# libtmux::NotificationWatch::notification_fd

- **Module:** libtmux::NotificationWatch
- **Package:** libtmux-cxx
- **Language:** C++
- **Kind:** method
- **Source:** https://github.com/libtmux/libtmux-cxx/blob/85e8bd603a322dc32bb8b9aeb1a72bcf36945f1d/include/libtmux/notification.hpp#L121
- **Page:** https://libtmux.org/reference/cxx/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.