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XOpenDisplay(3) 		 XLIB FUNCTIONS 		 XOpenDisplay(3)

NAME
     XOpenDisplay, XCloseDisplay - connect or disconnect to X server

SYNTAX
     Display *XOpenDisplay(_Xconst 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 sys-
	       tem, 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 sin-
     gle colon (:) separates the hostname and display number, XOpenDisplay  con-
     nects using TCP streams.  If the hostname is not specified, Xlib uses what-
     ever  it  believes is the fastest transport.  If the hostname is a host ma-
     chine name and a double colon (::) separates the hostname and display  num-
     ber, XOpenDisplay connects using DECnet.  A single X server can support any
     or all of these transport mechanisms simultaneously.  A particular Xlib im-
     plementation 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 dis-
     play_name argument is returned by the DefaultScreen macro (or the XDefault-
     Screen function).	You can access elements of the Display and Screen struc-
     tures  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,  re-
     source 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).  There-
     fore, these windows, resource IDs, and other resources should never be ref-
     erenced 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 1.8.13 		 XOpenDisplay(3)

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