XtOpenApplication, XtVaOpenApplication - initialize, open, or close a display
#include <X11/Intrinsic.h>
Widget XtOpenApplication(XtAppContext
    *app_context_return, const char *application_class,
    XrmOptionDescRec *options, Cardinal num_options, int
    *argc_in_out, char **argv_in_out, String
    *fallback_resources, WidgetClass widget_class, ArgList
    args, Cardinal num_args);
Widget XtVaOpenApplication(XtAppContext
    *app_context_return, const char *application_class,
    XrmOptionDescRec *options, Cardinal num_options, int
    *argc_in_out, char **argv_in_out, String
    *fallback_resources, WidgetClass widget_class, ...);
  - app_context_return
- 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.
- 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.
- num_options
- Specifies the number of entries in the options list.
- argc_in_out
- Specifies a pointer to the number of command line parameters.
- argv_in_out
- Specifies the command line parameters.
- fallback_resources
- Specifies resource values to be used if the application class resource
      file cannot be opened or read, or NULL.
- widget_class
- Specifies the widget class of the shell to be created.
- args
- Specifies the argument list to override any other resource specification
      for the created shell widget.
- num_args
- Specifies the number of entries in the argument list.
- ...
- Specifies the variable argument list to override any other resource
      specification for the created shell widget.
The XtOpenApplication function calls XtToolkitInitialize followed
  by XtCreateApplicationContext, then calls XtOpenDisplay with
  display_string NULL and application_name NULL, and finally calls
  XtAppCreateShell with application_name NULL, the specified
  widget_class, and the specified args and num_args and
  returns the created shell. The modified argc and argv returned
  by XtDisplayInitialize are returned in argc_in_out and
  argv_in_out. If app_context_return is not NULL, the created
  application context is also returned. If the display specified by the command
  line cannot be opened, an error message is issued and XtOpenApplication
  terminates the application. If fallback_resources is non-NULL,
  XtAppSetFallbackResources is called with the value prior to calling
  XtOpenDisplay.XtAppInitialize and XtVaAppInitialize have been superceded by
    XtOpenApplication and XtVaOpenApplication respectively.
XtAppInitialize(3), XtVaAppInitialize(3)
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface