XmStringPeekNextComponent(3) on Linux
The text 89a8ccbad88b, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A compound string function that returns the component type of the next component to be fetched "XmStringPeekNextComponent" "compound string functions" "XmStringPeekNextComponent"