XOpenDisplay(3X11)                             XOpenDisplay(3X11)



NAME
     XOpenDisplay, XCloseDisplay - connect or disconnect to XWIN
     server

SYNTAX
     Display *XOpenDisplay(display_name)
           char *display_name;

     XCloseDisplay(display)
           Display *display;

ARGUMENTS
     display   Specifies the connection to the XWIN server.

     display_name
               Specifies the hardware display name, which deter-
               mines the display and communications domain to be
               used.  On a UNIX-based system, if the display_name
               is NULL, it defaults to the value of the DISPLAY
               environment variable.

DESCRIPTION
     The XOpenDisplay function returns a Display structure that
     serves as the connection to the XWIN server and that con-
     tains all the information about that XWIN server.  XOpen-
     Display connects your application to the XWIN server through
     TCP, UNIX domain, or DECnet communications protocols.  If
     the hostname is a host machine name and a single colon (:)
     separates the hostname and display number, XOpenDisplay con-
     nects using TCP streams.  If the hostname is unix and a sin-
     gle colon (:) separates it from the display number, XOpen-
     Display connects using UNIX domain IPC streams.  If the
     hostname is not specified, Xlib uses whatever it believes is
     the fastest transport.  If the hostname is a host machine
     name and a double colon (::)  separates the hostname and
     display number, XOpenDisplay connects using DECnet.  A sin-
     gle XWIN server can support any or all of these transport
     mechanisms simultaneously.  A particular Xlib implementation
     can support many more of these transport mechanisms.

     If successful, XOpenDisplay returns a pointer to a Display
     structure, which is defined in <X11/Xlib.h>.  If XOpen-
     Display does not succeed, it returns NULL.  After a success-
     ful call to XOpenDisplay, all of the screens in the display
     can be used by the client.  The screen number specified in
     the display_name argument is returned by the DefaultScreen
     macro (or the XDefaultScreen function).  You can access ele-
     ments of the Display and Screen structures only by using the
     information macros or functions.  For information about
     using macros and functions to obtain information from the
     Display structure, see section 2.2.1, Xlib-C Language X
     Interface.



XWIN 3.0               Last change: 9/1/88                 .ie t

XOpenDisplay(3X11)                             XOpenDisplay(3X11)



     The XCloseDisplay function closes the connection to the XWIN
     server for the display specified in the Display structure
     and destroys all windows, resource IDs (Window, Font, Pix-
     map, Colormap, Cursor, and GContext), or other resources
     that the client has created on this display, unless the
     close-down mode of the resource has been changed (see
     XSetCloseDownMode).  Therefore, these windows, resource IDs,
     and other resources should never be referenced again or an
     error will be generated.  Before exiting, you should call
     XCloseDisplay explicitly so that any pending errors are
     reported as XCloseDisplay performs a final XSync operation.

     XCloseDisplay can generate a BadGC error.

SEE ALSO
     Xlib - C Language X Interface







































XWIN 3.0               Last change: 9/1/88                 .ie t

XOpenDisplay(3X11)                             XOpenDisplay(3X11)























































XWIN 3.0               Last change: 9/1/88                 .ie t