/* 

 * tclHistory.c --

 *

 *	This module and the Tcl library file history.tcl together implement

 *	Tcl command history. Tcl_RecordAndEval(Obj) can be called to record

 *	commands ("events") before they are executed. Commands defined in

 *	history.tcl may be used to perform history substitutions.

 *

 * Copyright (c) 1990-1993 The Regents of the University of California.

 * Copyright (c) 1994-1997 Sun Microsystems, Inc.

 * Portions Copyright (c) 2007-2008 Nokia Corporation and/or its subsidiaries. All rights reserved.  

 *

 * See the file "license.terms" for information on usage and redistribution

 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.

 *

 * RCS: @(#) $Id: tclHistory.c,v 1.4 2002/01/16 06:02:34 dgp Exp $

 */

#include "tclInt.h"

#include "tclPort.h"

/*

 *----------------------------------------------------------------------

 *

 * Tcl_RecordAndEval --

 *

 *	This procedure adds its command argument to the current list of

 *	recorded events and then executes the command by calling

 *	Tcl_Eval.

 *

 * Results:

 *	The return value is a standard Tcl return value, the result of

 *	executing cmd.

 *

 * Side effects:

 *	The command is recorded and executed.

 *

 *----------------------------------------------------------------------

 */

EXPORT_C int

Tcl_RecordAndEval(interp, cmd, flags)

    Tcl_Interp *interp;		/* Token for interpreter in which command

				 * will be executed. */

    CONST char *cmd;		/* Command to record. */

    int flags;			/* Additional flags.  TCL_NO_EVAL means

				 * only record: don't execute command.

				 * TCL_EVAL_GLOBAL means use Tcl_GlobalEval

				 * instead of Tcl_Eval. */

{

    register Tcl_Obj *cmdPtr;

    int length = strlen(cmd);

    int result;

    if (length > 0) {

	/*

	 * Call Tcl_RecordAndEvalObj to do the actual work.

	 */

	cmdPtr = Tcl_NewStringObj(cmd, length);

	Tcl_IncrRefCount(cmdPtr);

	result = Tcl_RecordAndEvalObj(interp, cmdPtr, flags);

	/*

	 * Move the interpreter's object result to the string result, 

	 * then reset the object result.

	 */

	Tcl_SetResult(interp, TclGetString(Tcl_GetObjResult(interp)),

	        TCL_VOLATILE);

	/*

	 * Discard the Tcl object created to hold the command.

	 */

	Tcl_DecrRefCount(cmdPtr);	

    } else {

	/*

	 * An empty string. Just reset the interpreter's result.

	 */

	Tcl_ResetResult(interp);

	result = TCL_OK;

    }

    return result;

}

/*

 *----------------------------------------------------------------------

 *

 * Tcl_RecordAndEvalObj --

 *

 *	This procedure adds the command held in its argument object to the

 *	current list of recorded events and then executes the command by

 *	calling Tcl_EvalObj.

 *

 * Results:

 *	The return value is a standard Tcl return value, the result of

 *	executing the command.

 *

 * Side effects:

 *	The command is recorded and executed.

 *

 *----------------------------------------------------------------------

 */

EXPORT_C int

Tcl_RecordAndEvalObj(interp, cmdPtr, flags)

    Tcl_Interp *interp;		/* Token for interpreter in which command

				 * will be executed. */

    Tcl_Obj *cmdPtr;		/* Points to object holding the command to

				 * record and execute. */

    int flags;			/* Additional flags. TCL_NO_EVAL means

				 * record only: don't execute the command.

				 * TCL_EVAL_GLOBAL means evaluate the

				 * script in global variable context instead

				 * of the current procedure. */

{

    int result;

    Tcl_Obj *list[3];

    register Tcl_Obj *objPtr;

    /*

     * Do recording by eval'ing a tcl history command: history add $cmd.

     */

    list[0] = Tcl_NewStringObj("history", -1);

    list[1] = Tcl_NewStringObj("add", -1);

    list[2] = cmdPtr;

    objPtr = Tcl_NewListObj(3, list);

    Tcl_IncrRefCount(objPtr);

    (void) Tcl_EvalObjEx(interp, objPtr, TCL_EVAL_GLOBAL);

    Tcl_DecrRefCount(objPtr);

    /*

     * Execute the command.

     */

    result = TCL_OK;

    if (!(flags & TCL_NO_EVAL)) {

	result = Tcl_EvalObjEx(interp, cmdPtr, flags & TCL_EVAL_GLOBAL);

    }

    return result;

}