XtDisplayInitialize(3Xt)

     NAME
          XtDisplayInitialize, XtOpenDisplay, XtDatabase,
          XtScreenDatabase, XtCloseDisplay - initialize, open, or
          close a display

     SYNTAX
          void XtDisplayInitialize(app_context, display,
          application_name, application_class,
                                 options, num_options, argc, argv)
                XtAppContext app_context;
                Display *display;
                String application_name;
                String application_class;
                XrmOptionDescRec *options;
                Cardinal num_options;
                int *argc;
                String *argv;

          Display *XtOpenDisplay(app_context, display_string,
          application_name, application_class,
                                 options, num_options, argc, argv)
                 XtAppContext app_context;
                 String display_string;
                 String application_name;
                 String application_class;
                 XrmOptionDescRec *options;
                 Cardinal num_options;
                 int *argc;
                 String *argv;

          void XtCloseDisplay(display)
                Display *display;

          XrmDatabase XtDatabase(display)
                Display *display;

          XrmDatabase XtScreenDatabase(screen)
                Screen* screen;

     ARGUMENTS
          argc      Specifies a pointer to the number of command line
                    parameters.

          argv      Specifies the command line parameters.

          app_context
                    Specifies the application context.

          application_class
                    Specifies the class name of this application,
                    which usually is the generic name for all
                    instances of this application.
          application_name
                    Specifies the name of the application instance.

          display   Specifies the display.  Note that a display can be
                    in at most one application context.

          num_options
                    Specifies the number of entries in the options
                    list.

          options   Specifies how to parse the command line for any
                    application-specific resources.  The options
                    argument is passed as a parameter to
                    XrmParseCommand.  For further information, see
                    Xlib - C Language X Interface.

          screen    Specifies the screen whose resource database is to
                    be returned.

     DESCRIPTION
          The XtDisplayInitialize function builds the resource
          database, calls the Xlib XrmParseCommand function to parse
          the command line, and performs other per display
          initialization.  After XrmParseCommand has been called, argc
          and argv contain only those parameters that were not in the
          standard option table or in the table specified by the
          options argument.  If the modified argc is not zero, most
          applications simply print out the modified argv along with a
          message listing the allowable options.  On UNIX-based
          systems, the application name is usually the final component
          of argv[0].  If the synchronize resource is True for the
          specified application, XtDisplayInitialize calls the Xlib
          XSynchronize function to put Xlib into synchronous mode for
          this display connection.  If the reverseVideo resource is
          True, the Intrinsics exchange XtDefaultForeground and
          XtDefaultBackground for widgets created on this display.
          (See Section 9.6.1).

          The XtOpenDisplay function calls XOpenDisplay the specified
          display name.  If display_string is NULL, XtOpenDisplay uses
          the current value of the -display option specified in argv
          and if no display is specified in argv, uses the user's
          default display (on UNIX-based systems, this is the value of
          the DISPLAY environment variable).

          If this succeeds, it then calls XtDisplayInitialize and pass
          it the opened display and the value of the -name option
          specified in argv as the application name.  If no name
          option is specified, it uses the application name passed to
          XtOpenDisplay.  If the application name is NULL, it uses the
          last component of argv[0].  XtOpenDisplay returns the newly
          opened display or NULL if it failed.
          XtOpenDisplay is provided as a convenience to the
          application programmer.

          The XtCloseDisplay function closes the specified display as
          soon as it is safe to do so.  If called from within an event
          dispatch (for example, a callback procedure), XtCloseDisplay
          does not close the display until the dispatch is complete.
          Note that applications need only call XtCloseDisplay if they
          are to continue executing after closing the display;
          otherwise, they should call XtDestroyApplicationContext or
          just exit.

          The XtDatabase function returns the fully merged resource
          database that was built by XtDisplayInitialize associated
          with the display that was passed in.  If this display has
          not been initialized by XtDisplayInitialize, the results are
          not defined.

          The XtScreenDatabase function returns the fully merged
          resource database associated with the specified screen. If
          the screen does not belong to a Display initilized by
          XtDisplayInitialize, the results are undefined.

     SEE ALSO
          XtAppCreateShell(3Xt), XtCreateApplicationContext(3Xt)
          X Toolkit Intrinsics - C Language Interface
          Xlib - C Language X Interface