inotify

This example demonstrates how to initialize Inotify, define a callback to handle different event types using bitwise operators, and set up watches on specific paths.

var Inotify = require('inotify').Inotify;
var inotify = new Inotify(); //persistent by default, new Inotify(false) //no persistent

var data = {}; //used to correlate two events

var callback = function(event) {
    var mask = event.mask;
    var type = mask & Inotify.IN_ISDIR ? 'directory ' : 'file ';
    if (event.name) {
        type += ' ' + event.name + ' ';
    } else {
        type += ' ';
    }

    if (mask & Inotify.IN_ACCESS) {
        console.log(type + 'was accessed ');
    } else if (mask & Inotify.IN_MODIFY) {
        console.log(type + 'was modified ');
    } else if (mask & Inotify.IN_OPEN) {
        console.log(type + 'was opened ');
    } else if (mask & Inotify.IN_CLOSE_NOWRITE) {
        console.log(type + ' opened for reading was closed ');
    } else if (mask & Inotify.IN_CLOSE_WRITE) {
        console.log(type + ' opened for writing was closed ');
    } else if (mask & Inotify.IN_ATTRIB) {
        console.log(type + 'metadata changed ');
    } else if (mask & Inotify.IN_CREATE) {
        console.log(type + 'created');
    } else if (mask & Inotify.IN_DELETE) {
        console.log(type + 'deleted');
    } else if (mask & Inotify.IN_DELETE_SELF) {
        console.log(type + 'watched deleted ');
    } else if (mask & Inotify.IN_MOVE_SELF) {
        console.log(type + 'watched moved');
    } else if (mask & Inotify.IN_IGNORED) {
        console.log(type + 'watch was removed');
    } else if (mask & Inotify.IN_MOVED_FROM) {
        data = event;
        data.type = type;
    } else if (mask & Inotify.IN_MOVED_TO) {
        if ( Object.keys(data).length &&
            data.cookie === event.cookie) {
            console.log(type + ' moved to ' + data.type);
            data = {};
        }
    }
}

var home_dir = {
    path:      '/home/camilo',
    watch_for: Inotify.IN_OPEN | Inotify.IN_CLOSE,
    callback:  callback
};

var home_watch_descriptor = inotify.addWatch(home_dir);

var home2_dir = {
    path:      '/home/bob',
    watch_for: Inotify.IN_ALL_EVENTS,
    callback:  callback
};

var home2_wd = inotify.addWatch(home2_dir);

The Inotify class provides methods to manage file system watches.

• new Inotify([persistent]): Creates a new instance. Defaults to persistent mode. Pass false for non-persistent mode.
• addWatch(arg): Adds a watch for a file or directory. Returns a watch descriptor (integer).
  • arg.path: Path to monitor.
  • arg.watch_for: An OR'ed set of events (e.g., Inotify.IN_ALL_EVENTS). Defaults to Inotify.IN_ALL_EVENTS.
  • arg.callback: Function receiving the event object.
• removeWatch(watch_descriptor): Removes a watch. Returns true if successful, false otherwise. Removing a watch triggers an Inotify.IN_IGNORED event.
• close(): Removes all watches and closes the inotify file descriptor. Returns true if successful, false otherwise.

Note: Monitoring of directories is not recursive. To monitor subdirectories, you must create additional watches for each subdirectory.

var Inotify = require('inotify').Inotify;
var inotify = new Inotify(); // persistent by default

var wd = inotify.addWatch({
    path: '.',
    watch_for: Inotify.IN_ALL_EVENTS,
    callback: function (event) {
        console.log('Event received:', event);
    }
});

// Later, remove the watch
inotify.removeWatch(wd);

Use these constants to specify which events to monitor in the watch_for option of addWatch() or to check the event.mask in your callback.