Tk_Main(argc, argv, appInitProc)
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.