prunehistory - remove file names from Usenet history file


   prunehistory [ -f filename ] [ -p ] [ input ]


   Prunehistory  modifies  the history(5) text file to ``remove'' a set of
   filenames from it.  The filenames are removed by overwriting them  with
   spaces, so that the size and position of any following entries does not

   Prunehistory reads the named input file, or standard input if  no  file
   is given.  The input is taken as a set of lines.  Blank lines and lines
   starting with a number sign (``#'') are ignored.  All other  lines  are
   should consist of a Message-ID followed by zero or more filenames.

   The  Messge-ID is used as the dbz(3) key to get an offset into the text
   file.  If no filenames are  mentioned  on  the  input  line,  then  all
   filenames in the text are ``removed.''  If any filenames are mentioned,
   they are converted into the history file notation.  If they  appear  in
   the line for the specified Message-ID then they are removed.

   Since innd(8) only appends to the text file, prunehistory does not need
   to have any interaction with it.


   -p     Prunehistory will normally complain  about  lines  that  do  not
          follow the correct format.  If the ``-p'' flag is used, then the
          program will silently print any invalid lines  on  its  standard
          output.    (Blank  lines  and  comment  lines  are  also  passed
          through.)  This can be useful when prunehistory  is  used  as  a
          filter for other programs such as reap.

   -f     The  default  name of the history file is /var/lib/news/history;
          to specify a different name, use the ``-f'' flag.


   It is a good idea to delete purged entries and rebuild the dbz database
   every so often by using a script like the following:

          ctlinnd throttle "Rebuilding history database"
          cd /var/lib/news
          awk 'NF > 2 {
               printf "%s\t%s\t%s", $1, $2, $3;
               for (i = 4; i <= NF; i++)
                    printf " %s", $i;
               print "\n";
          }' <history >history.n
          if makehistory -r -f history.n ; then
              mv history.n history
              mv history.n.pag history.pag
              mv history.n.dir history.dir
              echo 'Problem rebuilding history; old file not replaced'
          ctlinnd go "Rebuilding history database"

   Note that this keeps no record of expired articles.


   Written  by  Rich  $alz <> for InterNetNews.  This is
   revision 1.9, dated 1996/10/29.


   dbz(3), history(5), innd(8).



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