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. On Windows, when using -DUNICODE, the parameter type changes to wchar_t *.

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);

Tk_Main functions much the same as Tcl_Main. In particular, Tk_Main supports both an interactive mode and a startup script mode, with the file name and encoding of a startup script under the control of the Tcl_SetStartupScript and Tcl_GetStartupScript routines. However it calls Tk_MainLoop after processing any supplied script, and in interactive uses events registered with Tcl_CreateFileHandler to process user input.

SEE ALSO¶

Tcl_DoOneEvent(3tk)

KEYWORDS¶

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