NEWSDB(5)NEWSDB(5)NAMEnewsdb - USENET network news database: article tree, history, active,
active.times
DESCRIPTION
Each news article is stored in a separate file with one or more links,
each a numeric name in a directory under /var/news corresponding to a
newsgroup the article is (cross-)posted to. For example, an article
posted to comp.unix.wizards might be stored in /var/news/comp/unix/wiz‐
ards/4867.
The file /var/lib/news/active defines the locally-valid news groups and
contains one line per group. Each line consists of four blank-sepa‐
rated fields: newsgroup name, highest local article number assigned,
lowest local article number in use (approximately), and a flag. Both
article-number fields are at least five digits wide. (Some older news
software may expect exactly five digits.) The current flag values are
y (a normal unmoderated group), n (like y but local postings disal‐
lowed), m (a normal moderated group), x (a locally-disabled group, no
articles will be filed here), and = (followed by the real group under
which to file articles in this group; articles are treated exactly as
if their Newsgroups: header specified the real group instead of the
original one; highest and lowest fields are ignored).
The file /var/lib/news/active.times is an extension of the active file
that records the arrival of new newsgroups by time and creator. When a
new newsgroup is created, the group name, time of group creation (as
seconds since January 1, 1970, 00:00, GMT), and mail address of the
creator are appended as a single line. The file must always be sorted
in increasing order of the creation-time field. The news software only
appends to the file, which normally suffices to ensure this. An ini‐
tial active.times for already existing newsgroups, with all times equal
to the time of its creation and all creators ``unknown'', can be built
using act.to.times (see newsmaint(8CN)). Active.times provides a quick
way for newsreaders to tell when new groups have arrived, without weird
heuristics and expensive schemes like storing old lists of newsgroups
and comparing them to the active file.
The file /var/lib/news/history contains one line for each article
received. Each line consists of three tab-separated fields: a Message-
ID:, a complex middle field, and the list of links to this article.
The links are separated by blanks and are given as pathnames relative
to /var/news, except that all the `/'s except the last one (between the
last component of the newsgroup name and the numeric article name) are
replaced by `.'s. If an article has been expired or cancelled without
being seen first, the list of links and the tab before it are omitted.
The middle history field potentially has several subfields separated by
tilde (~). Currently only three are defined: the arrival date, the
expiry date, and an optional article size in bytes. The arrival date
is a time_t (see time(2); in Unix a time_t is a count of seconds since
the GMT beginning of 1970) expressed as a decimal integer. The expiry
date is another decimal time_t, or the contents of the Expires: header
from the message, or `-' indicating that there was no explicit expiry
date given.
There are also index files to permit rapid history lookup by message-
id, typically called /var/lib/news/history.dir and /var/lib/news/his‐
tory.pag.
Also usually present now are overview files, one per newsgroup; see
newsoverview(5) for more detail on them.
EXAMPLES
A trivial active file.
control 0000600006 600004 y
junk 0000000076 00074 y
comp.org.usrgroup 0000000006 00004 y
talk.bizarre 0000296123 292136 n
comp.sys.sun 0000050175 50173 m
list.sun-spots 0000000076 00076 =comp.sys.sun
comp.os.vms 0000000000 00000 x
A trivial history file.
<3451@hcr.UUCP> 581905588~- comp.text/1317 comp.sources.wanted/4200
<9383@alice.UUCP> 611934511~-
FILES
/var/news/news/group/1234
/var/lib/news/active
/var/lib/news/active.times
/var/lib/news/history
/var/lib/news/history.dir
/var/lib/news/history.pag
SEE ALSOdbz(1), readnews(1CN), rn(1), dbz(3Z), getabsdate(3), news(5),
newsoverview(5), newssys(5), expire(8CN), newshist(8CN), news‐
maint(8CN), relaynews(8CN), newsinvaders(9.1)
HISTORY
Active.times invented by Mark Moraes and Geoff Collyer as part of the C
News project.
BUGS
Reader implementors are warned that the various files mentioned here—
the active file, the history file, the article tree itself, and the
overview files—in general are not updated perfectly simultaneously.
Nor are they necessarily updated in a predictable order.
18 Nov 1994 NEWSDB(5)
