Provided by: inn_1.7.2debian-30_i386
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
-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
-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 <firstname.lastname@example.org> for InterNetNews. This is
revision 1.11, dated 1996/10/29.
ctlinnd(8), filechan(8), innd(8), newsfeeds(5).