Th_Interp *th1Interp = (Th_Interp *)clientData;
  if( !th1Interp ) return;
  /* Remove the Tcl integration commands. */
  for(i=0; i<(sizeof(aCommand)/sizeof(aCommand[0])); i++){
    Th_RenameCommand(th1Interp, aCommand[i].zName, -1, NULL, 0);
  }
}

/*
** Sets the "argv0", "argc", and "argv" script variables in the Tcl interpreter
** based on the supplied command line arguments.
 */
static int setTclArguments(
  Tcl_Interp *pInterp,
  int argc,
  char **argv
){
  Tcl_Obj *objPtr;
  Tcl_Obj *resultObjPtr;
  Tcl_Obj *listPtr;
  int rc;
  if( argc<=0 || !argv ){
    return TCL_OK;
  }
  objPtr = Tcl_NewStringObj(argv[0], -1);
  Tcl_IncrRefCount(objPtr);
  resultObjPtr = Tcl_SetVar2Ex(pInterp, "argv0", NULL, objPtr,
      TCL_GLOBAL_ONLY|TCL_LEAVE_ERR_MSG);
  Tcl_DecrRefCount(objPtr);
  if( !resultObjPtr ){
    return TCL_ERROR;
  }
  objPtr = Tcl_NewIntObj(argc - 1);
  Tcl_IncrRefCount(objPtr);
  resultObjPtr = Tcl_SetVar2Ex(pInterp, "argc", NULL, objPtr,
      TCL_GLOBAL_ONLY|TCL_LEAVE_ERR_MSG);
  Tcl_DecrRefCount(objPtr);
  if( !resultObjPtr ){
    return TCL_ERROR;
  }
  if( argc>1 ){
    listPtr = Tcl_NewListObj(0, NULL);
    Tcl_IncrRefCount(listPtr);
    while( --argc ){
      objPtr = Tcl_NewStringObj(*++argv, -1);
      Tcl_IncrRefCount(objPtr);
      rc = Tcl_ListObjAppendElement(pInterp, listPtr, objPtr);
      Tcl_DecrRefCount(objPtr);
      if( rc!=TCL_OK ){
        break;
      }
    }
    if( rc==TCL_OK ){
      resultObjPtr = Tcl_SetVar2Ex(pInterp, "argv", NULL, listPtr,
          TCL_GLOBAL_ONLY|TCL_LEAVE_ERR_MSG);
      if( !resultObjPtr ){
        rc = TCL_ERROR;
      }
    }
    Tcl_DecrRefCount(listPtr);
  }
  return rc;
}

/*
** Creates and initializes a Tcl interpreter for use with the specified TH1
** interpreter.  Stores the created Tcl interpreter in the Tcl context supplied
** by the caller.
 */
static int createTclInterp(
  Th_Interp *interp,
  void *pContext
){
  struct TclContext *tclContext = (struct TclContext *)pContext;
  int argc;
  char **argv;
  Tcl_Interp *tclInterp;

  if ( !tclContext ){
    Th_ErrorMessage(interp,
        "Invalid Tcl context", (const char *)"", 0);
    return TH_ERROR;
  }
  if ( tclContext->interp ){
    return TH_OK;
  }
  argc = tclContext->argc;
  argv = tclContext->argv;
  if ( argc>0 && argv ) {
    Tcl_FindExecutable(argv[0]);
  }
  tclInterp = tclContext->interp = Tcl_CreateInterp();
  if( !tclInterp || Tcl_InterpDeleted(tclInterp) ){
    Th_ErrorMessage(interp,
        "Could not create Tcl interpreter", (const char *)"", 0);
    return TH_ERROR;
  }
  if( Tcl_Init(tclInterp)!=TCL_OK ){
    Th_ErrorMessage(interp,
        "Tcl initialization error:", Tcl_GetStringResult(tclInterp), -1);
    Tcl_DeleteInterp(tclInterp);
    tclContext->interp = tclInterp = 0;
    return TH_ERROR;
  }
  if( setTclArguments(tclInterp, argc, argv)!=TCL_OK ){
    Th_ErrorMessage(interp,
        "Tcl error setting arguments:", Tcl_GetStringResult(tclInterp), -1);
    Tcl_DeleteInterp(tclInterp);



    tclContext->interp = tclInterp = 0;
    return TH_ERROR;
  }

  /* Add the TH1 integration commands to Tcl. */
  Tcl_CallWhenDeleted(tclInterp, Th1DeleteProc, interp);
  Tcl_CreateObjCommand(tclInterp, "th1Eval", Th1EvalObjCmd, interp, NULL);
  Tcl_CreateObjCommand(tclInterp, "th1Expr", Th1ExprObjCmd, interp, NULL);
  return TH_OK;
}