MAN page from RedHat Other leafnode-1.6.2-2.i386.rpm

fetch

Section: Maintenance Commands (8)
Updated: 30 Oct 1995
Index

NAME

fetch - fetch news via NNTP

SYNOPSIS

fetch [-v] [-x number] [-l] [-n] [-f]

DESCRIPTION

Leafnodeis a USENET package intended for small sites, where there are fewusers and little disk space, but where a large number of groups isdesired.

The design ofleafnodeis intended to self-repair after problems, and to require nomanual maintenance.

Fetchis the program which submits and retrieves new articles to or from theupstream NNTP server.

OPTIONS

-v: Be verbose. A maximum of four-vcan be used (the more v, the more verbose):
-v: Warn about non-critical errors.
-vv: Be verbose whenever a group command occurs.
-vvv: Be verbose whenever an article command occurs.
-vvvv: For debugging purposes. Don't expect the additional output to make sense.
-x number: Gonumberarticles back and try to re-fetch what's missing. Chiefly used fordebugging purposes.
-l: Don't use supplementary servers (-lis supposed to mean "local"). This does speed up the operation quite abit.
-n: Don't unlink files in theinteresting.groupsdirectory. This avoids automatic unsubscription of newsgroups.
-f: Force rereading of whole active file from all upstream servers. This isusually occurring only very infrequently because it takes a long time.

FILES AND CONFIGURATION

Seeleafnode(8)for the list of files affected, and for information on configuringfetch.

ALGORITHM

Here is a brief description of whatfetchdoes.

First, after connecting to the upstream NNTP server,all articles in/var/spool/news/out.goingare posted using POST. If a posting fails, that article is moved to/var/spool/news/failed.postingswhich an administrator has to clean up once in a while. Moving a fileback to/var/spool/news/out.going is sufficient to resubmit it.

Second, the upstream server's list of newsgroups (obtained using LISTACTIVE and LIST NEWSGROUPS) is merged intoleafnode's(this step is most often optimized away).

Third,fetchiterates over the list of newsgroups, performing a GROUP, an XHDRMessage-ID and a number of HEAD and BODY commands for each group whichhas been read recently.

NOTES

Fetchdoes not use NEWNEWS or XOVER. NEWNEWS is not used because it isoften very expensive, XOVER is not used because the information itobtains is also present in the article headers.

After some experiments, I decided that it was better to fetch all thearticles in a group than to optimize away some; users would complaintoo loudly when the optmizer guessed wrongly.Leafnodeis not intended to be all things to all men, and I have sacrificed theability to read news from two upstream servers. (There is some supportfor it, but it is incomplete and undocumented at the time of writing.)

Fetchhappens to support local groups, even though the rest ofleafnodedoesn't.

The only way to control what newsgroups are accessible to local usersis to control what the upstream server letsfetchread, and that will not keep out all crossposts (endemic in e.g. thealt.sex groups). If your site is big enough that you need to controlnewsgroup access, consider using a news server which is designed for abig site.

Fetchsets its real and effective uid to "news", because almost all of theproblems I have had withleafnodeare due to files which aren't writable for user news.

BUGS

Fetchignores the "Supersedes" and "Also-Cancel" headers. This needs to befixed, or news.answers will suffer.

Never deletes a group from the list of active newgroups.

AUTHOR AND LICENCE

Modified by Cornelius Krasel <kraselAATTwpxx02.toxi.uni-wuerzburg.de>,Markus Enzenberger <enzAATTcip.physik.uni-muenchen.de>and Randolf Skerka <rskerkaAATTmetronet.de>.Copyright of the modifications 1997, 1998.

Use, modification and distribution is allowed without limitation,warranty, or liability of any kind.

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