does not inspect the middle field of the
history file closely.  (The one major program that does is "nntp"; current
versions (1.5.8 and later) include our C News support, including a significant
speedup.)  C News complies fully with RFC 1036 (nee RFC 850), the official
definition of news interchange format.

C News is, by intent and *we think* in practice, compatible with B News
at the level of most interfaces to the normal user, which basically means
the semantics and options of "inews".  It is *not* compatible on the
system-administration level, although we think most of the changes are
improvements or worthwhile simplifications.  The "postnews" that we supply
is not compatible with that of B News; it is purely interactive, as news
that is already formatted can simply be fed to "inews -h".

For those who now run one of our ancient pre-alpha versions, many things
have changed, and in particular the four-field history file format is gone.
C News has also changed quite a bit since the alpha release that went out
on Usenet some time ago.

For our beta testers, build and the Makefiles have changed quite a bit but
the software itself needed only fairly trivial fixes.

We know of three things that could still use work in this release:

    1. The documentation could use work, especially for naive customers.
    As it stands, it pretty much assumes a general knowledge of news
    software.

    2. There are a great number of small improvements that could
    be made to the installation process, especially to permit still more
    customization via the "build" program.

    3. The fgetmfs function (in the libc directory) assumes that fgets
    does not alter the buffer beyond the end of the string.  We are not
    sure how portable this is, although it works on all our beta-test
    systems, and may revise fgetmfs someday.

The active file format is the 4-field one that B news introduced midway
through 2.10, with minor additions: an `x' in the 4th field means
``discard articles in this newsgroup'', and `=group' in the 4th field
means ``file articles for this newsgroup under `group' instead''.

The history file format is like B with one exception:  the second field,
which few programs ever look at, now consists of two subfields separated
by a tilde (~).  The first is the arrival date as a decimal number, the
second is the expiry date (if any) as a human-readable date (as emitted by
rnews) or a decimal number (after expire has gotten its hands on it once).
Expire is tolerant of human-readable dates in both those places, but other
things may not be.  The best way to get the history file into the new
format is to rebuild it completely (this is RELATIVELY quick).

The sys file format is like a late-model B news with two extensions.
First, the second field (groups and distributions) may optionally be
split into two subfields (newsgroups and distributions, respectively)
with a slash. This permits solutions to various tricky problems that can
arise in odd situations if it is impossible to tell what's a newsgroup
name and what's a distribution.  Second, there is a new flag in the
third field:  f is like F except that its output has the size
information that the C batcher wants for accurate limiting of batch
size.

The way the news articles themselves are stored is totally unchanged; we
have been unable to think of any changes that are worth the trouble.

There are some new control files in /usr/lib/news, to control the smarter
expire and batcher.  (Old C News sites, note some format changes.)

File organization:  the one change is that programs are now kept mostly
in /usr/lib/newsbin, with /usr/lib/news reserved for control files etc.

B News sites note:  /bin/rnews is now a front end for the input spooler.
The real news-filing program is called relaynews and is not in /bin.

C News is meant to run adequately on a 16-bit machine, although this has
not been tested thoroughly since utzoo became a Sun.

Most (by intent all) of the programs understand seven key environment
variables: NEWSARTS specifies location of articles (default
/usr/spool/news), NEWSCTL specifies location of control files (default
/usr/lib/news), NEWSBIN gives location of programs (default
/usr/lib/newsbin), NEWSUMASK gives the umask to be used in creating
files (default 002), NEWSPATH gives the path used to find "normal" programs
(default /bin:/usr/bin), NEWSMASTER is the address to which problem
reports should be mailed (default usenet), and NEWSCONFIG is the full
pathname of a little file that shell programs can use to pick up local
default settings for all these things (the equivalent for the C programs
is in the C News library) (default /usr/lib/news/bin/config).  The
environment variables override the defaults for testing and for operation
in funny situations.  Note that one or two things (e.g. relaynews), as
distributed, will insist on renouncing setuid privileges if invoked with
these overrides.

Be warned that the simple news reader in
rna has not been gone over very well to make sure that it uses the
standard configuration mechanisms.  Hardwired pathnames may be present there,
and in general the stuff there is not well fitted into our automatic-install
machinery.

See ROADMAP for a run-down on what's where in the distribution.  See
doc/install for how to install it.  You may wish to read notebook/problems,
which discusses common difficulties.  Conf/build is the interactive setup
program that does most of the work, or rather, sets up shell files which,
when run, do most of the work.  Even if your system is odd enough that
you don't want to run the shell files conf/build generates -- doit.bin and
friends -- as is, you are most strongly advised to run conf/build and use
the resulting shell files as guides, rather than trying to "wing it"
yourself.  Getting the library built correctly is *NOT* trivial, because
we try to cater to all 57000 different variants of Unix and there are a lot
of decisions that have to be made.  This is why we supply a 31KB shell
program to generate the configure+compile+install instructions, rather than
just sending a complete pre-cooked recipe embodied in a Makefile:  there are
too many variables affecting how it should be done.

For general background and information on running a news system, we highly
recommend the Nutshell Handbook:

    "Managing UUCP and Usenet", by Tim O'Reilly and Grace Todino,
    O'Reilly & Associates, 1989, ISBN 0-937175-48-X.  This latest
    edition covers C News as well as B News.  It's not perfect but
    it's lots better than nothing.  Inquiries to [e-mail] or
    uunet!ora!nuts.

C News has been tested pretty thoroughly.  We're also thoroughly sick of
it and make no promises that there will ever be another release.  We may,
repeat *may*, provide updates via some appropriate newsgroup (currently
the best choice is "news.software.b", although there is some sentiment for
folding all the subgroups there into just "news.software"; we oppose
creation of "news.software.c" because we don't think there will be enough
traffic to justify a whole newsgroup).

If you've found a problem, we definitely do want to hear about it.  But,
we *do not* want to see 2000 lines of diff listing!  What we want to see
is a concise human-readable description of what the problem is and how,
if at all, you solved it.  If we want the diff listing, we will ask.
Similarly, we are interested in hearing about changes and improvements,
but want to see terse descriptions first.

If you want us to consider changes/fixes/etc, send them to us, don't just
post them to the net.  We don't necessarily read all possibly-relevant
groups.  Only postings from us are officially part of C News.

To send comments, complaints, problem reports, etc., do *not* mail to
Geoff or Henry personally, but to:

    [e-mail]
aka    [e-mail]
aka    utzoo!c-news

(Note that this has changed, c-news used to be on utstat.)

The current C News distribution can currently always be retrieved by
anonymous ftp from ftp.cs.toronto.edu in file pub/c-news/c-news.Z (a shell
archive) or pub/c-news/c-news.tar.Z (a tar archive) and the complete set
of patches can also be found on ftp.cs.toronto.edu in the directory
pub/c-news/patches.  FTP during our peak hours (12h00-17h00 Eastern) is
not encouraged.

                    Geoff Collyer
                    Henry Spencer