Problems installing and using inotify

[adefaria]

I'm having issues using inotify on Ubuntu 24.04 with PHP 8.3.6.

Initially, I was calling inotify_read_events but it was complaining that that was not found. I found out that inotify_read was there and that appeared to work... at least from the CLI of PHP. But when I call it from a web page, I get:

function_exists('inotify_read_events') returns FALSE.

And if I change the webpage to call inotify_read I get:

PHP Fatal error:  Uncaught Error: Undefined constant "IN_NONBLOCK"

I'm pretty sure that both cli and apache2 have been configured correctly.