Inotify lets applications subscribe to change notifications in the filesystem. Mike Schilli uses the cross-platform fsnotify library to instruct a Go program to detect what’s happening.
In a file manager, have you ever observed how newly created files by other applications immediately appear in the displayed directory and wondered how this works? As continuous querying of the filesystem is out of the question for performance reasons, these applications use the Linux filesystem’s inotify interface instead.
Operating systems implement the mechanism in different ways: Linux uses inotify, the Mac uses kqueue, and Windows comes with an unpronounceable extra. Fortunately, the Go library fsnotify on GitHub abstracts this proliferation to create a simple interface. This means that programmers only need to write their applications once to cover all platforms.
About 15 years ago, I wrote an article on this topic in my regular column . At the time I used Perl, and the article relied on FUSE, a special filesystem. Today filesystem notifications are part of the standard.
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