main program for Tcl-based applications 

Tcl Library Procedures


#include <tcl.h>

Tcl_Main(argc, argv, appInitProc)


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().


Tcl_Main() acts as the main program for most Tcl-based applications. Starting with Tcl 7.4 it is not called main anymore because it is part of the Tcl library and having a function main in a library (particularly a shared library) causes problems on many systems. Having main in the Tcl library would also make it hard to use Tcl 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 Tcl_Main(). Tcl_Main() then does all the work of creating and running a tclsh-like application.

When it is has finished its own initialization, but before it processes commands, Tcl_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().


Windows Server 2012. Windows 8.1. Windows Server 2012 R2. Windows 10. Windows Server 2016. Windows Server 2019.


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