filechan - file-writing backend for InterNetNews

filechan [ -d directory ] [ -f num_fields ] [ -m mapfile ] [ -p pidfile ]

Filechan reads lines from standard input and copies certain fields in each line into files named by other fields within the line. Filechan is intended to be called by innd(8) as a channel feed. (It is not a full exploder and does not accept commands; see newsfeeds(5) for a description of the difference, and buffchan(8) for an exploder program.)

Filechan 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 whitespace. The default number of initial fields is one.

For each line of input, filechan writes the initial fields, separated by whitespace and followed by a newline, to each of the files named in the filename fields. When writing to a file, filechan opens it in append mode and tries to lock it and change the ownership to the user and group who owns the directory where the file is being written.

Because the time window in which a file is open is very small, complicated flushing and locking protocols are not needed; a mv(1) followed by a sleep(1) for a couple of seconds is sufficient.

-f num_fields

The ``-f'' flag may be used to specify a different number of initial fields.

-d directory

By default, filechan writes its output into the directory <pathoutgoing in inn.conf>. The ``-d'' flag may be used to specify a directory the program should change to before starting.

-p pidfile

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

-m mapfile

A map file may be specified by using the ``-m'' flag. Blank lines and lines starting with a number sign (``#'') are ignored. All other lines should have two host names separated by a colon. The first field is the name that may appear in the input stream; the second field names the file to be used when the name in the first field appears. For example, the following map file may be used to map the short names used in the example below to the full domain names:

# This is a comment
uunet:news.uu.net
foo:foo.com
munnari:munnari.oz.au

If filechan is invoked with ``-f 2'' and given the following input:

news/software/b/132 <1643@munnari.oz.au> foo uunet
news/software/b/133 <102060@litchi.foo.com> uunet munnari
comp/sources/unix/2002 <999@news.foo.com> foo uunet munnari

Then the file foo will have these lines:

news/software/b/132 <1643@munnari.oz.au>
comp/sources/unix/2002 <999@news.foo.com>

news/software/b/133 <102060@litchi.foo.com>
comp/sources/unix/2002 <999@news.foo.com>

news/software/b/132 <1643@munnari.oz.au>
news/software/b/133 <102060@litchi.foo.com>
comp/sources/unix/2002 <999@news.foo.com>

Written by Robert Elz <kre@munnari.oz.au>, flags added by Rich $alz <rsalz@uunet.uu.net>.

buffchan(8), inn.conf(5), innd(8), newsfeeds(5).