XOpenDisplay

XOpenDisplay(3X11)		XLIB FUNCTIONS		   XOpenDisplay(3X11)



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 trans-
       port.  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 sup-
       port 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 Default-
       Screen macro (or the XDefaultScreen function).  You can access ele-
       ments of the Display and Screen structures only by using the informa-
       tion macros or functions.  For information about using macros and
       functions to obtain information from the Display structure, see sec-
       tion 2.2.1.

       The XCloseDisplay function closes the connection to the X server for
       the display specified in the Display structure and destroys all win-
       dows, resource IDs (Window, Font, Pixmap, Colormap, Cursor, and GCon-
       text), or other resources that the client has created on this display,
       unless the close-down mode of the resource has been changed (see XSet-
       CloseDownMode).	Therefore, these windows, resource IDs, and other
       resources should never be referenced again or an error will be gener-
       ated.  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(3X11), XFlush(3X11), XSetCloseDownMode(3X11)
       Xlib - C Language X Interface



							   XOpenDisplay(3X11)