XmMultiListGetSelectedRowArray man page
XmMultiListGetSelectedRowArray — an MultiList function that returns an array of integers which are selected row numbers.
#include <Xm/MultiList.h> int * XmMultiListGetSelectedRowArray( Widget widget, int * num_rows);
This routine creates an array of integers which are selected row numbers in the MultiList widget.
Specifies the ID of the MultiList widget.
Specifies pointer to the integer indicates number of returned row numbers.
For a complete definition of MultiList and its associated resources, see XmMultiList(3).
The int * returned by this function contains a selected rows numbers array. The calling routine is responsible for freeing the returned pointer with XtFree(). The function will return NULL if no elements are selected.