XmTextFieldGetSelection(3) on Linux
The text d0ac93853b75, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A TextField function that retrieves the value of the primary selection "XmTextFieldGetSelection" "TextField functions" "XmTextFieldGetSelection"