XmTextGetSelection — A Text function that retrieves the value of the primary selection

XmTextGetSelection retrieves the value of the primary selection. It returns a NULL pointer if no text  is
       selected in the widget. The application is responsible for freeing the storage associated with the string
       by calling XtFree.

       widget    Specifies the Text widget ID

       For a complete definition of Text and its associated resources, see XmText(3).

XmTextGetSelection   —   A   Text   function   that   retrieves   the  value  of  the  primary  selection
       "XmTextGetSelection" "Text functions" "XmTextGetSelection"

XmText(3) and XmTextGetSelectionWcs(3).

                                                                                           XmTextGetSelection(3)

       Returns a character pointer to the string that is associated with the primary selection.

       #include <Xm/Text.h>
       char*XmTextGetSelection(
       Widgetwidget);