inotify | Linuxaria

Incron – a cron based on FS events

Feb 272011

In a former article we saw something about Inotify.

inotify is a Linux kernel subsystem that acts to extend filesystems to notice changes to the filesystem, and report those changes to applications. It replaces an earlier facility, dnotify, which had similar goals.

Last time I focused on the functionality of inotifywait command which can be used by shell to wait for a certain event and then perform other functions, but today we will see some uses of incron.

This program is an “inotify cron” system. It consists of a daemon and a table manipulator. You can use it a similar way as the regular cron. The difference is that the inotify cron handles filesystem events rather than time periods. Continue reading »

Introduction to inotify

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Nov 262010

The original developers of inotify were John McCutchan, Robert Love and Amy Griffis. It has been included in the mainline Linux kernel from release 2.6.13 (June 18, 2005), and could be compiled into 2.6.12 and possibly earlier releases by use of a patch.

One major use is in desktop search utilities like Beagle, where its functionality permits reindexing of changed files without scanning the filesystem for changes every few minutes, which would be very inefficient. By being told that a file has changed directly by the kernel, rather than actively looking, Beagle and such utilities can achieve change-to-reindexing times of only about a second.