# libtmux::NotificationWatch::notification_fd

- **Module:** libtmux::NotificationWatch
- **Package:** libtmux-cxx
- **Language:** C++
- **Kind:** method
- **Source:** https://github.com/libtmux/libtmux-cxx/blob/393d4b0ad666f18a6581f1eb281741a75a7503f0/include/libtmux/notification.hpp#L144
- **Page:** https://libtmux.org/en/cxx/latest/reference/libtmux-notificationwatch-notification_fd/

```
libtmux::NotificationWatch::notification_fd() -> int
```

Readable when this watch has something to take or its stream has closed.

Do not read it; taking all available events clears this watch's byte while the stream is open, and closure remains readable. `-1` means the pipe could not be created or the watch is empty/moved from.