buffchan - buffered file-writing backend for InterNetNews


   buffchan  [  -b  ]  [  -c  lines ] [ -C seconds ] [ -d directory ] [ -f
   fields ] [ -m map ] [ -p pidfile ] [ -l lines ] [ -L seconds ] [ -r ] [
   -s file_format ] [ -u ]


   Buffchan  reads  lines from standard input and copies certain fields in
   each line into files named by other fields within the  line.   Buffchan
   is intended to be called by innd(8) as an exploder feed.


   -b     Once  buffchan  opens  a  file it keeps it open.  The input must
          therefore never specify  more  files  than  can  the  number  of
          available  descriptors  can  keep  open.   If the ``-b'' flag is
          used, the program will allocate a buffer and attach  it  to  the
          file using setbuf(3).

   -c     If  the  ``-c'' flag is used with a number n, then buffchan will
          close, and re-open, a file after every n lines are written to  a

   -C     Similarly, the ``-C'' flag may be used to specify that all files
          should be closed and re-opened every n seconds.

   -d     The ``-d'' flag may be used to specify a directory  the  program
          should  change  to  before starting.  If this flag is used, then
          the default for the ``-s''  flag  is  changed  to  be  a  simple

   -f     Buffchan  input  is  interpreted  as  a set of lines.  Each line
          contains a  fixed  number  of  initial  fields,  followed  by  a
          variable  number  of  filename fields.  All fields in a line are
          separated by whitespace.  The default number of  initial  fields
          is  one;  the  ``-f''  flag  may  be used to specify a different
          number of fields.  See filechan(8) for an example.

   -p     If the ``-p'' flag is  used,  the  program  will  write  a  line
          containing its process ID (in text) to the specified file.

   -l     If  the  ``-l'' flag is used with a number n, then buffchan will
          call fflush(3) after every n lines are written to a file.

   -L     If the ``-L'' flag is used with a number n, then all files  will
          be flushed every n seconds.

   -r     By   default,   the   program   sets   its   standard  error  to
          /var/log/news/errlog.  To suppress  this  redirection,  use  the
          ``-r'' flag.

   -s     After  the  initial fields, each remaining field names a file to
          write.  The ``-s'' flag may be used to specify a  format  string
          that maps the field to a file name.  This is a sprintf(3) format
          string which should have a single ``%s'' parameter which will be
          given      the      field.      The     default     value     is
          /var/spool/news/out.going/%s.  See the description of this  flag
          in filechan(8).

   -u     If  the ``-u'' flag is used, the program will request unbuffered

   Buffchan can be invoked as an exploder  feed  (see  newsfeeds(5)).   As
   such,  if a line starts with an exclamation point it will be treated as
   a command.  There are three commands, described below:

   flush  The ``flush''  command  closes  and  re-opens  all  open  files;
          ``flush xxx''  which flushes only the specified site.  These are
          analogous to  the  ctlinnd(8)  ``flush''  command,  and  can  be
          achieved  by doing a ``send "flush xxx"'' command.  Applications
          can tell that the ``flush'' has completed by renaming  the  file
          before  issuing  the command; buffchan has completed the command
          when the original filename re-appears.

          Buffchan also changes the access permissions of  the  file  from
          read-only  for  everyone to read-write for owner and group as it
          flushes or closes each output file.  It will  change  the  modes
          back to read-only if it re-opens the same file.

   drop   The  ``drop'' command is similar to the ``flush'' command except
          that any files are not re-opened.  If given  an  argument,  then
          the  specified site is dropped, otherwise all sites are dropped.
          (Note that the site  will  be  restarted  if  the  input  stream
          mentions  the  site.)   When  a ctlinnd ``drop site'' command is
          sent, innd will automatically forward the command to buffchan if
          the site is a funnel that feeds into this exploder.  To drop all
          sites, use the ctlinnd ``send buffchan-site drop'' command.

          The map file (specified with the ``-m'' flag) is reloaded.


   Written by Rich $alz <rsalz@uunet.uu.net> for  InterNetNews.   This  is
   revision 1.11, dated 1996/10/29.


   ctlinnd(8), filechan(8), innd(8), newsfeeds(5).



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