EXPIRE.CTL(5) InterNetNews Documentation EXPIRE.CTL(5)
NAME
expire.ctl - Configuration file for article expiration
DESCRIPTION
The file pathetc/expire.ctl is the default configuration file for
expire and expireover, which read it at start-up. It serves two
purposes: it defines how long history entries for expired or rejected
articles are remembered, and it determines how long articles stored on
the server are retained.
Normally, if all of the storage methods used by the server are self-
expiring (such as CNFS), all lines except the "/remember/" setting
(described below) are ignored. This can be changed with the -N option
to expire or expireover.
Blank lines and lines beginning with a number sign ("#") are ignored.
All other lines should be in one of two formats. The order of the file
is significant, and the last matching entry will be used.
The first format specifies how long to keep history entries for
articles that aren't present in the news spool. These are articles
that have either already expired, or articles which the server rejected
(when remembertrash is set to true in inn.conf). There should be one
and only one line in this format, which looks like:
/remember/:<days>
where <days> is a decimal number that specifies the minimum number of
days a history record for a given message-ID is retained (from its
original posting time), regardless of whether the article is present in
the spool. (History entries for articles still present in the spool
are always retained.)
The primary reason to retain a record of old articles is in case a peer
offers old articles that were previously accepted but have already
expired. Without a history record for such articles, the server would
accept the article again and readers would see duplicate articles.
Articles older than a certain number of days won't be accepted by the
server at all (see artcutoff in inn.conf(5) and the -c flag in
innd(8)), and this setting should probably match that time period to
ensure that the server never accepts duplicates. As the default value
for artcutoff is 10 days, it means that "/remember/" should be set to
11 days in order to take into account articles whose posting date is
one day into the future.
Most of the lines in this file will be in the second format, which
consists of either four or five colon-separated fields:
<pattern>:<flag>:<min>:<default>:<max>
if groupbaseexpiry is true in inn.conf (the default), and otherwise:
<classnum>:<min>:<default>:<max>
All lines must be in the correct format given the current setting of
groupbaseexpiry, and therefore the two formats cannot co-exist in the
same file.
Normally, a rule matches a newsgroup through the combination of the
<pattern> and <flag> fields. <pattern> is a uwildmat(3)-style pattern,
specifying the newsgroups to which the line is applied. Note that the
last matching entry will be used, so general patterns (such as defaults
for all groups where <pattern> is "*") should appear at the beginning
of the file before more specific settings.
The <flag> field can be used to further limit newsgroups to which the
line applies, and should be chosen from the following set:
M Only moderated groups
U Only unmoderated groups
A All groups
X Remove the article from all groups it appears in
One of "M", "U", or "A" must be specified. "X" should be used in
combination with one of the other letters, not by itself.
An expiration policy is applied to every article in a newsgroup it
matches. There is no way to set an expiration policy for articles
crossposted to groups you don't carry that's different than other
articles in the same group. Normally, articles are not completely
deleted until they expire out of every group to which they were posted,
but if an article is expired following a rule where <flag> contains
"X", it is deleted out of all newsgroups to which it was posted
immediately.
If groupbaseexpiry is instead set to false, there is no <pattern> and
<flag> field and the above does not apply. Instead, there is a single
<classnum> field, which is either a number matching the storage class
number specified in storage.conf or "*" to specify a default for all
storage classes. All articles stored in a storage class will be
expired following the instructions in the line with a matching
<classnum>, and when articles are expired, they're always removed from
all groups to which they were posted.
The remaining three fields are the same in either format, and are used
to determine how long an article should be kept from its original
arrival time (unless the -p flag is passed to expire(8) or
expireover(8), in which case its original posting time is used). Each
field should be either a decimal number of days (fractions like 8.5 are
allowed, but remember that articles are only removed when expire or
expireover is run, normally once a day by news.daily) or the word
"never".
The middle field, <default>, will be used as the expiration period for
most articles. The other two fields, <min> and <max>, only come into
play if the article requests a particular expiration date with an
Expires: header. Articles with an Expires: header will be expired at
the date given in that header, subject to the constraints that they
will be retained at least <min> days and no longer than <max> days.
If <min> is set to "never", no article matching that line will ever be
expired. If <default> is set to "never", no article matching that line
without an explicit Expires: header will ever be expired. If <max> is
set to "never", Expires: headers will be honored no matter how far into
the future they are.
One should think of the fields as a lower bound, the default, and an
upper bound. Since most articles do not have an Expires: header, the
second field is the most important and most commonly applied.
Articles that do not match any expiration rule will not be expired, but
this is considered an error and will result in a warning. There should
always be a default line (a line with a <pattern> of "*" and <flag> of
"A", or a line with a <classnum> of "*"), which can explicitly state
that articles should never expire by default if that's the desired
configuration. The default line should generally be the first line of
the file (except for "/remember/") so that other expiration rules can
override it.
It is often useful to honor the Expires: header in articles, especially
those in moderated groups. To do this, set <min> to zero, <default> to
whatever normal expiration you wish, and <max> to "never" or some large
number, like 365 days for a maximum article life of a year.
To ignore any Expires: header, set all three fields to the same value.
EXAMPLES
When groupbaseexpiry is true (the default):
# Keep expired article history for 11 days, matching artcutoff plus one.
/remember/:11
# Most articles stay for two weeks, ignoring Expires: headers.
*:A:14:14:14
# Accept Expires: headers in moderated groups for up to a year and
# retain moderated groups for a bit longer.
*:M:1:30:365
# Keep local groups for a long time and local project groups forever.
example.*:A:1:90:90
example.project.*:A:never:never:never
When groupbaseexpiry is false, for class-based expiration:
# Keep expired article history for 11 days, matching artcutoff plus one.
/remember/:11
# Set a default expiration of seven days and honour Expires: headers
# within reasonable limits.
*:1:7:35
# Class 0 is retained for two weeks and honor Expires: headers
# within reasonable limits.
0:1:14:65
HISTORY
Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews. Converted
to POD by Russ Allbery <eagle@eyrie.org>.
$Id: expire.ctl.pod 9767 2014-12-07 21:13:43Z iulius $
SEE ALSO
expire(8), expireover(8), inn.conf(5), innd(8), news.daily(8),
storage.conf(5), uwildmat(3).
INN 2.6.4 2015-09-20 EXPIRE.CTL(5)