GNU/Linux |
RedHat 9.0(Shrike) |
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Tcl_Main(3) |
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Tcl_Main, Tcl_SetMainLoop − main program and event loop definition for Tcl-based applications
#include <tcl.h>
Tcl_Main(argc, argv, appInitProc)
Tcl_SetMainLoop(mainLoopProc)
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_MainLoopProc *mainLoopProc (in) |
Address of an application-specific event loop procedure. |
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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. When the appInitProc is finished, the startup script will be evaluated. If none exists, then an interactive prompt is provided.
Tcl_SetMainLoop allows setting an event loop procedure to be run. This │ allows, for example, Tk to be dynamically loaded and set its event │ loop. The event loop will run following the startup script. If you │ are in interactive mode, setting the main loop procedure will cause the │ prompt to become fileevent based and then the loop procedure is called. │ The main loop procedure must have an interface that matches the type │ Tcl_MainLoopProc: │
typedef void Tcl_MainLoopProc(void); │
application-specific initialization, command-line arguments, main program
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Tcl_Main(3) | ![]() |