XmToggleButtonGetState(3) on Linux
The text ada713daeda1, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A ToggleButton function that obtains the state of a ToggleButton "XmToggleButtonGetState" "ToggleButton functions" "XmToggleButtonGetState"