history - record of current and recently expired Usenet articles
The file <pathdb in inn.conf>/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 production 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:
[Hash] \t date
[Hash] \t date \t token
The Hash field is the ASCII representation of the hash of the Message-
ID header. This is directly used for the key of the dbz(3).
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 gettimeofday(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 specified. 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 token field is a token of the article. This field is empty if the
article has been expired.
For example, an article whose Message-ID was
<email@example.com>, posted on 26 Aug 1999 08:02:34 GMT and
recieved at 26 Aug 1999 08:06:54 GMT, could have a history line (broken
into three lines for display) like the following:
In addition to the text file, there is a dbz(3) database associated
with the file that uses the Message-ID field as a key to determine the
offset in the text file where the associated line begins. For
historical reasons, the key includes the trailing \0 byte (which is not
stored in the text file).
Written by Rich $alz <firstname.lastname@example.org> for InterNetNews. This is
revision 3782, dated 2000-08-17.
dbz(3), expire(8), inn.conf(5), innd(8), makehistory(8).