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buffchan - buffered file-writing backend for InterNetNews
SYNOPSIS
buffchan [ -b ] [ -c lines ] [ -C seconds ] [ -d directory ] [ -f num_fields ] [ -m map ] [ -p pidfile ] [ -l
lines ] [ -L seconds ] [ -r ] [ -s filename_format ] [ -u ]
DESCRIPTION
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.
OPTIONS
-b Once buffchan opens a file it keeps it open. The input must therefore never specify more files than 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 lines
If the ``-c flag is used, buffchan will close, and re-open, a file after every lines lines are written
to a file.
-C seconds
Similarly, the ``-C flag may be used to specify that all files should be closed and re-opened every sec-
onds seconds.
-d directory
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 ``%s.
-f num_fields
Buffchan input is interpreted as a sequence 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 whites-
pace. The default number of initial fields is one; the ``-f flag may be used to specify a different
number of fields.
-m map Map files specify short names as aliases for domain names; see filechan(8) for details and an example.
-p pidfile
If the ``-p flag is used, the program will write a line containing its process ID (in text) to the spec-
ified file.
-l lines
If the ``-l flag is used, buffchan will call fflush(3) after every lines lines are written to a file.
-L seconds
If the ``-L flag is used, all files will be flushed every n seconds.
-r By default, the program sends its error messages to <pathlog in inn.conf>/errlog. To suppress this redi-
rection and send error messages to standard error, use the ``-r flag.
-s filename_format
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 contents of a non-initial field. The
default value is <pathoutgoing in inn.conf>/%s. See the description of this flag in filechan(8).
-u If the ``-u flag is used, the program will request unbuffered output.
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. If
<$ac_cv_func_fchmod in config.cache> is ``yes, then 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 no files are 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 for sites listed as funnels feeding into this exploder.
To drop all sites, use the ctlinnd ``send buffchan-site drop command.
readmap
The map file (specified with the ``-m flag) is reloaded.
HISTORY
Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews. This is revision 1.8, dated 2002/12/03.
RELATED
ctlinnd(8), filechan(8), inn.conf(5), innd(8), newsfeeds(5).
CATEGORY