Tk_SetClass, Tk_Class - set or retrieve a window's class

       Tk_Window tkwin (in)           Token for window.

       char *class (in)               New class name for window.
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Tk_SetClass  is  called  to  associate a class with a particular window.  The class string identifies the
       type of the window;  all windows with the same general class of behavior (button, menu, etc.) should have
       the same class.  By convention all class names start with a  capital  letter,  and  there  exists  a  Tcl
       command  with  the  same  name  as  each class (except all in lower-case) which can be used to create and
       manipulate windows of that class.  A window's class string is initialized to  NULL  when  the  window  is
       created.

       For  main windows, Tk automatically propagates the name and class to the WM_CLASS property used by window
       managers.  This happens either when a main window is actually created (e.g.  in  Tk_MakeWindowExist),  or
       when  Tk_SetClass is called, whichever occurs later.  If a main window has not been assigned a class then
       Tk will not set the WM_CLASS property for the window.

       Tk_Class is a macro that returns the current value of tkwin's class.  The value is returned as a  Tk_Uid,
       which  may be used just like a string pointer but also has the properties of a unique identifier (see the
       manual entry for Tk_GetUid for details).  If tkwin has not yet been given a  class,  then  Tk_Class  will
       return NULL.

       class, unique identifier, window, window manager

Tk                                                                                              Tk_SetClass(3tk)

       Tk_SetClass, Tk_Class - set or retrieve a window's class

#include<tk.h>Tk_SetClass(tkwin,class)

       Tk_Uid
       Tk_Class(tkwin)