inotify_add_watch
inotify_queue_len
Inotify Functions
PHP Manual

# inotify_init

Initialize an inotify instance

### Description

resource inotify_init ( void )

Initialize an inotify instance for use with inotify_add_watch

### Return Values

A stream resource or `FALSE` on error.

### Examples

Example #1 Example usage of inotify

`<?php
// Open an inotify instance
$fd = inotify_init();
// Watch __FILE__ for metadata changes (e.g. mtime)
$watch_descriptor = inotify_add_watch($fd, __FILE__, IN_ATTRIB);
// generate an event
touch(__FILE__);
// Read events
$events = inotify_read($fd);
print_r($events);
// The following methods allows to use inotify functions without blocking on inotify_read():
// - Using stream_select() on $fd:
$read = array($fd);
$write = null;
$except = null;
stream_select($read,$write,$except,0);
// - Using stream_set_blocking() on $fd
stream_set_blocking($fd, 0);
inotify_read($fd); // Does no block, and return false if no events are pending
// - Using inotify_queue_len() to check if event queue is not empty
$queue_len = inotify_queue_len($fd); // If > 0, inotify_read() will not block
// Stop watching __FILE__ for metadata changes
inotify_rm_watch($fd, $watch_descriptor);
// Close the inotify instance
// This may have closed all watches if this was not already done
fclose($fd);
?>`

The above example will output something similar to:

    array(
      array(
        'wd' => 1,     // Equals $watch_descriptor
        'mask' => 4,   // IN_ATTRIB bit is set
        'cookie' => 0, // unique id to connect related events (e.g.
                       // IN_MOVE_FROM and IN_MOVE_TO events)
        'name' => '',  // the name of a file (e.g. if we monitored changes
                       // in a directory)
      ),
    );

### See Also

- inotify_add_watch
- inotify_rm_watch
- inotify_queue_len
- inotify_read
- fclose