XOpenDisplay

XOpenDisplay(3)                 XLIB FUNCTIONS                 XOpenDisplay(3)



NAME
       XOpenDisplay, XCloseDisplay - connect or disconnect to X server

SYNTAX
       Display *XOpenDisplay(char *display_name);

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

       XCloseDisplay can generate a BadGC error.

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



X Version 11                     libX11 1.6.9                  XOpenDisplay(3)