Naming windows and defining icons

XStoreName(display,w, name) /* assign a name to a window */
    char *name;          /* name: a null-terminated string      */

Status XFetchName(display,w, name) /* find a window's name */
    char **name;         /* RETURN a pointer to the name array  */

XSetIconName(display,w,icon_name) /* set name used on icon */
    icon_name *char;

Status XGetIconName(display,w,icon_name) /* get name used on icon */
    icon_name **char;   /*RETURN*/

To set groups of properties there are 2 structures:-

typedef struct{
long flags; /*InputHint,StateHint,IconPixmapHint,IconWindowHint,
            IconPositionHint,IconMaskHint, WindowGroupHint, AllHints */
Bool input;           /* does this application rely on the window manager
                         to get keyboard input ? */
int initial_state; /*NormalState,ZoomState,IconicState,InactiveState,DontCareState*/
Pixmap icon_pixmap;
Window icon_window;   /* window to be used as icon */
int icon_x, icon_y;   /*initial icon position*/
Pixmap icon_mask;
XID window_group;     /* windows can be grouped so that, for example,
                         they could all be de-iconified at once */
} XWMHints;

typedef struct {
  long flags;    /* which fields are defined. Possibilities are
                 USPosition, USSize, PPosition, Psize, PMinSize
                 PMaxSize, PResizeInc, PAspect, PAllHints */
  int x,y;
  int width, height;
  int min_width, max_width;
  int min_height, max_height;
  int width_inc, height_inc;
  struct {
         int x; /* numerator   */
         int y; /* demoninator */
  } min_aspect, max_aspect;
} XSizeHints;

Control over the step size of the increment is useful if, say, you want to allow change of a text window by units of a character cell.

These structures are used in these routines:-

void XSetNormalHints(display, w, hints)
     Display *display;
     Window  w;
     XSizeHints *hints;

void XGetNormalHints(display, w, hints)
     Display *display;
     Window  w;
     XSizeHints *hints;  /* RETURNED*/

XSetStandardProperties(display,w,window_name,icon_name,
                icon_pixmap,argv,argc,hints)
char *window_name, *icon_name;
Pixmap icon_pixmap;
char **argv;             /* the command line to start the application*/   
int  argc;               
XSizeHints *hints;

XSetWMHints(display,w,wmhints)
XWMHints *wmhints;

XWMHints *XGetWMHints(display,w,wmhints)
XWMHints *wmhints;

If you set maximum size, minimum size and original size to be all the same, and the window manager takes your hints, then your window will be of fixed size.