XOpenDisplay(3X11)            X11 SDE 5.4R3.00            XOpenDisplay(3X11)


NAME
       XOpenDisplay, XCloseDisplay - connect or disconnect to X server

SYNTAX
       Display *XOpenDisplay(display_name)
             char *display_name;

       XCloseDisplay(display)
             Display *display;

ARGUMENTS
       display   Specifies the connection to the X server.

       display_name
                 Specifies the hardware display name, which determines the
                 display and communications domain to be used.  On a POSIX-
                 conformant 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 X server and that contains all the information
       about that X server.  XOpenDisplay connects your application to the X
       server through TCP or DECnet communications protocols, or through
       some local inter-process communication protocol.  If the hostname is
       a host machine name and a single colon (:) separates the hostname and
       display number, XOpenDisplay connects using TCP 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 single X 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 XOpenDisplay does not succeed,
       it returns NULL.  After a successful 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
       elements 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.

       The XCloseDisplay function closes the connection to the X server for
       the display specified in the Display structure and destroys all
       windows, resource IDs (Window, Font, Pixmap, 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



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XOpenDisplay(3X11)            X11 SDE 5.4R3.00            XOpenDisplay(3X11)


       so that any pending errors are reported as XCloseDisplay performs a
       final XSync operation.

       XCloseDisplay can generate a BadGC error.

SEE ALSO
       AllPlanes(3X11), XFlush(3X11), XSetCloseDownMode(3X11)
       Xlib - C Language X Interface

















































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