XmTextFieldSetSelection(3) on Linux
The text eb87f63fc9c4, 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 sets the primary selection of the text "XmTextFieldSetSelection" "TextField functions" "XmTextFieldSetSelection"