new file mode 100644
--- /dev/null
+++ b/src/if_tcl.c
@@ -0,0 +1,2118 @@
+/* vi:set ts=8 sw=4:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+
+/*
+ * Tcl extensions by Ingo Wilken <Ingo.Wilken@informatik.uni-oldenburg.de>
+ * Last modification: Wed May 10 21:28:44 CEST 2000
+ * Requires Tcl 8.0 or higher.
+ *
+ *  Variables:
+ *  ::vim::current(buffer)	# Name of buffer command for current buffer.
+ *  ::vim::current(window)	# Name of window command for current window.
+ *  ::vim::range(start)		# Start of current range (line number).
+ *  ::vim::range(end)		# End of current range (line number).
+ *  ::vim::lbase		# Start of line/column numbers (1 or 0).
+ *
+ *  Commands:
+ *  ::vim::command {cmd}	# Execute ex command {cmd}.
+ *  ::vim::option {opt} [val]	# Get/Set option {opt}.
+ *  ::vim::expr {expr}		# Evaluate {expr} using vim's evaluator.
+ *  ::vim::beep			# Guess.
+ *
+ *  set buf [::vim::buffer {n}]	# Create Tcl command for buffer N.
+ *  set bl [::vim::buffer list] # Get list of Tcl commands of all buffers.
+ *  ::vim::buffer exists {n}	# True if buffer {n} exists.
+ *
+ *  set wl [::vim::window list] # Get list of Tcl commands of all windows.
+ *
+ *  set n [$win height]		# Report window height.
+ *  $win height {n}		# Set window height to {n}.
+ *  array set pos [$win cursor] # Get cursor position.
+ *  $win cursor {row} {col}	# Set cursor position.
+ *  $win cursor pos		# Set cursor position from array var "pos"
+ *  $win delcmd {cmd}		# Register callback command for closed window.
+ *  $win option {opt} [val]	# Get/Set vim option in context of $win.
+ *  $win command {cmd}		# Execute ex command in context of $win.
+ *  $win expr {expr}		# Evaluate vim expression in context of $win.
+ *  set buf [$win buffer]	# Create Tcl command for window's buffer.
+ *
+ *  $buf name			# Reports file name in buffer.
+ *  $buf number			# Reports buffer number.
+ *  set l [$buf get {n}]	# Get buffer line {n} as a string.
+ *  set L [$buf get {n} {m}]	# Get lines {n} through {m} as a list.
+ *  $buf count			# Reports number of lines in buffer.
+ *  $buf last			# Reports number of last line in buffer.
+ *  $buf delete {n}		# Delete line {n}.
+ *  $buf delete {n} {m}		# Delete lines {n} through {m}.
+ *  $buf set {n} {l}		# Set line {n} to string {l}.
+ *  $buf set {n} {m} {L}	# Set lines {n} through {m} from list {L}.
+ *				# Delete/inserts lines as appropriate.
+ *  $buf option {opt} [val]	# Get/Set vim option in context of $buf.
+ *  $buf command {cmd}		# Execute ex command in context of $buf
+ *  $buf expr {cmd}		# Evaluate vim expression in context of $buf.
+ *  array set pos [$buf mark {m}]   # Get position of mark.
+ *  $buf append {n} {str}	# Append string {str} to buffer,after line {n}.
+ *  $buf insert {n} {str}	# Insert string {str} in buffer as line {n}.
+ *  $buf delcmd {cmd}		# Register callback command for deleted buffer.
+ *  set wl [$buf windows]	# Get list of Tcl commands for all windows of
+ *				# this buffer.
+TODO:
+ *  ::vim::buffer new		#   create new buffer + Tcl command
+ */
+
+#include "vim.h"
+#undef EXTERN			/* tcl.h defines it too */
+
+#ifdef DYNAMIC_TCL
+# define USE_TCL_STUBS /* use tcl's stubs mechanism */
+#endif
+
+#include <tcl.h>
+#include <errno.h>
+#include <string.h>
+
+typedef struct
+{
+    Tcl_Interp *interp;
+    int range_start, range_end;
+    int lbase;
+    char *curbuf, *curwin;
+} tcl_info;
+
+static tcl_info tclinfo = { NULL, 0, 0, 0, NULL, NULL };
+
+#define VAR_RANGE1	"::vim::range(start)"
+#define VAR_RANGE2	"::vim::range(begin)"
+#define VAR_RANGE3	"::vim::range(end)"
+#define VAR_CURBUF	"::vim::current(buffer)"
+#define VAR_CURWIN	"::vim::current(window)"
+#define VAR_LBASE	"::vim::lbase"
+#define VAR_CURLINE	"line"
+#define VAR_CURLNUM	"lnum"
+#define VARNAME_SIZE	64
+
+#define row2tcl(x)  ((x) - (tclinfo.lbase==0))
+#define row2vim(x)  ((x) + (tclinfo.lbase==0))
+#define col2tcl(x)  ((x) + (tclinfo.lbase!=0))
+#define col2vim(x)  ((x) - (tclinfo.lbase!=0))
+
+
+#define VIMOUT	((ClientData)1)
+#define VIMERR	((ClientData)2)
+
+/*
+ *  List of Tcl interpreters who reference a vim window or buffer.
+ *  Each buffer and window has it's own list in the tcl_ref struct member.
+ *  We need this because Tcl can create sub-interpreters with the "interp"
+ *  command, and each interpreter can reference all windows and buffers.
+ */
+struct ref
+{
+    struct ref	*next;
+
+    Tcl_Interp	*interp;
+    Tcl_Command cmd;	    /* Tcl command that represents this object */
+    Tcl_Obj	*delcmd;    /* Tcl command to call when object is being del. */
+    void	*vimobj;    /* Vim window or buffer (win_T* or buf_T*) */
+};
+static char * tclgetbuffer _ANSI_ARGS_((Tcl_Interp *interp, buf_T *buf));
+static char * tclgetwindow _ANSI_ARGS_((Tcl_Interp *interp, win_T *win));
+static int tclsetdelcmd _ANSI_ARGS_((Tcl_Interp *interp, struct ref *reflist, void *vimobj, Tcl_Obj *delcmd));
+static int tclgetlinenum _ANSI_ARGS_ ((Tcl_Interp *interp, Tcl_Obj *obj, int *valueP, buf_T *buf));
+static win_T *tclfindwin _ANSI_ARGS_ ((buf_T *buf));
+static int tcldoexcommand _ANSI_ARGS_ ((Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[], int objn));
+static int tclsetoption _ANSI_ARGS_ ((Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[], int objn));
+static int tclvimexpr _ANSI_ARGS_ ((Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[], int objn));
+static void tcldelthisinterp _ANSI_ARGS_ ((void));
+
+static int vimerror _ANSI_ARGS_((Tcl_Interp *interp));
+static void tclmsg _ANSI_ARGS_((char *text));
+static void tclerrmsg _ANSI_ARGS_((char *text));
+static void tclupdatevars _ANSI_ARGS_((void));
+
+static struct ref refsdeleted;	/* dummy object for deleted ref list */
+
+/*****************************************************************************
+ * TCL interface manager
+ ****************************************************************************/
+
+#if defined(DYNAMIC_TCL) || defined(PROTO)
+# ifndef DYNAMIC_TCL_DLL
+#  define DYNAMIC_TCL_DLL "tcl83.dll"
+# endif
+# ifndef DYNAMIC_TCL_VER
+#  define DYNAMIC_TCL_VER "8.3"
+# endif
+
+# ifndef  DYNAMIC_TCL /* Just generating prototypes */
+typedef int HANDLE;
+# endif
+
+/*
+ * Declare HANDLE for perl.dll and function pointers.
+ */
+static HANDLE hTclLib = NULL;
+Tcl_Interp* (*dll_Tcl_CreateInterp)();
+
+/*
+ * Table of name to function pointer of tcl.
+ */
+#define TCL_PROC FARPROC
+static struct {
+    char* name;
+    TCL_PROC* ptr;
+} tcl_funcname_table[] = {
+    {"Tcl_CreateInterp", (TCL_PROC*)&dll_Tcl_CreateInterp},
+    {NULL, NULL},
+};
+
+/*
+ * Make all runtime-links of tcl.
+ *
+ * 1. Get module handle using LoadLibraryEx.
+ * 2. Get pointer to perl function by GetProcAddress.
+ * 3. Repeat 2, until get all functions will be used.
+ *
+ * Parameter 'libname' provides name of DLL.
+ * Return OK or FAIL.
+ */
+    static int
+tcl_runtime_link_init(char *libname, int verbose)
+{
+    int i;
+
+    if (hTclLib)
+	return OK;
+    if (!(hTclLib = LoadLibraryEx(libname, NULL, 0)))
+    {
+	if (verbose)
+	    EMSG2(_(e_loadlib), libname);
+	return FAIL;
+    }
+    for (i = 0; tcl_funcname_table[i].ptr; ++i)
+    {
+	if (!(*tcl_funcname_table[i].ptr = GetProcAddress(hTclLib,
+			tcl_funcname_table[i].name)))
+	{
+	    FreeLibrary(hTclLib);
+	    hTclLib = NULL;
+	    if (verbose)
+		EMSG2(_(e_loadfunc), tcl_funcname_table[i].name);
+	    return FAIL;
+	}
+    }
+    return OK;
+}
+#endif /* defined(DYNAMIC_TCL) || defined(PROTO) */
+
+#ifdef DYNAMIC_TCL
+static char *find_executable_arg = NULL;
+#endif
+
+    void
+vim_tcl_init(arg)
+    char	*arg;
+{
+#ifndef DYNAMIC_TCL
+    Tcl_FindExecutable(arg);
+#else
+    find_executable_arg = arg;
+#endif
+}
+
+#if defined(DYNAMIC_TCL) || defined(PROTO)
+
+static int stubs_initialized = FALSE;
+
+/*
+ * Return TRUE if the TCL interface can be used.
+ */
+    int
+tcl_enabled(verbose)
+    int		verbose;
+{
+    if (!stubs_initialized && find_executable_arg != NULL
+	    && tcl_runtime_link_init(DYNAMIC_TCL_DLL, verbose) == OK)
+    {
+	Tcl_Interp *interp;
+
+	if (interp = dll_Tcl_CreateInterp())
+	{
+	    if (Tcl_InitStubs(interp, DYNAMIC_TCL_VER, 0))
+	    {
+		Tcl_FindExecutable(find_executable_arg);
+		Tcl_DeleteInterp(interp);
+		stubs_initialized = TRUE;
+	    }
+	    /* FIXME: When Tcl_InitStubs() was failed, how delete interp? */
+	}
+    }
+    return stubs_initialized;
+}
+#endif
+
+    void
+tcl_end()
+{
+#ifdef DYNAMIC_TCL
+    if (hTclLib)
+    {
+	FreeLibrary(hTclLib);
+	hTclLib = NULL;
+    }
+#endif
+}
+
+/****************************************************************************
+  Tcl commands
+ ****************************************************************************/
+
+/*
+ * Replace standard "exit" and "catch" commands.
+ *
+ * This is a design flaw in Tcl -  the standard "exit" command just calls
+ * exit() and kills the application.  It should return TCL_EXIT to the
+ * app, which then decides if it wants to terminate or not.  In our case,
+ * we just delete the Tcl interpreter (and create a new one with the next
+ * :tcl command).
+ */
+#define TCL_EXIT	5
+
+/* ARGSUSED */
+    static int
+exitcmd(dummy, interp, objc, objv)
+    ClientData dummy;
+    Tcl_Interp *interp;
+    int objc;
+    Tcl_Obj *CONST objv[];
+{
+    int value = 0;
+
+    switch (objc)
+    {
+	case 2:
+	    if (Tcl_GetIntFromObj(interp, objv[1], &value) != TCL_OK)
+		break;
+	    /* FALLTHROUGH */
+	case 1:
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(value));
+	    return TCL_EXIT;
+	default:
+	    Tcl_WrongNumArgs(interp, 1, objv, "?returnCode?");
+    }
+    return TCL_ERROR;
+}
+
+/* ARGSUSED */
+    static int
+catchcmd(dummy, interp, objc, objv)
+    ClientData	dummy;
+    Tcl_Interp	*interp;
+    int		objc;
+    Tcl_Obj	*CONST objv[];
+{
+    char    *varname = NULL;
+    int	    result;
+
+    switch (objc)
+    {
+	case 3:
+	    varname = Tcl_GetStringFromObj(objv[2], NULL);
+	    /* fallthrough */
+	case 2:
+	    Tcl_ResetResult(interp);
+	    Tcl_AllowExceptions(interp);
+	    result = Tcl_EvalObj(interp, objv[1]);
+	    if (result == TCL_EXIT)
+		return result;
+	    if (varname)
+	    {
+		if (Tcl_SetVar(interp, varname, Tcl_GetStringResult(interp), 0) == NULL)
+		{
+		    Tcl_SetResult(interp, "couldn't save command result in variable", TCL_STATIC);
+		    return TCL_ERROR;
+		}
+	    }
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(result));
+	    return TCL_OK;
+	default:
+	    Tcl_WrongNumArgs(interp, 1, objv, "command ?varName?");
+    }
+    return TCL_ERROR;
+}
+
+/*
+ *  "::vim::beep" - what Vi[m] does best :-)
+ */
+/* ARGSUSED */
+    static int
+beepcmd(dummy, interp, objc, objv)
+    ClientData dummy;
+    Tcl_Interp *interp;
+    int objc;
+    Tcl_Obj *CONST objv[];
+{
+    if (objc != 1)
+    {
+	Tcl_WrongNumArgs(interp, 1, objv, NULL);
+	return TCL_ERROR;
+    }
+    vim_beep();
+    return TCL_OK;
+}
+
+/*
+ *  "::vim::buffer list" - create a list of buffer commands.
+ *  "::vim::bufffer {N}" - create buffer command for buffer N.
+ *  "::vim::buffer new" - create a new buffer (not implemented)
+ */
+/* ARGSUSED */
+    static int
+buffercmd(dummy, interp, objc, objv)
+    ClientData dummy;
+    Tcl_Interp *interp;
+    int objc;
+    Tcl_Obj *CONST objv[];
+{
+    char	*name;
+    buf_T	*buf;
+    Tcl_Obj	*resobj;
+    int		err, n, idx;
+
+    enum {BCMD_EXISTS, BCMD_LIST};
+    static char *bcmdoptions[] =
+    {
+	"exists", "list", (char *)0
+    };
+
+    if (objc < 2)
+    {
+	Tcl_WrongNumArgs(interp, 1, objv, "option");
+	return TCL_ERROR;
+    }
+    err = Tcl_GetIntFromObj(interp, objv[1], &n);
+    if (err == TCL_OK)
+    {
+	if (objc != 2)
+	{
+	    Tcl_WrongNumArgs(interp, 1, objv, "bufNumber");
+	    return TCL_ERROR;
+	}
+	for (buf = firstbuf; buf != NULL; buf = buf->b_next)
+	{
+	    if (buf->b_fnum == n)
+	    {
+		name = tclgetbuffer(interp, buf);
+		if (name == NULL)
+		    return TCL_ERROR;
+		Tcl_SetResult(interp, name, TCL_VOLATILE);
+		return TCL_OK;
+	    }
+	}
+	Tcl_SetResult(interp, _("invalid buffer number"), TCL_STATIC);
+	return TCL_ERROR;
+    }
+    Tcl_ResetResult(interp); /* clear error from Tcl_GetIntFromObj */
+
+    err = Tcl_GetIndexFromObj(interp, objv[1], bcmdoptions, "option", 0, &idx);
+    if (err != TCL_OK)
+	return err;
+    switch (idx)
+    {
+	case BCMD_LIST:
+	    if (objc != 2)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, "");
+		err = TCL_ERROR;
+		break;
+	    }
+	    for (buf = firstbuf; buf != NULL; buf = buf->b_next)
+	    {
+		name = tclgetbuffer(interp, buf);
+		if (name == NULL)
+		{
+		    err = TCL_ERROR;
+		    break;
+		}
+		Tcl_AppendElement(interp, name);
+	    }
+	    break;
+
+	case BCMD_EXISTS:
+	    if (objc != 3)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, "bufNumber");
+		err = TCL_ERROR;
+		break;
+	    }
+	    err = Tcl_GetIntFromObj(interp, objv[2], &n);
+	    if (err == TCL_OK)
+	    {
+		buf = buflist_findnr(n);
+		resobj = Tcl_NewIntObj(buf != NULL);
+		Tcl_SetObjResult(interp, resobj);
+	    }
+	    break;
+
+	default:
+	    Tcl_SetResult(interp, _("not implemented yet"), TCL_STATIC);
+	    err = TCL_ERROR;
+    }
+    return err;
+}
+
+/*
+ * "::vim::window list" - create list of window commands.
+ */
+/* ARGSUSED */
+    static int
+windowcmd(dummy, interp, objc, objv)
+    ClientData	dummy;
+    Tcl_Interp	*interp;
+    int		objc;
+    Tcl_Obj	*CONST objv[];
+{
+    char	*what, *string;
+    win_T	*win;
+
+    if (objc != 2)
+    {
+	Tcl_WrongNumArgs(interp, 1, objv, "option");
+	return TCL_ERROR;
+    }
+    what = Tcl_GetStringFromObj(objv[1], NULL);
+    if (strcmp(what, "list") == 0)
+    {
+	FOR_ALL_WINDOWS(win)
+	{
+	    string = tclgetwindow(interp, win);
+	    if (string == NULL)
+		return TCL_ERROR;
+	    Tcl_AppendElement(interp, string);
+	}
+	return TCL_OK;
+    }
+    Tcl_SetResult(interp, _("unknown option"), TCL_STATIC);
+    return TCL_ERROR;
+}
+
+/*
+ * flags for bufselfcmd and winselfcmd to indicate outstanding actions.
+ */
+#define FL_UPDATE_SCREEN	(1<<0)
+#define FL_UPDATE_CURBUF	(1<<1)
+#define FL_ADJUST_CURSOR	(1<<2)
+
+/*
+ * This function implements the buffer commands.
+ */
+    static int
+bufselfcmd(ref, interp, objc, objv)
+    ClientData	ref;
+    Tcl_Interp	*interp;
+    int		objc;
+    Tcl_Obj	*CONST objv[];
+{
+    int		opt, err, idx, flags;
+    int		val1, val2, n, i;
+    buf_T	*buf, *savebuf;
+    win_T	*win, *savewin;
+    Tcl_Obj	*resobj;
+    pos_T	*pos;
+    char	*line;
+
+    enum
+    {
+	BUF_APPEND, BUF_COMMAND, BUF_COUNT, BUF_DELCMD, BUF_DELETE, BUF_EXPR,
+	BUF_GET, BUF_INSERT, BUF_LAST, BUF_MARK, BUF_NAME, BUF_NUMBER,
+	BUF_OPTION, BUF_SET, BUF_WINDOWS
+    };
+    static char *bufoptions[] =
+    {
+	"append", "command", "count", "delcmd", "delete", "expr",
+	"get", "insert", "last", "mark", "name", "number",
+	"option", "set", "windows", (char *)0
+    };
+
+    if (objc < 2)
+    {
+	Tcl_WrongNumArgs(interp, 1, objv, "option ?arg ...?");
+	return TCL_ERROR;
+    }
+
+    err = Tcl_GetIndexFromObj(interp, objv[1], bufoptions, "option", 0, &idx);
+    if (err != TCL_OK)
+	return err;
+
+    buf = (buf_T *)((struct ref *)ref)->vimobj;
+    savebuf = curbuf;  curbuf = buf;
+    savewin = curwin;  curwin = tclfindwin(buf);
+    flags = 0;
+    opt = 0;
+
+    switch (idx)
+    {
+	case BUF_COMMAND:
+	    err = tcldoexcommand(interp, objc, objv, 2);
+	    flags |= FL_UPDATE_SCREEN;
+	    break;
+
+	case BUF_OPTION:
+	    err = tclsetoption(interp, objc, objv, 2);
+	    flags |= FL_UPDATE_SCREEN;
+	    break;
+
+	case BUF_EXPR:
+	    err = tclvimexpr(interp, objc, objv, 2);
+	    break;
+
+	case BUF_NAME:
+	    /*
+	     *	Get filename of buffer.
+	     */
+	    if (objc != 2)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, NULL);
+		err = TCL_ERROR;
+		break;
+	    }
+	    if (buf->b_ffname)
+		Tcl_SetResult(interp, (char *)buf->b_ffname, TCL_VOLATILE);
+	    else
+		Tcl_SetResult(interp, "", TCL_STATIC);
+	    break;
+
+	case BUF_LAST:
+	    /*
+	     * Get line number of last line.
+	     */
+	    opt = 1;
+	    /* fallthrough */
+	case BUF_COUNT:
+	    /*
+	     * Get number of lines in buffer.
+	     */
+	    if (objc != 2)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, NULL);
+		err = TCL_ERROR;
+		break;
+	    }
+	    val1 = (int)buf->b_ml.ml_line_count;
+	    if (opt)
+		val1 = row2tcl(val1);
+
+	    resobj = Tcl_NewIntObj(val1);
+	    Tcl_SetObjResult(interp, resobj);
+	    break;
+
+	case BUF_NUMBER:
+	    /*
+	     * Get buffer's number.
+	     */
+	    if (objc != 2)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, NULL);
+		err = TCL_ERROR;
+		break;
+	    }
+	    resobj = Tcl_NewIntObj((int)buf->b_fnum);
+	    Tcl_SetObjResult(interp, resobj);
+	    break;
+
+	case BUF_GET:
+	    if (objc != 3 && objc != 4)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, "lineNumber ?lineNumber?");
+		err = TCL_ERROR;
+		break;
+	    }
+	    err = tclgetlinenum(interp, objv[2], &val1, buf);
+	    if (err != TCL_OK)
+		break;
+	    if (objc == 4)
+	    {
+		err = tclgetlinenum(interp, objv[3], &val2, buf);
+		if (err != TCL_OK)
+		    break;
+		if (val1 > val2)
+		{
+		    n = val1; val1 = val2; val2 = n;
+		}
+		Tcl_ResetResult(interp);
+
+		for (n = val1; n <= val2 && err == TCL_OK; n++)
+		{
+		    line = (char *)ml_get_buf(buf, (linenr_T)n, FALSE);
+		    if (line)
+			Tcl_AppendElement(interp, line);
+		    else
+			err = TCL_ERROR;
+		}
+	    }
+	    else {  /* objc == 3 */
+		line = (char *)ml_get_buf(buf, (linenr_T)val1, FALSE);
+		Tcl_SetResult(interp, line, TCL_VOLATILE);
+	    }
+	    break;
+
+	case BUF_SET:
+	    if (objc != 4 && objc != 5)
+	    {
+		Tcl_WrongNumArgs(interp, 3, objv, "lineNumber ?lineNumber? stringOrList");
+		err = TCL_ERROR;
+		break;
+	    }
+	    err = tclgetlinenum(interp, objv[2], &val1, buf);
+	    if (err != TCL_OK)
+		return TCL_ERROR;
+	    if (objc == 4)
+	    {
+		/*
+		 *  Replace one line with a string.
+		 *	$buf set {n} {string}
+		 */
+		line = Tcl_GetStringFromObj(objv[3], NULL);
+		if (u_savesub((linenr_T)val1) != OK)
+		{
+		    Tcl_SetResult(interp, _("cannot save undo information"), TCL_STATIC);
+		    err = TCL_ERROR;
+		}
+		else
+		if (ml_replace((linenr_T)val1, (char_u *)line, TRUE) != OK)
+		{
+		    Tcl_SetResult(interp, _("cannot replace line"), TCL_STATIC);
+		    err = TCL_ERROR;
+		}
+		else
+		{
+		    changed_bytes((linenr_T)val1, 0);
+		    flags |= FL_UPDATE_CURBUF;
+		}
+		break;
+	    }
+	    else
+	    {
+		/*
+		 * Replace several lines with the elements of a Tcl list.
+		 *	$buf set {n} {m} {list}
+		 * If the list contains more than {m}-{n}+1 elements, they
+		 * are * inserted after line {m}.  If the list contains fewer
+		 * elements, * the lines from {n}+length({list}) through {m}
+		 * are deleted.
+		 */
+		int	    lc;
+		Tcl_Obj	    **lv;
+
+		err = tclgetlinenum(interp, objv[3], &val2, buf);
+		if (err != TCL_OK)
+		    break;
+		err = Tcl_ListObjGetElements(interp, objv[4], &lc, &lv);
+		if (err != TCL_OK)
+		    break;
+		if (val1 > val2)
+		{
+		    n = val1;
+		    val1 = val2;
+		    val2 = n;
+		}
+
+		n = val1;
+		if (u_save((linenr_T)(val1 - 1), (linenr_T)(val2 + 1)) != OK)
+		{
+		    Tcl_SetResult(interp, _("cannot save undo information"),
+								  TCL_STATIC);
+		    err = TCL_ERROR;
+		    break;
+		}
+		flags |= FL_UPDATE_CURBUF;
+
+		for (i = 0; i < lc && n <= val2; i++)
+		{
+		    line = Tcl_GetStringFromObj(lv[i], NULL);
+		    if (ml_replace((linenr_T)n, (char_u *)line, TRUE) != OK)
+			goto setListError;
+		    ++n;
+		}
+		if (i < lc)
+		{
+		    /* append lines */
+		    do
+		    {
+			line = Tcl_GetStringFromObj(lv[i], NULL);
+			if (ml_append((linenr_T)(n - 1),
+					      (char_u *)line, 0, FALSE) != OK)
+			    goto setListError;
+			++n;
+			++i;
+		    } while (i < lc);
+		}
+		else if (n <= val2)
+		{
+		    /* did not replace all lines, delete */
+		    i = n;
+		    do
+		    {
+			if (ml_delete((linenr_T)i, FALSE) != OK)
+			    goto setListError;
+			++n;
+		    } while (n <= val2);
+		}
+		lc -= val2 - val1 + 1;	/* number of lines to be replaced */
+		mark_adjust((linenr_T)val1, (linenr_T)val2, (long)MAXLNUM,
+								    (long)lc);
+		changed_lines((linenr_T)val1, 0, (linenr_T)val2 + 1, (long)lc);
+		break;
+    setListError:
+		u_undo(1);  /* ??? */
+		Tcl_SetResult(interp, _("cannot set line(s)"), TCL_STATIC);
+		err = TCL_ERROR;
+	    }
+	    break;
+
+	case BUF_DELETE:
+	    if (objc != 3  &&  objc != 4)
+	    {
+		Tcl_WrongNumArgs(interp, 3, objv, "lineNumber ?lineNumber?");
+		err = TCL_ERROR;
+		break;
+	    }
+	    err = tclgetlinenum(interp, objv[2], &val1, buf);
+	    if (err != TCL_OK)
+		break;
+	    val2 = val1;
+	    if (objc == 4)
+	    {
+		err = tclgetlinenum(interp, objv[3], &val2, buf);
+		if (err != TCL_OK)
+		    return err;
+		if (val1 > val2)
+		{
+		    i = val1; val1 = val2; val2 = i;
+		}
+	    }
+	    n = val2 - val1 + 1;
+	    if (u_savedel((linenr_T)val1, (long)n) != OK)
+	    {
+		Tcl_SetResult(interp, _("cannot save undo information"),
+								  TCL_STATIC);
+		err = TCL_ERROR;
+		break;
+	    }
+	    for (i = 0; i < n; i++)
+	    {
+		ml_delete((linenr_T)val1, FALSE);
+		err = vimerror(interp);
+		if (err != TCL_OK)
+		    break;
+	    }
+	    if (i > 0)
+		deleted_lines_mark((linenr_T)val1, (long)i);
+	    flags |= FL_ADJUST_CURSOR|FL_UPDATE_SCREEN;
+	    break;
+
+	case BUF_MARK:
+	    if (objc != 3)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, "markName");
+		err = TCL_ERROR;
+		break;
+	    }
+	    line = Tcl_GetStringFromObj(objv[2], NULL);
+
+	    pos = NULL;
+	    if (line[0] != '\0'  &&  line[1] == '\0')
+	    {
+		pos = getmark(line[0], FALSE);
+	    }
+	    if (pos == NULL)
+	    {
+		Tcl_SetResult(interp, _("invalid mark name"), TCL_STATIC);
+		err = TCL_ERROR;
+		break;
+	    }
+	    err = vimerror(interp);
+	    if (err != TCL_OK)
+		break;
+	    if (pos->lnum <= 0)
+	    {
+		Tcl_SetResult(interp, _("mark not set"), TCL_STATIC);
+		err = TCL_ERROR;
+	    }
+	    else
+	    {
+		char rbuf[64];
+		sprintf(rbuf, _("row %d column %d"), (int)row2tcl(pos->lnum), (int)col2tcl(pos->col));
+		Tcl_SetResult(interp, rbuf, TCL_VOLATILE);
+	    }
+	    break;
+
+	case BUF_INSERT:
+	    opt = 1;
+	    /* fallthrough */
+	case BUF_APPEND:
+	    if (objc != 4)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, "lineNum text");
+		err = TCL_ERROR;
+		break;
+	    }
+	    err = tclgetlinenum(interp, objv[2], &val1, buf);
+	    if (err != TCL_OK)
+		break;
+	    if (opt)
+		--val1;
+	    if (u_save((linenr_T)val1, (linenr_T)(val1+1)) != OK)
+	    {
+		Tcl_SetResult(interp, _("cannot save undo information"), TCL_STATIC);
+		err = TCL_ERROR;
+		break;
+	    }
+
+	    line = Tcl_GetStringFromObj(objv[3], NULL);
+	    if (ml_append((linenr_T)val1, (char_u *)line, 0, FALSE) != OK)
+	    {
+		Tcl_SetResult(interp, _("cannot insert/append line"), TCL_STATIC);
+		err = TCL_ERROR;
+		break;
+	    }
+	    appended_lines_mark((linenr_T)val1, 1L);
+	    flags |= FL_UPDATE_SCREEN;
+	    break;
+
+	case BUF_WINDOWS:
+	    /*
+	     * Return list of window commands.
+	     */
+	    if (objc != 2)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, NULL);
+		err = TCL_ERROR;
+		break;
+	    }
+	    Tcl_ResetResult(interp);
+	    FOR_ALL_WINDOWS(win)
+	    {
+		if (win->w_buffer == buf)
+		{
+		    line = tclgetwindow(interp, win);
+		    if (line != NULL)
+			Tcl_AppendElement(interp, line);
+		    else
+		    {
+			err = TCL_ERROR;
+			break;
+		    }
+		}
+	    }
+	    break;
+
+	case BUF_DELCMD:
+	    /*
+	     * Register deletion callback.
+	     * TODO: Should be able to register multiple callbacks
+	     */
+	    if (objc != 3)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, "command");
+		err = TCL_ERROR;
+		break;
+	    }
+	    err = tclsetdelcmd(interp, buf->tcl_ref, (void *)buf, objv[2]);
+	    break;
+
+	default:
+	    Tcl_SetResult(interp, _("not implemented yet"), TCL_STATIC);
+	    err = TCL_ERROR;
+    }
+
+    if (flags & FL_UPDATE_CURBUF)
+	redraw_curbuf_later(NOT_VALID);
+    curbuf = savebuf;
+    curwin = savewin;
+    if (flags & FL_ADJUST_CURSOR)
+	check_cursor();
+    if (flags & (FL_UPDATE_SCREEN | FL_UPDATE_CURBUF))
+	update_screen(NOT_VALID);
+
+    return err;
+}
+
+/*
+ * This function implements the window commands.
+ */
+    static int
+winselfcmd(ref, interp, objc, objv)
+    ClientData	ref;
+    Tcl_Interp	*interp;
+    int		objc;
+    Tcl_Obj	*CONST objv[];
+{
+    int		err, idx, flags;
+    int		val1, val2;
+    Tcl_Obj	*resobj;
+    win_T	*savewin, *win;
+    buf_T	*savebuf;
+    char	*str;
+
+    enum
+    {
+	WIN_BUFFER, WIN_COMMAND, WIN_CURSOR, WIN_DELCMD, WIN_EXPR,
+	WIN_HEIGHT, WIN_OPTION
+    };
+    static char *winoptions[] =
+    {
+	"buffer", "command", "cursor", "delcmd", "expr",
+	"height", "option", (char *)0
+    };
+
+    if (objc < 2)
+    {
+	Tcl_WrongNumArgs(interp, 1, objv, "option ?arg ...?");
+	return TCL_ERROR;
+    }
+
+    err = Tcl_GetIndexFromObj(interp, objv[1], winoptions, "option", 0,  &idx);
+    if (err != TCL_OK)
+	return TCL_ERROR;
+
+    win = (win_T *)((struct ref *)ref)->vimobj;
+    savewin = curwin;  curwin = win;
+    savebuf = curbuf;  curbuf = win->w_buffer;
+    flags = 0;
+
+    switch (idx)
+    {
+	case WIN_OPTION:
+	    err = tclsetoption(interp, objc, objv, 2);
+	    flags |= FL_UPDATE_SCREEN;
+	    break;
+
+	case WIN_COMMAND:
+	    err = tcldoexcommand(interp, objc, objv, 2);
+	    flags |= FL_UPDATE_SCREEN;
+	    break;
+
+	case WIN_EXPR:
+	    err = tclvimexpr(interp, objc, objv, 2);
+	    break;
+
+	case WIN_HEIGHT:
+	    if (objc == 3)
+	    {
+		err = Tcl_GetIntFromObj(interp, objv[2], &val1);
+		if (err != TCL_OK)
+		    break;
+#ifdef FEAT_GUI
+		need_mouse_correct = TRUE;
+#endif
+		win_setheight(val1);
+		err = vimerror(interp);
+		if (err != TCL_OK)
+		    break;
+	    }
+	    else
+	    if (objc != 2)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, "?value?");
+		err = TCL_ERROR;
+		break;
+	    }
+
+	    resobj = Tcl_NewIntObj((int)(win->w_height));
+	    Tcl_SetObjResult(interp, resobj);
+	    break;
+
+	case WIN_BUFFER:
+	    if (objc != 2)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, NULL);
+		err = TCL_ERROR;
+		break;
+	    }
+	    str = tclgetbuffer(interp, win->w_buffer);
+	    if (str)
+		Tcl_SetResult(interp, str, TCL_VOLATILE);
+	    else
+		err = TCL_ERROR;
+	    break;
+
+	case WIN_DELCMD:
+	    if (objc != 3)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, "command");
+		err = TCL_ERROR;
+		break;
+	    }
+	    err = tclsetdelcmd(interp, win->tcl_ref, (void *)win, objv[2]);
+	    break;
+
+	case WIN_CURSOR:
+	    if (objc > 4)
+	    {
+		Tcl_WrongNumArgs(interp, 2, objv, "?arg1 ?arg2??");
+		err = TCL_ERROR;
+		break;
+	    }
+	    if (objc == 2)
+	    {
+		char buf[64];
+		sprintf(buf, _("row %d column %d"), (int)row2tcl(win->w_cursor.lnum), (int)col2tcl(win->w_cursor.col));
+		Tcl_SetResult(interp, buf, TCL_VOLATILE);
+		break;
+	    }
+	    else if (objc == 3)
+	    {
+		Tcl_Obj *part, *var;
+
+		part = Tcl_NewStringObj("row", -1);
+		var = Tcl_ObjGetVar2(interp, objv[2], part, TCL_LEAVE_ERR_MSG);
+		if (var == NULL)
+		{
+		    err = TCL_ERROR;
+		    break;
+		}
+		err = tclgetlinenum(interp, var, &val1, win->w_buffer);
+		if (err != TCL_OK)
+		    break;
+		part = Tcl_NewStringObj("column", -1);
+		var = Tcl_ObjGetVar2(interp, objv[2], part, TCL_LEAVE_ERR_MSG);
+		if (var == NULL)
+		{
+		    err = TCL_ERROR;
+		    break;
+		}
+		err = Tcl_GetIntFromObj(interp, var, &val2);
+		if (err != TCL_OK)
+		    break;
+	    }
+	    else {  /* objc == 4 */
+		err = tclgetlinenum(interp, objv[2], &val1, win->w_buffer);
+		if (err != TCL_OK)
+		    break;
+		err = Tcl_GetIntFromObj(interp, objv[3], &val2);
+		if (err != TCL_OK)
+		    break;
+	    }
+	    /* TODO: should check column */
+	    win->w_cursor.lnum = val1;
+	    win->w_cursor.col = col2vim(val2);
+	    flags |= FL_UPDATE_SCREEN;
+	    break;
+
+	default:
+	    Tcl_SetResult(interp, _("not implemented yet"), TCL_STATIC);
+	    break;
+    }
+
+    curwin = savewin;
+    curbuf = savebuf;
+    if (flags & FL_UPDATE_SCREEN)
+	update_screen(NOT_VALID);
+
+    return err;
+}
+
+
+/* ARGSUSED */
+    static int
+commandcmd(dummy, interp, objc, objv)
+    ClientData	dummy;
+    Tcl_Interp	*interp;
+    int		objc;
+    Tcl_Obj	*CONST objv[];
+{
+    int		err;
+
+    err = tcldoexcommand(interp, objc, objv, 1);
+    update_screen(VALID);
+    return err;
+}
+
+/* ARGSUSED */
+    static int
+optioncmd(dummy, interp, objc, objv)
+    ClientData	dummy;
+    Tcl_Interp	*interp;
+    int		objc;
+    Tcl_Obj	*CONST objv[];
+{
+    int		err;
+
+    err = tclsetoption(interp, objc, objv, 1);
+    update_screen(VALID);
+    return err;
+}
+
+/* ARGSUSED */
+    static int
+exprcmd(dummy, interp, objc, objv)
+    ClientData	dummy;
+    Tcl_Interp	*interp;
+    int		objc;
+    Tcl_Obj	*CONST objv[];
+{
+    return tclvimexpr(interp, objc, objv, 1);
+}
+
+/****************************************************************************
+  Support functions for Tcl commands
+ ****************************************************************************/
+
+/*
+ * Get a line number from 'obj' and convert it to vim's range.
+ */
+    static int
+tclgetlinenum(interp, obj, valueP, buf)
+    Tcl_Interp	*interp;
+    Tcl_Obj	*obj;
+    int		*valueP;
+    buf_T	*buf;
+{
+    int err, i;
+
+    enum { LN_BEGIN, LN_BOTTOM, LN_END, LN_FIRST, LN_LAST, LN_START, LN_TOP };
+
+    static char *keyw[] =
+    {
+	"begin", "bottom", "end", "first", "last", "start", "top", (char *)0
+    };
+
+    err = Tcl_GetIndexFromObj(interp, obj, keyw, "", 0, &i);
+    if (err == TCL_OK)
+    {
+	switch (i)
+	{
+	    case LN_BEGIN:
+	    case LN_FIRST:
+	    case LN_START:
+	    case LN_TOP:
+		*valueP = 1;
+		break;
+	    case LN_BOTTOM:
+	    case LN_END:
+	    case LN_LAST:
+		*valueP = buf->b_ml.ml_line_count;
+		break;
+	}
+	return TCL_OK;
+    }
+    Tcl_ResetResult(interp);
+
+    err = Tcl_GetIntFromObj(interp, obj, &i);
+    if (err != TCL_OK)
+	return err;
+    i = row2vim(i);
+    if (i < 1  ||  i > buf->b_ml.ml_line_count)
+    {
+	Tcl_SetResult(interp, _("line number out of range"), TCL_STATIC);
+	return TCL_ERROR;
+    }
+    *valueP = i;
+    return TCL_OK;
+}
+
+/*
+ * Find the first window in the window list that displays the buffer.
+ */
+    static win_T *
+tclfindwin(buf)
+    buf_T *buf;
+{
+    win_T *win;
+
+    FOR_ALL_WINDOWS(win)
+    {
+	if (win->w_buffer == buf)
+	    return win;
+    }
+    return curwin;  /* keep current window context */
+}
+
+/*
+ * Do-it-all function for "::vim::command", "$buf command" and "$win command".
+ */
+    static int
+tcldoexcommand(interp, objc, objv, objn)
+    Tcl_Interp	*interp;
+    int		objc;
+    Tcl_Obj	*CONST objv[];
+    int		objn;
+{
+    tcl_info	saveinfo;
+    int		err, flag, nobjs;
+    char	*arg;
+
+    nobjs = objc - objn;
+    if (nobjs < 1 || nobjs > 2)
+    {
+	Tcl_WrongNumArgs(interp, objn, objv, "?-quiet? exCommand");
+	return TCL_ERROR;
+    }
+
+    flag = 0;
+    if (nobjs == 2)
+    {
+	arg = Tcl_GetStringFromObj(objv[objn], NULL);
+	if (strcmp(arg, "-quiet") == 0)
+	    flag = 1;
+	else
+	{
+	    Tcl_ResetResult(interp);
+	    Tcl_AppendResult(interp, _("unknown flag: "), arg, (char *)0);
+	    return TCL_ERROR;
+	}
+	++objn;
+    }
+
+    memcpy(&saveinfo, &tclinfo, sizeof(tcl_info));
+    tclinfo.interp = NULL;
+    tclinfo.curwin = NULL;
+    tclinfo.curbuf = NULL;
+
+    arg = Tcl_GetStringFromObj(objv[objn], NULL);
+    if (flag)
+	++emsg_off;
+    do_cmdline_cmd((char_u *)arg);
+    if (flag)
+	--emsg_off;
+    err = vimerror(interp);
+
+    /* If the ex command created a new Tcl interpreter, remove it */
+    if (tclinfo.interp)
+	tcldelthisinterp();
+    memcpy(&tclinfo, &saveinfo, sizeof(tcl_info));
+    tclupdatevars();
+
+    return err;
+}
+
+/*
+ * Do-it-all function for "::vim::option", "$buf option" and "$win option".
+ */
+    static int
+tclsetoption(interp, objc, objv, objn)
+    Tcl_Interp	*interp;
+    int		objc;
+    Tcl_Obj	*CONST objv[];
+    int		objn;
+{
+    int		err, nobjs, idx;
+    char_u	*option;
+    int		isnum;
+    long	lval;
+    char_u	*sval;
+    Tcl_Obj	*resobj;
+
+    enum { OPT_OFF, OPT_ON, OPT_TOGGLE };
+    static char *optkw[] = { "off", "on", "toggle", (char *)0 };
+
+    nobjs = objc - objn;
+    if (nobjs != 1 && nobjs != 2)
+    {
+	Tcl_WrongNumArgs(interp, objn, objv, "vimOption ?value?");
+	return TCL_ERROR;
+    }
+
+    option = (char_u *)Tcl_GetStringFromObj(objv[objn], NULL);
+    ++objn;
+    isnum = get_option_value(option, &lval, &sval, 0);
+    err = TCL_OK;
+    switch (isnum)
+    {
+	case 0:
+	    Tcl_SetResult(interp, (char *)sval, TCL_VOLATILE);
+	    vim_free(sval);
+	    break;
+	case 1:
+	    resobj = Tcl_NewLongObj(lval);
+	    Tcl_SetObjResult(interp, resobj);
+	    break;
+	default:
+	    Tcl_SetResult(interp, _("unknown vimOption"), TCL_STATIC);
+	    return TCL_ERROR;
+    }
+    if (nobjs == 2)
+    {
+	if (isnum)
+	{
+	    sval = NULL;    /* avoid compiler warning */
+	    err = Tcl_GetIndexFromObj(interp, objv[objn], optkw, "", 0, &idx);
+	    if (err != TCL_OK)
+	    {
+		Tcl_ResetResult(interp);
+		err = Tcl_GetLongFromObj(interp, objv[objn], &lval);
+	    }
+	    else
+	    switch (idx)
+	    {
+		case OPT_ON:
+		    lval = 1;
+		    break;
+		case OPT_OFF:
+		    lval = 0;
+		    break;
+		case OPT_TOGGLE:
+		    lval = !lval;
+		    break;
+	    }
+	}
+	else
+	    sval = (char_u *)Tcl_GetStringFromObj(objv[objn], NULL);
+	if (err == TCL_OK)
+	{
+	    set_option_value(option, lval, sval, OPT_LOCAL);
+	    err = vimerror(interp);
+	}
+    }
+    return err;
+}
+
+/*
+ * Do-it-all function for "::vim::expr", "$buf expr" and "$win expr".
+ */
+    static int
+tclvimexpr(interp, objc, objv, objn)
+    Tcl_Interp	*interp;
+    int		objc;
+    Tcl_Obj	*CONST objv[];
+    int		objn;
+{
+#ifdef FEAT_EVAL
+    char	*expr, *str;
+#endif
+    int		err;
+
+    if (objc - objn != 1)
+    {
+	Tcl_WrongNumArgs(interp, objn, objv, "vimExpr");
+	return TCL_ERROR;
+    }
+
+#ifdef FEAT_EVAL
+    expr = Tcl_GetStringFromObj(objv[objn], NULL);
+    str = (char *)eval_to_string((char_u *)expr, NULL);
+    if (str == NULL)
+	Tcl_SetResult(interp, _("invalid expression"), TCL_STATIC);
+    else
+	Tcl_SetResult(interp, str, TCL_VOLATILE);
+    err = vimerror(interp);
+#else
+    Tcl_SetResult(interp, _("expressions disabled at compile time"), TCL_STATIC);
+    err = TCL_ERROR;
+#endif
+
+    return err;
+}
+
+/*
+ * Check for internal vim errors.
+ */
+    static int
+vimerror(interp)
+    Tcl_Interp *interp;
+{
+    if (got_int)
+    {
+	Tcl_SetResult(interp, _("keyboard interrupt"), TCL_STATIC);
+	return TCL_ERROR;
+    }
+    else if (did_emsg)
+    {
+	Tcl_SetResult(interp, _("vim error"), TCL_STATIC);
+	return TCL_ERROR;
+    }
+    return TCL_OK;
+}
+
+/*
+ * Functions that handle the reference lists:
+ *   delref() - callback for Tcl's DeleteCommand
+ *   tclgetref() - find/create Tcl command for a win_T* or buf_T* object
+ *   tclgetwindow() - window frontend for tclgetref()
+ *   tclgetbuffer() - buffer frontend for tclgetref()
+ *   tclsetdelcmd() - add Tcl callback command to a vim object
+ */
+    static void
+delref(cref)
+    ClientData cref;
+{
+    struct ref *ref = (struct ref *)cref;
+
+    if (ref->delcmd)
+    {
+	Tcl_DecrRefCount(ref->delcmd);
+	ref->delcmd = NULL;
+    }
+    ref->interp = NULL;
+}
+
+    static char *
+tclgetref(interp, refstartP, prefix, vimobj, proc)
+    Tcl_Interp	*interp;
+    void	**refstartP;	/* ptr to tcl_ref member of win_T/buf_T struct */
+    char	*prefix;	/* "win" or "buf" */
+    void	*vimobj;	/* win_T* or buf_T* */
+    Tcl_ObjCmdProc *proc;	/* winselfcmd or bufselfcmd */
+{
+    struct ref *ref, *unused = NULL;
+    static char name[VARNAME_SIZE];
+    Tcl_Command cmd;
+
+    ref = (struct ref *)(*refstartP);
+    if (ref == &refsdeleted)
+    {
+	Tcl_SetResult(interp, _("cannot create buffer/window command: object is being deleted"), TCL_STATIC);
+	return NULL;
+    }
+
+    while (ref != NULL)
+    {
+	if (ref->interp == interp)
+	    break;
+	if (ref->interp == NULL)
+	    unused = ref;
+	ref = ref->next;
+    }
+
+    if (ref)
+	sprintf(name, "::vim::%s", Tcl_GetCommandName(interp, ref->cmd));
+    else
+    {
+	if (unused)
+	    ref = unused;
+	else
+	{
+	    ref = (struct ref *)Tcl_Alloc(sizeof(struct ref));
+#if 0	/* Tcl_Alloc either succeeds or does not return */
+	    if (!ref)
+	    {
+		Tcl_SetResult(interp, "out of memory", TCL_STATIC);
+		return NULL;
+	    }
+#endif
+	    ref->interp = NULL;
+	    ref->next = (struct ref *)(*refstartP);
+	    (*refstartP) = (void *)ref;
+	}
+
+	/* This might break on some exotic systems... */
+	sprintf(name, "::vim::%s_%lx", prefix, (unsigned long)vimobj);
+	cmd = Tcl_CreateObjCommand(interp, name, proc,
+	    (ClientData)ref, (Tcl_CmdDeleteProc *)delref);
+	if (!cmd)
+	    return NULL;
+
+	ref->interp = interp;
+	ref->cmd = cmd;
+	ref->delcmd = NULL;
+	ref->vimobj = vimobj;
+    }
+    return name;
+}
+
+    static char *
+tclgetwindow(interp, win)
+    Tcl_Interp	*interp;
+    win_T	*win;
+{
+    return tclgetref(interp, &(win->tcl_ref), "win", (void *)win, winselfcmd);
+}
+
+    static char *
+tclgetbuffer(interp, buf)
+    Tcl_Interp	*interp;
+    buf_T	*buf;
+{
+    return tclgetref(interp, &(buf->tcl_ref), "buf", (void *)buf, bufselfcmd);
+}
+
+    static int
+tclsetdelcmd(interp, reflist, vimobj, delcmd)
+    Tcl_Interp	*interp;
+    struct ref	*reflist;
+    void	*vimobj;
+    Tcl_Obj	*delcmd;
+{
+    if (reflist == &refsdeleted)
+    {
+	Tcl_SetResult(interp, _("cannot register callback command: buffer/window is already being deleted"), TCL_STATIC);
+	return TCL_ERROR;
+    }
+
+    while (reflist != NULL)
+    {
+	if (reflist->interp == interp && reflist->vimobj == vimobj)
+	{
+	    if (reflist->delcmd)
+		Tcl_DecrRefCount(reflist->delcmd);
+	    Tcl_IncrRefCount(delcmd);
+	    reflist->delcmd = delcmd;
+	    return TCL_OK;
+	}
+	reflist = reflist->next;
+    }
+    /* This should never happen.  Famous last word? */
+    EMSG(_("E280: TCL FATAL ERROR: reflist corrupt!? Please report this to vim-dev@vim.org"));
+    Tcl_SetResult(interp, _("cannot register callback command: buffer/window reference not found"), TCL_STATIC);
+    return TCL_ERROR;
+}
+
+
+/*******************************************
+    I/O Channel
+********************************************/
+
+/* ARGSUSED */
+    static int
+channel_close(instance, interp)
+    ClientData	instance;
+    Tcl_Interp	*interp;
+{
+    int		err = 0;
+
+    /* currently does nothing */
+
+    if (instance != VIMOUT && instance != VIMERR)
+    {
+	Tcl_SetErrno(EBADF);
+	err = EBADF;
+    }
+    return err;
+}
+
+/* ARGSUSED */
+    static int
+channel_input(instance, buf, bufsiz, errptr)
+    ClientData	instance;
+    char	*buf;
+    int		bufsiz;
+    int		*errptr;
+{
+
+    /* input is currently not supported */
+
+    Tcl_SetErrno(EINVAL);
+    if (errptr)
+	*errptr = EINVAL;
+    return -1;
+}
+
+    static int
+channel_output(instance, buf, bufsiz, errptr)
+    ClientData	instance;
+    char	*buf;
+    int		bufsiz;
+    int		*errptr;
+{
+    char_u	*str;
+    int		result;
+
+    /* The buffer is not guaranteed to be 0-terminated, and we don't if
+     * there is enough room to add a '\0'.  So we have to create a copy
+     * of the buffer...
+     */
+    str = vim_strnsave((char_u *)buf, bufsiz);
+    if (!str)
+    {
+	Tcl_SetErrno(ENOMEM);
+	if (errptr)
+	    *errptr = ENOMEM;
+	return -1;
+    }
+
+    result = bufsiz;
+    if (instance == VIMOUT)
+	tclmsg((char *)str);
+    else
+    if (instance == VIMERR)
+	tclerrmsg((char *)str);
+    else
+    {
+	Tcl_SetErrno(EBADF);
+	if (errptr)
+	    *errptr = EBADF;
+	result = -1;
+    }
+    vim_free(str);
+    return result;
+}
+
+/* ARGSUSED */
+    static void
+channel_watch(instance, mask)
+    ClientData	instance;
+    int		mask;
+{
+    Tcl_SetErrno(EINVAL);
+}
+
+/* ARGSUSED */
+    static int
+channel_gethandle(instance, direction, handleptr)
+    ClientData	instance;
+    int		direction;
+    ClientData	*handleptr;
+{
+    Tcl_SetErrno(EINVAL);
+    return EINVAL;
+}
+
+
+static Tcl_ChannelType channel_type =
+{
+    "vimmessage",
+    NULL,   /* blockmode */
+    channel_close,
+    channel_input,
+    channel_output,
+    NULL,   /* seek */
+    NULL,   /* set option */
+    NULL,   /* get option */
+    channel_watch,
+    channel_gethandle
+};
+
+/**********************************
+  Interface to vim
+ **********************************/
+
+    static void
+tclupdatevars()
+{
+    char varname[VARNAME_SIZE];	/* must be writeable */
+    char *name;
+
+    strcpy(varname, VAR_RANGE1);
+    Tcl_UpdateLinkedVar(tclinfo.interp, varname);
+    strcpy(varname, VAR_RANGE2);
+    Tcl_UpdateLinkedVar(tclinfo.interp, varname);
+    strcpy(varname, VAR_RANGE3);
+    Tcl_UpdateLinkedVar(tclinfo.interp, varname);
+
+    strcpy(varname, VAR_LBASE);
+    Tcl_UpdateLinkedVar(tclinfo.interp, varname);
+
+    name = tclgetbuffer(tclinfo.interp, curbuf);
+    strcpy(tclinfo.curbuf, name);
+    strcpy(varname, VAR_CURBUF);
+    Tcl_UpdateLinkedVar(tclinfo.interp, varname);
+
+    name = tclgetwindow(tclinfo.interp, curwin);
+    strcpy(tclinfo.curwin, name);
+    strcpy(varname, VAR_CURWIN);
+    Tcl_UpdateLinkedVar(tclinfo.interp, varname);
+}
+
+
+    static int
+tclinit(eap)
+    exarg_T *eap;
+{
+    char varname[VARNAME_SIZE];	/* Tcl_LinkVar requires writeable varname */
+    char *name;
+
+#ifdef DYNAMIC_TCL
+    if (!tcl_enabled(TRUE))
+    {
+	EMSG(_("E571: Sorry, this command is disabled: the Tcl library could not be loaded."));
+	return FAIL;
+    }
+#endif
+
+    if (!tclinfo.interp)
+    {
+	Tcl_Interp *interp;
+	static Tcl_Channel ch1, ch2;
+
+	/* replace stdout and stderr */
+	ch1 = Tcl_CreateChannel(&channel_type, "vimout", VIMOUT, TCL_WRITABLE);
+	ch2 = Tcl_CreateChannel(&channel_type, "vimerr", VIMERR, TCL_WRITABLE);
+	Tcl_SetStdChannel(ch1, TCL_STDOUT);
+	Tcl_SetStdChannel(ch2, TCL_STDERR);
+
+	interp = Tcl_CreateInterp();
+	Tcl_Preserve(interp);
+	if (Tcl_Init(interp) == TCL_ERROR)
+	{
+	    Tcl_Release(interp);
+	    Tcl_DeleteInterp(interp);
+	    return FAIL;
+	}
+#if 0
+	/* VIM sure is interactive */
+	Tcl_SetVar(interp, "tcl_interactive", "1", TCL_GLOBAL_ONLY);
+#endif
+
+	Tcl_SetChannelOption(interp, ch1, "-buffering", "line");
+	Tcl_SetChannelOption(interp, ch2, "-buffering", "line");
+
+	/* replace some standard Tcl commands */
+	Tcl_DeleteCommand(interp, "exit");
+	Tcl_CreateObjCommand(interp, "exit", exitcmd,
+	    (ClientData)NULL, (Tcl_CmdDeleteProc *)NULL);
+	Tcl_DeleteCommand(interp, "catch");
+	Tcl_CreateObjCommand(interp, "catch", catchcmd,
+	    (ClientData)NULL, (Tcl_CmdDeleteProc *)NULL);
+
+	/* new commands, in ::vim namespace */
+	Tcl_CreateObjCommand(interp, "::vim::buffer", buffercmd,
+	    (ClientData)NULL, (Tcl_CmdDeleteProc *)NULL);
+	Tcl_CreateObjCommand(interp, "::vim::window", windowcmd,
+	   (ClientData)NULL, (Tcl_CmdDeleteProc *)NULL);
+	Tcl_CreateObjCommand(interp, "::vim::command", commandcmd,
+	   (ClientData)NULL, (Tcl_CmdDeleteProc *)NULL);
+	Tcl_CreateObjCommand(interp, "::vim::beep", beepcmd,
+	   (ClientData)NULL, (Tcl_CmdDeleteProc *)NULL);
+	Tcl_CreateObjCommand(interp, "::vim::option", optioncmd,
+	   (ClientData)NULL, (Tcl_CmdDeleteProc *)NULL);
+	Tcl_CreateObjCommand(interp, "::vim::expr", exprcmd,
+	   (ClientData)NULL, (Tcl_CmdDeleteProc *)NULL);
+
+	/* "lbase" variable */
+	tclinfo.lbase = 1;
+	strcpy(varname, VAR_LBASE);
+	Tcl_LinkVar(interp, varname, (char *)&tclinfo.lbase, TCL_LINK_INT);
+
+	/* "range" variable */
+	tclinfo.range_start = eap->line1;
+	strcpy(varname, VAR_RANGE1);
+	Tcl_LinkVar(interp, varname, (char *)&tclinfo.range_start, TCL_LINK_INT|TCL_LINK_READ_ONLY);
+	strcpy(varname, VAR_RANGE2);
+	Tcl_LinkVar(interp, varname, (char *)&tclinfo.range_start, TCL_LINK_INT|TCL_LINK_READ_ONLY);
+	tclinfo.range_end   = eap->line2;
+	strcpy(varname, VAR_RANGE3);
+	Tcl_LinkVar(interp, varname, (char *)&tclinfo.range_end, TCL_LINK_INT|TCL_LINK_READ_ONLY);
+
+	/* "current" variable */
+	tclinfo.curbuf = Tcl_Alloc(VARNAME_SIZE);
+	tclinfo.curwin = Tcl_Alloc(VARNAME_SIZE);
+	name = tclgetbuffer(interp, curbuf);
+	strcpy(tclinfo.curbuf, name);
+	strcpy(varname, VAR_CURBUF);
+	Tcl_LinkVar(interp, varname, (char *)&tclinfo.curbuf, TCL_LINK_STRING|TCL_LINK_READ_ONLY);
+	name = tclgetwindow(interp, curwin);
+	strcpy(tclinfo.curwin, name);
+	strcpy(varname, VAR_CURWIN);
+	Tcl_LinkVar(interp, varname, (char *)&tclinfo.curwin, TCL_LINK_STRING|TCL_LINK_READ_ONLY);
+
+	tclinfo.interp = interp;
+    }
+    else
+    {
+	/* Interpreter already exists, just update variables */
+	tclinfo.range_start = row2tcl(eap->line1);
+	tclinfo.range_end = row2tcl(eap->line2);
+	tclupdatevars();
+    }
+    return OK;
+}
+
+    static void
+tclerrmsg(text)
+    char *text;
+{
+    char *next;
+
+    while ((next=strchr(text, '\n')))
+    {
+	*next++ = '\0';
+	EMSG(text);
+	text = next;
+    }
+    if (*text)
+	EMSG(text);
+}
+
+    static void
+tclmsg(text)
+    char *text;
+{
+    char *next;
+
+    while ((next=strchr(text, '\n')))
+    {
+	*next++ = '\0';
+	MSG(text);
+	text = next;
+    }
+    if (*text)
+	MSG(text);
+}
+
+    static void
+tcldelthisinterp()
+{
+    if (!Tcl_InterpDeleted(tclinfo.interp))
+	Tcl_DeleteInterp(tclinfo.interp);
+    Tcl_Release(tclinfo.interp);
+    /* The interpreter is now gets deleted.  All registered commands (esp.
+     * window and buffer commands) are deleted, triggering their deletion
+     * callback, which deletes all refs pointing to this interpreter.
+     * We could garbage-collect the unused ref structs in all windows and
+     * buffers, but unless the user creates hundreds of sub-interpreters
+     * all refering to lots of windows and buffers, this is hardly worth
+     * the effort.  Unused refs are recycled by other interpreters, and
+     * all refs are free'd when the window/buffer gets closed by vim.
+     */
+
+    tclinfo.interp = NULL;
+    Tcl_Free(tclinfo.curbuf);
+    Tcl_Free(tclinfo.curwin);
+    tclinfo.curbuf = tclinfo.curwin = NULL;
+}
+
+    static int
+tclexit(error)
+    int error;
+{
+    int newerr = OK;
+
+    if (error == TCL_EXIT )
+    {
+	int retval;
+	char buf[32];
+	Tcl_Obj *robj;
+
+	robj = Tcl_GetObjResult(tclinfo.interp);
+	if( Tcl_GetIntFromObj(tclinfo.interp, robj, &retval) != TCL_OK )
+	{
+	    EMSG(_("E281: TCL ERROR: exit code is not int!? Please report this to vim-dev@vim.org"));
+	    newerr = FAIL;
+	}
+	else
+	{
+	    sprintf(buf, "E572: exit code %d", retval);
+	    tclerrmsg(buf);
+	    if (retval == 0 )
+	    {
+		did_emsg = 0;
+		newerr = OK;
+	    }
+	    else
+		newerr = FAIL;
+	}
+
+	tcldelthisinterp();
+    }
+    else
+    {
+	char *result;
+
+	result = Tcl_GetStringResult(tclinfo.interp);
+	if (error == TCL_OK)
+	{
+	    tclmsg(result);
+	    newerr = OK;
+	}
+	else
+	{
+	    tclerrmsg(result);
+	    newerr = FAIL;
+	}
+    }
+
+    return newerr;
+}
+
+/*
+ * ":tcl"
+ */
+    void
+ex_tcl(eap)
+    exarg_T *eap;
+{
+    char_u	*script;
+    int		err;
+
+    script = script_get(eap, eap->arg);
+    if (!eap->skip)
+    {
+	err = tclinit(eap);
+	if (err == OK)
+	{
+	    Tcl_AllowExceptions(tclinfo.interp);
+	    if (script == NULL)
+		err = Tcl_Eval(tclinfo.interp, (char *)eap->arg);
+	    else
+		err = Tcl_Eval(tclinfo.interp, (char *)script);
+	    err = tclexit(err);
+	}
+    }
+    vim_free(script);
+}
+
+/*
+ * ":tclfile"
+ */
+    void
+ex_tclfile(eap)
+    exarg_T *eap;
+{
+    char *file = (char *)eap->arg;
+    int err;
+
+    err = tclinit(eap);
+    if (err == OK)
+    {
+	Tcl_AllowExceptions(tclinfo.interp);
+	err = Tcl_EvalFile(tclinfo.interp, file);
+	err = tclexit(err);
+    }
+}
+
+/*
+ * ":tcldo"
+ */
+    void
+ex_tcldo(eap)
+    exarg_T *eap;
+{
+    char	*script, *line;
+    int		err, rs, re, lnum;
+    char	var_lnum[VARNAME_SIZE]; /* must be writeable memory */
+    char	var_line[VARNAME_SIZE];
+    linenr_T	first_line = 0;
+    linenr_T	last_line = 0;
+
+    rs = eap->line1;
+    re = eap->line2;
+    script = (char *)eap->arg;
+    strcpy(var_lnum, VAR_CURLNUM);
+    strcpy(var_line, VAR_CURLINE);
+
+    err = tclinit(eap);
+    if (err != OK)
+	return;
+
+    lnum = row2tcl(rs);
+    Tcl_LinkVar(tclinfo.interp, var_lnum, (char *)&lnum, TCL_LINK_INT|TCL_LINK_READ_ONLY);
+    err = TCL_OK;
+    if (u_save((linenr_T)(rs-1), (linenr_T)(re+1)) != OK)
+    {
+	Tcl_SetResult(tclinfo.interp, _("cannot save undo information"), TCL_STATIC);
+	err = TCL_ERROR;
+    }
+    while (err == TCL_OK  &&  rs <= re)
+    {
+	line = (char *)ml_get_buf(curbuf, (linenr_T)rs, FALSE);
+	if (!line)
+	{
+	    Tcl_SetResult(tclinfo.interp, _("cannot get line"), TCL_STATIC);
+	    err = TCL_ERROR;
+	    break;
+	}
+	Tcl_SetVar(tclinfo.interp, var_line, line, 0);
+	Tcl_AllowExceptions(tclinfo.interp);
+	err = Tcl_Eval(tclinfo.interp, script);
+	if (err != TCL_OK)
+	    break;
+	line = Tcl_GetVar(tclinfo.interp, var_line, 0);
+	if (line)
+	{
+	    if (ml_replace((linenr_T)rs, (char_u *)line, TRUE) != OK)
+	    {
+		Tcl_SetResult(tclinfo.interp, _("cannot replace line"), TCL_STATIC);
+		err = TCL_ERROR;
+		break;
+	    }
+	    if (first_line == 0)
+		first_line = rs;
+	    last_line = rs;
+	}
+	++rs;
+	++lnum;
+	Tcl_UpdateLinkedVar(tclinfo.interp, var_lnum);
+    }
+    if (first_line)
+	changed_lines(first_line, 0, last_line + 1, (long)0);
+
+    Tcl_UnsetVar(tclinfo.interp, var_line, 0);
+    Tcl_UnlinkVar(tclinfo.interp, var_lnum);
+    if (err == TCL_OK)
+	Tcl_ResetResult(tclinfo.interp);
+
+    (void)tclexit(err);
+}
+
+    static void
+tcldelallrefs(ref)
+    struct ref *ref;
+{
+    struct ref	*next;
+    int		err;
+    char	*result;
+
+    while (ref != NULL)
+    {
+	next = ref->next;
+	if (ref->interp)
+	{
+	    if (ref->delcmd)
+	    {
+		err = Tcl_GlobalEvalObj(ref->interp, ref->delcmd);
+		if (err != TCL_OK)
+		{
+		    result = Tcl_GetStringResult(ref->interp);
+		    if (result)
+			tclerrmsg(result);
+		}
+		Tcl_DecrRefCount(ref->delcmd);
+		ref->delcmd = NULL;
+	    }
+	    Tcl_DeleteCommandFromToken(ref->interp, ref->cmd);
+	}
+	Tcl_Free((char *)ref);
+	ref = next;
+    }
+}
+
+    void
+tcl_buffer_free(buf)
+    buf_T *buf;
+{
+    struct ref *reflist;
+
+#ifdef DYNAMIC_TCL
+    if (!stubs_initialized)	/* Not using Tcl, nothing to do. */
+	return;
+#endif
+
+    reflist = (struct ref*)(buf->tcl_ref);
+    if (reflist != &refsdeleted)
+    {
+	buf->tcl_ref = (void *)&refsdeleted;
+	tcldelallrefs(reflist);
+	buf->tcl_ref = NULL;
+    }
+}
+
+#if defined(FEAT_WINDOWS) || defined(PROTO)
+    void
+tcl_window_free(win)
+    win_T *win;
+{
+    struct ref *reflist;
+
+#ifdef DYNAMIC_TCL
+    if (!stubs_initialized)	/* Not using Tcl, nothing to do. */
+	return;
+#endif
+
+    reflist = (struct ref*)(win->tcl_ref);
+    if (reflist != &refsdeleted)
+    {
+	win->tcl_ref = (void *)&refsdeleted;
+	tcldelallrefs(reflist);
+	win->tcl_ref = NULL;
+    }
+}
+#endif
+
+/* The End */