main program for Tk-based applications

## NAME

Tk_Main - main program for Tk-based applications

## SYNOPSIS

#include <tk.h>

Tk_Main(argc, argv, appInitProc)

## ARGUMENTS

`int argc` (in)
  Number of elements in argv.
`char *argv[]` (in)
  Array of strings containing command-line arguments.
`Tcl_AppInitProc *appInitProc` (in)
  Address of an application-specific initialization procedure. The value for this argument is usually Tcl_AppInit.

## DESCRIPTION

Tk_Main acts as the main program for most Tk-based applications. Starting with Tk 4.0 it is not called main anymore because it is part of the Tk library and having a function main in a library (particularly a shared library) causes problems on many systems. Having main in the Tk library would also make it hard to use Tk in C++ programs, since C++ programs must have special C++ main functions.

Normally each application contains a small main function that does nothing but invoke Tk_Main. Tk_Main then does all the work of creating and running a wish-like application.

When it is has finished its own initialization, but before it processes commands, Tk_Main calls the procedure given by the appInitProc argument. This procedure provides a ``hook'' for the application to perform its own initialization, such as defining application-specific commands. The procedure must have an interface that matches the type Tcl_AppInitProc:
typedef int Tcl_AppInitProc(Tcl_Interp *interp);
AppInitProc is almost always a pointer to Tcl_AppInit; for more details on this procedure, see the documentation for Tcl_AppInit.

## KEYWORDS

application-specific initialization, command-line arguments, main program