Running A Window Manager

As already mentioned, a window manager in X is a client application, but by convention, has special duties which, among others, includes control of the layout of the windows on the screen. A window manager called twm is provided with version 11 release 5 of the X window software distributed by the X Consortium. However, there are many others freely available, which can be used instead of twm. Given the situation in figure 10, a window manager can either run on the local computer sun or the remote computer hp. In either case, it may connect to the server on sun and manage the windows on its screen. Typing the command twm & in the upper left xterm window, or the command twm -display sun:0.0 & in the lower right one, but not both, will start the twm window manager. The screen should then look like that shown in figure 11.

 
Figure 11: Running the twm window manager

Twm has added a title bar to both xterm windows. In fact, most window managers add a title bar to each client's main window. The title bar added by twm contains a small button on the left, a title in slanting typeface and a small button on the right. Clicking the left mouse button with the mouse pointer in the title bar's left button turns the window into an icon. Holding down the left mouse button with the mouse pointer in the title bar's right button and dragging the mouse, allows the user to resize the window. The area in between these two title bar buttons also serves a purpose. Clicking the left mouse button with the mouse pointer in this area alters the windows stacking order. Holding down the middle mouse button produces a menu of commands which operate on the window. Holding down the right mouse button and dragging the mouse provides another means of resizing the window. Furthermore, operating the mouse buttons with the mouse pointer on the root window (ie. not in any application window) invokes a set of menus associated with the X session as a whole, rather than to any particular window. The contents of a file called .twmrc in the user's home directory can be used to customize twm.