Dumb Linux Question.

[swestrup]

Speaking of Linux and tools and stuff, I (vaguely) remember reading, years ago, about a method for setting up a spool directory such that any time a file was dropped into the directory, a daemon would immediately read the file and process it. I think there was also some sort of business involving named pipes, but I don't really recall. This may have been because the handling daemon was in another box than the spool directory -- IIRC this was part of a lan-wide printing setup.

Anyway, fast-forward to today, and I'm thinking of putting in 'Retrain' directories in all of the mail accounts on my mail server. Anytime the mail headers misclassify something as spam or nonspam, you simply drop the misclassified mail into the retrain directory, and it is automagically removed and trained as being in the opposite class as its headers suggest, and then re-delivered through the mail-filter system.

Now, clearly I can do all this with a cron task, but I want snappier responses. Ideally, there should only be a few seconds delay between dropping stuff into the retrain directory and getting it re-delivered correctly. Does anyone have any good ideas about how one goes about setting this up these days? If its any help, I have FAM up and running on the system (although I don't really know how it works.)

Comments

[swestrup]

Well, I've found famd and dnotify, both of which use a new kernel signalling method that lets you register a signal handler for individual file and/or directory changes. The problem is, there's a whole bunch of coding needed to take this from being a simple daemon to being what I want, which is a user-controllable daemon to handle calling of arbitrary programs upon file change, and doing so in a safe and sane manner.

Oh, well. I may just end up kludging something together in perl.