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FILECHAN(8) InterNetNews Documentation FILECHAN(8)


filechan - File-writing backend for INN


filechan [-d directory] [-f num-fields] [-m map-file] [-p pid-file]


filechan reads lines from standard input and copies the initial fields in each line to the files named by the remaining fields on the line. filechan is intended to be called by innd 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.)

The 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 and do not contain any whitespace. The default number of initial fields is one.

For each line of input, filechan writes the initial fields, separated by a space 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 owning 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 have not been implemented and are not necessarily needed for the way filechan is called and works; mv(1) followed by sleep(1) for a couple of seconds is sufficient.


By default, filechan writes its output into the pathoutgoing directory. This flag may be used to specify a directory the program should change to before starting.
This flag specifies a different number of initial fields.
A map file may be specified by using this 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.
If this flag is used, filechan will write a line containing its process ID (in text) to the specified file.


If filechan is invoked with "-f 2" and given the following input: <> foo uunet <> uunet munnari
    comp.sources.unix <> foo uunet munnari

then the file foo in pathoutgoing will have these lines: <>
    comp.sources.unix <>

the file munnari in pathoutgoing will have these lines: <>
    comp.sources.unix <>

and the file uunet in pathoutgoing will have these lines: <> <>
    comp.sources.unix <>

Using filechan this way can be done in newsfeeds with for instance:

    filechan!:*:Tc,WGm*:<pathbin>/filechan -f 2

It will generate the examples above. See the "W" flag in newsfeeds(5) for how to parameter the output.


Written by Robert Elz <>, flags added by Rich $alz <>. Rewritten into POD by Julien Elie.


buffchan(8), newsfeeds(5).

2022-01-23 INN 2.6.5