Tcl_AppInit(3) Tcl Library Procedures Tcl_AppInit(3)
NAME
Tcl_AppInit - perform application-specific initialization
SYNOPSIS
#include <tcl.h>
int
Tcl_AppInit(interp)
ARGUMENTS
Interpreter for the application.
DESCRIPTION
Tcl_AppInit is a procedure that is invoked by the main programs for Tcl
applications such as tclsh and wish. Its purpose is to allow new Tcl
applications to be created without modifying the main programs provided
as part of Tcl and Tk. To create a new application you write a new
version of Tcl_AppInit to replace the default version provided by Tcl,
then link your new Tcl_AppInit with the Tcl library.
Tcl_AppInit is invoked by Tcl_Main and Tk_Main after their own initial-
ization and before entering the main loop to process commands. Here
are some examples of things that Tcl_AppInit might do:
[1] Call initialization procedures for various packages used by the
application. Each initialization procedure adds new commands to
interp for its package and performs other package-specific ini-
tialization.
[2] Process command-line arguments, which can be accessed from the
Tcl variables argv and argv0 in interp.
[3] Invoke a startup script to initialize the application.
Tcl_AppInit returns TCL_OK or TCL_ERROR. If it returns TCL_ERROR then
it must leave an error message in for the interpreter's result; other-
wise the result is ignored.
In addition to Tcl_AppInit, your application should also contain a pro-
cedure main that calls Tcl_Main as follows: Tcl_Main(argc, argv,
Tcl_AppInit); The third argument to Tcl_Main gives the address of the
application-specific initialization procedure to invoke. This means
that you do not have to use the name Tcl_AppInit for the procedure, but
in practice the name is nearly always Tcl_AppInit (in versions before
Tcl 7.4 the name Tcl_AppInit was implicit; there was no way to specify
the procedure explicitly). The best way to get started is to make a
copy of the file tclAppInit.c from the Tcl library or source directory.
It already contains a main procedure and a template for Tcl_AppInit
that you can modify for your application.
KEYWORDS
application, argument, command, initialization, interpreter
Tcl 7.0 Tcl_AppInit(3)
AppInit 8.5.4 - Generated Sun Aug 17 15:02:44 CDT 2008