pcap_get_selectable_fd(3pcap) on macOS
The text a6792b000e2c, as macOS 12.5, macOS 12.4, macOS 12.3, macOS 12.2, macOS 12.1, macOS 12.0.1, macOS 11.5, macOS 11.4, macOS 11.3, macOS 11.2, macOS 11.1, macOS 11.0.1, macOS 10.15.6, macOS 10.15.5, macOS 10.15.4, macOS 10.15.3, macOS 10.15.2 shipped it.
get a file descriptor on which a select() can be done for a live capture