NAME

     history - record of  current  and  recently  expired  Usenet
     articles

DESCRIPTION

     The file /news/etc/history keeps a record  of  all  articles
     currently  stored  in the news system, as well as those that
     have been received but since expired.  In a typical  produc-
     tion environment, this file will be many megabytes.

     The file consists of text lines.  Each line  corresponds  to
     one  article.  The file is normally kept sorted in the order
     in which articles are  received,  although  this  is  not  a
     requirement.   Innd(8) appends a new line each time it files
     an article, and expire(8) builds a new version of  the  file
     by removing old articles and purging old entries.

     Each line consists of two or three  fields  separated  by  a
     tab, shown below as \t:
          <Message-ID>   \t   date
          <Message-ID>   \t   date   \t   files

     The Message-ID field is the value of the article's  Message-
     ID header, including the angle brackets.

     The date field consists of three sub-fields separated  by  a
     tilde.   All  sub-fields  are the text representation of the
     number of seconds since the epoch - i.e., a time_t; see get-
     timeofday(2).   The first sub-field is the article's arrival
     date.  If copies of the article are still present  then  the
     second  sub-field  is  either  the  value  of  the article's
     Expires header, or a hyphen if no expiration date was speci-
     fied.   If  an article has been expired then the second sub-
     field will be a hyphen.  The third sub-field is the value of
     the  article's  Date  header, recording when the article was
     posted.

     The files field is a set of entries separated by one or more
     spaces.  Each entry consists of the name of the newsgroup, a
     slash, and the article number.  This field is empty  if  the
     article has been expired.

     For example, an article  cross-posted  to  comp.sources.unix
     and comp.sources.d that was posted on February 10, 1991 (and
     received three minutes later), with an  expiration  date  of
     May  5,  1991,  could  have  a history line (broken into two
     lines for display) like the following:
          <312@litchi.foo.com>  \t  666162000~673329600~666162180  \t
              comp.sources.unix/1104 comp.sources.d/7056

     In addition to the text file, there is  a  dbz(3z)  database
     associated with the file that uses the Message-ID field as a
     key to determine the offset in the text file where the asso-
     ciated   line  begins.   For  historical  reasons,  the  key
     includes the trailing \0 byte (which is not  stored  in  the
     text file).

HISTORY

     Written by Rich $alz <rsalz@uunet.uu.net> for  InterNetNews.
     This is revision 1.12, dated 1996/09/06.

SEE ALSO

     dbz(3z), expire(8), innd(8), news-recovery(8).