[Xymon] xymond_filestore - appending to files?

Hi John,

I would like to use the 'xymond_filestore' command to append to files when receiving information from a 'data' channel.

[snip description of how it works]

As the man-page says, "[xymond_filestore] receives xymond messages from a xymond channel via stdin, and stores these in the filesystem in a manner that is compatible with the Big Brother daemon, bbd."

So it's a module that was written for compatibility with the way Big Brother works, and it isn't really intended for anything but that one purpose. And to be honest, I no longer remember the exact details of how Big Brother processed these messages; the last time I had a look at how BB worked was almost 10 years ago.

Going back to your original request: Having the data from "data" messages appended to a file. Like the other Xymon channels, information sent via the "data" channel is easily available to any server-side module you can think of. Just run a task out of tasks.cfg that picks up the data-channel messages:

xymond_channel --channel=data mymodule.pl

and then write your "mymodule.pl" program to do what you like. It doesn't have to be Perl; feel free to use whatever scripting tool you fancy. I just used Perl as an example, because there is a little Perl program included with Xymon that shows how to do that - look at the xymond/xymond_rootlogin.pl program. The header-line of a "data" message is different from the "client" header that rootlogin.pl handles, but not very much so you should be able to work it out. You can see the messages by running

xymoncmd xymond_channel --channel=data cat

while logged in as the Xymon user.

And feel free to use xymond_filestore as a starting point for writing your own data-handling program :-)

Regards, Henrik