XmMultiListGetSelectedRows man page
XmMultiListGetSelectedRows — an MultiList function that returns the rows that currently are selected.
#include <Xm/MultiList.h> XmMultiListRowInfo ** XmMultiListGetSelectedRows( Widget widget);
Use this routine to find the rows that currently are selected in an MultiList widget.
Specifies the ID of the MultiList widget.
For a complete definition of MultiList and its associated resources, see XmMultiList(3).
The XmMultiListRowInfo ** returned by this function contains a NULL terminated array of XmMultiListRowInfo pointers. The calling routine is responsible for freeing the returned pointer with XtFree(). The function will return NULL if no elements are selected.