https://invisible-island.net/xterm/xtoolkit/
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 *fall-
back_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 *fall-
back_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 dis-
play_string NULL and application_name NULL, and finally calls XtAppCre-
ateShell 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 XtOpen-
Application and XtVaOpenApplication respectively.
XtAppInitialize(3), XtVaAppInitialize(3)
X Toolkit Intrinsics – C Language Interface
Xlib - C Language X Interface
X Version 11 libXt 1.1.5.2 XtOpenApplication(3)