The following questions tend to be asked regularly on the comp.lang.tcl newsgroup:
   * ''I have a large [C]/[C++] program, how do I make it scriptable with [Tcl]?''
   * ''I have a large C/C++ program, how do I add a [Tk] [GUI] to it?''

At a high level, there are three different solutions to consider.

  1.  Embed Tcl calls in my C/C++ code.

  2.  Wrap my C/C++ code to make it callable from Tcl.
      Replace the C/C++ main() with a tclsh/wish main program

  3.  Something else

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'''Embed Tcl Calls in C/C++ code'''

While the text
"[Why adding Tcl calls to a C/C++ application is a bad idea]"
is an interesting dialog concerning the appropriate
approach to performing this task,
where can one find specific coding examples and documentation
regarding what one needs to do, in a C program, if one needs to create
an interpreter and then execute tcl commands making use of that interpreter.

Well, one example comes ''out of the box'' with both Tcl and Tk.
Take a look at the tcl/unix/tclAppInit.c (or tcl/win/tclAppInit.c) files
in the tcl source distribution (which is the mainline C module for the
tclsh command), and in the Tk source distribution, tk/unix/tkAppInit.c 
or tk/win/winMain.c (I don't understand why the name difference here...).
For MacOS, see tk/mac/tkMacAppInit.c and tk/macosx/tkMacOSXAppInit.c
(again, I don't understand the reasoning for file name changes).
These provide at least a basic skeleton for initializing an interpreter.
Unfortunately, they leave you in an interpretive mode which most people
don't want to happen.  So another example is needed.

I do know there are two kinds of Tcl actions one can invoke from C/C++
Since Tcl is ''just'' a C library, some Tcl actions can be invoked by calling
the appropriate Tcl function call.

However, some things in Tcl must be done by invoking [Tcl_Eval], after 
appropriately setting up a Tcl interpreter.

Can someone provide some sample C or C++ code that shows setting up the
interpreter, then perhaps invoking things each way?

A dream scenario would do this for Tcl/Tk since that is a superset of
the same kind of request for Tcl... 

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