Merge commit '29ccecd87709feda60d191f6aaba324ccad91f55' as 'tcl8.6'

1 files changed, 2027 insertions, 0 deletions

diff --git a/tcl8.6/generic/tclIOCmd.c b/tcl8.6/generic/tclIOCmd.c
new file mode 100644
index 0000000..834f225
--- /dev/null
+++ b/tcl8.6/generic/tclIOCmd.c
@@ -0,0 +1,2027 @@
+/*
+ * tclIOCmd.c --
+ *
+ *	Contains the definitions of most of the Tcl commands relating to IO.
+ *
+ * Copyright (c) 1995-1997 Sun Microsystems, Inc.
+ *
+ * See the file "license.terms" for information on usage and redistribution of
+ * this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ */
+
+#include "tclInt.h"
+
+/*
+ * Callback structure for accept callback in a TCP server.
+ */
+
+typedef struct AcceptCallback {
+    char *script;		/* Script to invoke. */
+    Tcl_Interp *interp;		/* Interpreter in which to run it. */
+} AcceptCallback;
+
+/*
+ * Thread local storage used to maintain a per-thread stdout channel obj.
+ * It must be per-thread because of std channel limitations.
+ */
+
+typedef struct ThreadSpecificData {
+    int initialized;		/* Set to 1 when the module is initialized. */
+    Tcl_Obj *stdoutObjPtr;	/* Cached stdout channel Tcl_Obj */
+} ThreadSpecificData;
+
+static Tcl_ThreadDataKey dataKey;
+
+/*
+ * Static functions for this file:
+ */
+
+static void		FinalizeIOCmdTSD(ClientData clientData);
+static void		AcceptCallbackProc(ClientData callbackData,
+			    Tcl_Channel chan, char *address, int port);
+static int		ChanPendingObjCmd(ClientData unused,
+			    Tcl_Interp *interp, int objc,
+			    Tcl_Obj *const objv[]);
+static int		ChanTruncateObjCmd(ClientData dummy,
+			    Tcl_Interp *interp, int objc,
+			    Tcl_Obj *const objv[]);
+static void		RegisterTcpServerInterpCleanup(Tcl_Interp *interp,
+			    AcceptCallback *acceptCallbackPtr);
+static void		TcpAcceptCallbacksDeleteProc(ClientData clientData,
+			    Tcl_Interp *interp);
+static void		TcpServerCloseProc(ClientData callbackData);
+static void		UnregisterTcpServerInterpCleanupProc(
+			    Tcl_Interp *interp,
+			    AcceptCallback *acceptCallbackPtr);
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * FinalizeIOCmdTSD --
+ *
+ *	Release the storage associated with the per-thread cache.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+FinalizeIOCmdTSD(
+    ClientData clientData)	/* Not used. */
+{
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+
+    if (tsdPtr->stdoutObjPtr != NULL) {
+	Tcl_DecrRefCount(tsdPtr->stdoutObjPtr);
+	tsdPtr->stdoutObjPtr = NULL;
+    }
+    tsdPtr->initialized = 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_PutsObjCmd --
+ *
+ *	This function is invoked to process the "puts" Tcl command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Produces output on a channel.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_PutsObjCmd(
+    ClientData dummy,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;		/* The channel to puts on. */
+    Tcl_Obj *string;		/* String to write. */
+    Tcl_Obj *chanObjPtr = NULL;	/* channel object. */
+    int newline;		/* Add a newline at end? */
+    int result;			/* Result of puts operation. */
+    int mode;			/* Mode in which channel is opened. */
+    ThreadSpecificData *tsdPtr;
+
+    switch (objc) {
+    case 2:			/* [puts $x] */
+	string = objv[1];
+	newline = 1;
+	break;
+
+    case 3:			/* [puts -nonewline $x] or [puts $chan $x] */
+	if (strcmp(TclGetString(objv[1]), "-nonewline") == 0) {
+	    newline = 0;
+	} else {
+	    newline = 1;
+	    chanObjPtr = objv[1];
+	}
+	string = objv[2];
+	break;
+
+    case 4:			/* [puts -nonewline $chan $x] or
+				 * [puts $chan $x nonewline] */
+	newline = 0;
+	if (strcmp(TclGetString(objv[1]), "-nonewline") == 0) {
+	    chanObjPtr = objv[2];
+	    string = objv[3];
+	    break;
+#if TCL_MAJOR_VERSION < 9
+	} else if (strcmp(TclGetString(objv[3]), "nonewline") == 0) {
+	    /*
+	     * The code below provides backwards compatibility with an old
+	     * form of the command that is no longer recommended or
+	     * documented. See also [Bug #3151675]. Will be removed in Tcl 9,
+	     * maybe even earlier.
+	     */
+
+	    chanObjPtr = objv[1];
+	    string = objv[2];
+	    break;
+#endif
+	}
+	/* Fall through */
+    default:			/* [puts] or
+				 * [puts some bad number of arguments...] */
+	Tcl_WrongNumArgs(interp, 1, objv, "?-nonewline? ?channelId? string");
+	return TCL_ERROR;
+    }
+
+    if (chanObjPtr == NULL) {
+	tsdPtr = TCL_TSD_INIT(&dataKey);
+
+	if (!tsdPtr->initialized) {
+	    tsdPtr->initialized = 1;
+	    TclNewLiteralStringObj(tsdPtr->stdoutObjPtr, "stdout");
+	    Tcl_IncrRefCount(tsdPtr->stdoutObjPtr);
+	    Tcl_CreateThreadExitHandler(FinalizeIOCmdTSD, NULL);
+	}
+	chanObjPtr = tsdPtr->stdoutObjPtr;
+    }
+    if (TclGetChannelFromObj(interp, chanObjPtr, &chan, &mode, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    if (!(mode & TCL_WRITABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for writing",
+		TclGetString(chanObjPtr)));
+	return TCL_ERROR;
+    }
+
+    TclChannelPreserve(chan);
+    result = Tcl_WriteObj(chan, string);
+    if (result < 0) {
+	goto error;
+    }
+    if (newline != 0) {
+	result = Tcl_WriteChars(chan, "\n", 1);
+	if (result < 0) {
+	    goto error;
+	}
+    }
+    TclChannelRelease(chan);
+    return TCL_OK;
+
+    /*
+     * TIP #219.
+     * Capture error messages put by the driver into the bypass area and put
+     * them into the regular interpreter result. Fall back to the regular
+     * message if nothing was found in the bypass.
+     */
+
+  error:
+    if (!TclChanCaughtErrorBypass(interp, chan)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf("error writing \"%s\": %s",
+		TclGetString(chanObjPtr), Tcl_PosixError(interp)));
+    }
+    TclChannelRelease(chan);
+    return TCL_ERROR;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_FlushObjCmd --
+ *
+ *	This function is called to process the Tcl "flush" command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	May cause output to appear on the specified channel.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_FlushObjCmd(
+    ClientData dummy,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Obj *chanObjPtr;
+    Tcl_Channel chan;		/* The channel to flush on. */
+    int mode;
+
+    if (objc != 2) {
+	Tcl_WrongNumArgs(interp, 1, objv, "channelId");
+	return TCL_ERROR;
+    }
+    chanObjPtr = objv[1];
+    if (TclGetChannelFromObj(interp, chanObjPtr, &chan, &mode, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    if (!(mode & TCL_WRITABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for writing",
+		TclGetString(chanObjPtr)));
+	return TCL_ERROR;
+    }
+
+    TclChannelPreserve(chan);
+    if (Tcl_Flush(chan) != TCL_OK) {
+	/*
+	 * TIP #219.
+	 * Capture error messages put by the driver into the bypass area and
+	 * put them into the regular interpreter result. Fall back to the
+	 * regular message if nothing was found in the bypass.
+	 */
+
+	if (!TclChanCaughtErrorBypass(interp, chan)) {
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error flushing \"%s\": %s",
+		    TclGetString(chanObjPtr), Tcl_PosixError(interp)));
+	}
+	TclChannelRelease(chan);
+	return TCL_ERROR;
+    }
+    TclChannelRelease(chan);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_GetsObjCmd --
+ *
+ *	This function is called to process the Tcl "gets" command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	May consume input from channel.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_GetsObjCmd(
+    ClientData dummy,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;		/* The channel to read from. */
+    int lineLen;		/* Length of line just read. */
+    int mode;			/* Mode in which channel is opened. */
+    Tcl_Obj *linePtr, *chanObjPtr;
+    int code = TCL_OK;
+
+    if ((objc != 2) && (objc != 3)) {
+	Tcl_WrongNumArgs(interp, 1, objv, "channelId ?varName?");
+	return TCL_ERROR;
+    }
+    chanObjPtr = objv[1];
+    if (TclGetChannelFromObj(interp, chanObjPtr, &chan, &mode, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    if (!(mode & TCL_READABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for reading",
+		TclGetString(chanObjPtr)));
+	return TCL_ERROR;
+    }
+
+    TclChannelPreserve(chan);
+    linePtr = Tcl_NewObj();
+    lineLen = Tcl_GetsObj(chan, linePtr);
+    if (lineLen < 0) {
+	if (!Tcl_Eof(chan) && !Tcl_InputBlocked(chan)) {
+	    Tcl_DecrRefCount(linePtr);
+
+	    /*
+	     * TIP #219.
+	     * Capture error messages put by the driver into the bypass area
+	     * and put them into the regular interpreter result. Fall back to
+	     * the regular message if nothing was found in the bypass.
+	     */
+
+	    if (!TclChanCaughtErrorBypass(interp, chan)) {
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"error reading \"%s\": %s",
+			TclGetString(chanObjPtr), Tcl_PosixError(interp)));
+	    }
+	    code = TCL_ERROR;
+	    goto done;
+	}
+	lineLen = -1;
+    }
+    if (objc == 3) {
+	if (Tcl_ObjSetVar2(interp, objv[2], NULL, linePtr,
+		TCL_LEAVE_ERR_MSG) == NULL) {
+	    code = TCL_ERROR;
+	    goto done;
+	}
+	Tcl_SetObjResult(interp, Tcl_NewIntObj(lineLen));
+    } else {
+	Tcl_SetObjResult(interp, linePtr);
+    }
+  done:
+    TclChannelRelease(chan);
+    return code;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ReadObjCmd --
+ *
+ *	This function is invoked to process the Tcl "read" command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	May consume input from channel.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_ReadObjCmd(
+    ClientData dummy,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;		/* The channel to read from. */
+    int newline, i;		/* Discard newline at end? */
+    int toRead;			/* How many bytes to read? */
+    int charactersRead;		/* How many characters were read? */
+    int mode;			/* Mode in which channel is opened. */
+    Tcl_Obj *resultPtr, *chanObjPtr;
+
+    if ((objc != 2) && (objc != 3)) {
+	Interp *iPtr;
+
+    argerror:
+	iPtr = (Interp *) interp;
+	Tcl_WrongNumArgs(interp, 1, objv, "channelId ?numChars?");
+
+	/*
+	 * Do not append directly; that makes ensembles using this command as
+	 * a subcommand produce the wrong message.
+	 */
+
+	iPtr->flags |= INTERP_ALTERNATE_WRONG_ARGS;
+	Tcl_WrongNumArgs(interp, 1, objv, "?-nonewline? channelId");
+	return TCL_ERROR;
+    }
+
+    i = 1;
+    newline = 0;
+    if (strcmp(TclGetString(objv[1]), "-nonewline") == 0) {
+	newline = 1;
+	i++;
+    }
+
+    if (i == objc) {
+	goto argerror;
+    }
+
+    chanObjPtr = objv[i];
+    if (TclGetChannelFromObj(interp, chanObjPtr, &chan, &mode, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    if (!(mode & TCL_READABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for reading",
+		TclGetString(chanObjPtr)));
+	return TCL_ERROR;
+    }
+    i++;			/* Consumed channel name. */
+
+    /*
+     * Compute how many bytes to read.
+     */
+
+    toRead = -1;
+    if (i < objc) {
+	if ((TclGetIntFromObj(interp, objv[i], &toRead) != TCL_OK)
+		|| (toRead < 0)) {
+#if TCL_MAJOR_VERSION < 9
+	    /*
+	     * The code below provides backwards compatibility with an old
+	     * form of the command that is no longer recommended or
+	     * documented. See also [Bug #3151675]. Will be removed in Tcl 9,
+	     * maybe even earlier.
+	     */
+
+	    if (strcmp(TclGetString(objv[i]), "nonewline") != 0) {
+#endif
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"expected non-negative integer but got \"%s\"",
+			TclGetString(objv[i])));
+		Tcl_SetErrorCode(interp, "TCL", "VALUE", "NUMBER", NULL);
+		return TCL_ERROR;
+#if TCL_MAJOR_VERSION < 9
+	    }
+	    newline = 1;
+#endif
+	}
+    }
+
+    resultPtr = Tcl_NewObj();
+    Tcl_IncrRefCount(resultPtr);
+    TclChannelPreserve(chan);
+    charactersRead = Tcl_ReadChars(chan, resultPtr, toRead, 0);
+    if (charactersRead < 0) {
+	/*
+	 * TIP #219.
+	 * Capture error messages put by the driver into the bypass area and
+	 * put them into the regular interpreter result. Fall back to the
+	 * regular message if nothing was found in the bypass.
+	 */
+
+	if (!TclChanCaughtErrorBypass(interp, chan)) {
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error reading \"%s\": %s",
+		    TclGetString(chanObjPtr), Tcl_PosixError(interp)));
+	}
+	TclChannelRelease(chan);
+	Tcl_DecrRefCount(resultPtr);
+	return TCL_ERROR;
+    }
+
+    /*
+     * If requested, remove the last newline in the channel if at EOF.
+     */
+
+    if ((charactersRead > 0) && (newline != 0)) {
+	const char *result;
+	int length;
+
+	result = TclGetStringFromObj(resultPtr, &length);
+	if (result[length - 1] == '\n') {
+	    Tcl_SetObjLength(resultPtr, length - 1);
+	}
+    }
+    Tcl_SetObjResult(interp, resultPtr);
+    TclChannelRelease(chan);
+    Tcl_DecrRefCount(resultPtr);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_SeekObjCmd --
+ *
+ *	This function is invoked to process the Tcl "seek" command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Moves the position of the access point on the specified channel.  May
+ *	flush queued output.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_SeekObjCmd(
+    ClientData clientData,	/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;		/* The channel to tell on. */
+    Tcl_WideInt offset;		/* Where to seek? */
+    int mode;			/* How to seek? */
+    Tcl_WideInt result;		/* Of calling Tcl_Seek. */
+    int optionIndex;
+    static const char *const originOptions[] = {
+	"start", "current", "end", NULL
+    };
+    static const int modeArray[] = {SEEK_SET, SEEK_CUR, SEEK_END};
+
+    if ((objc != 3) && (objc != 4)) {
+	Tcl_WrongNumArgs(interp, 1, objv, "channelId offset ?origin?");
+	return TCL_ERROR;
+    }
+    if (TclGetChannelFromObj(interp, objv[1], &chan, NULL, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    if (Tcl_GetWideIntFromObj(interp, objv[2], &offset) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    mode = SEEK_SET;
+    if (objc == 4) {
+	if (Tcl_GetIndexFromObj(interp, objv[3], originOptions, "origin", 0,
+		&optionIndex) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	mode = modeArray[optionIndex];
+    }
+
+    TclChannelPreserve(chan);
+    result = Tcl_Seek(chan, offset, mode);
+    if (result == Tcl_LongAsWide(-1)) {
+	/*
+	 * TIP #219.
+	 * Capture error messages put by the driver into the bypass area and
+	 * put them into the regular interpreter result. Fall back to the
+	 * regular message if nothing was found in the bypass.
+	 */
+
+	if (!TclChanCaughtErrorBypass(interp, chan)) {
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "error during seek on \"%s\": %s",
+		    TclGetString(objv[1]), Tcl_PosixError(interp)));
+	}
+	TclChannelRelease(chan);
+	return TCL_ERROR;
+    }
+    TclChannelRelease(chan);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_TellObjCmd --
+ *
+ *	This function is invoked to process the Tcl "tell" command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_TellObjCmd(
+    ClientData clientData,	/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;		/* The channel to tell on. */
+    Tcl_WideInt newLoc;
+    int code;
+
+    if (objc != 2) {
+	Tcl_WrongNumArgs(interp, 1, objv, "channelId");
+	return TCL_ERROR;
+    }
+
+    /*
+     * Try to find a channel with the right name and permissions in the IO
+     * channel table of this interpreter.
+     */
+
+    if (TclGetChannelFromObj(interp, objv[1], &chan, NULL, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    TclChannelPreserve(chan);
+    newLoc = Tcl_Tell(chan);
+
+    /*
+     * TIP #219.
+     * Capture error messages put by the driver into the bypass area and put
+     * them into the regular interpreter result.
+     */
+
+
+    code  = TclChanCaughtErrorBypass(interp, chan);
+    TclChannelRelease(chan);
+    if (code) {
+	return TCL_ERROR;
+    }
+
+    Tcl_SetObjResult(interp, Tcl_NewWideIntObj(newLoc));
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_CloseObjCmd --
+ *
+ *	This function is invoked to process the Tcl "close" command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	May discard queued input; may flush queued output.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_CloseObjCmd(
+    ClientData clientData,	/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;		/* The channel to close. */
+    static const char *const dirOptions[] = {
+	"read", "write", NULL
+    };
+    static const int dirArray[] = {TCL_CLOSE_READ, TCL_CLOSE_WRITE};
+
+    if ((objc != 2) && (objc != 3)) {
+	Tcl_WrongNumArgs(interp, 1, objv, "channelId ?direction?");
+	return TCL_ERROR;
+    }
+
+    if (TclGetChannelFromObj(interp, objv[1], &chan, NULL, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    if (objc == 3) {
+	int index, dir;
+
+	/*
+	 * Get direction requested to close, and check syntax.
+	 */
+
+	if (Tcl_GetIndexFromObj(interp, objv[2], dirOptions, "direction", 0,
+		&index) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	dir = dirArray[index];
+
+	/*
+	 * Check direction against channel mode. It is an error if we try to
+	 * close a direction not supported by the channel (already closed, or
+	 * never opened for that direction).
+	 */
+
+	if (!(dir & Tcl_GetChannelMode(chan))) {
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "Half-close of %s-side not possible, side not opened"
+		    " or already closed", dirOptions[index]));
+	    return TCL_ERROR;
+	}
+
+	/*
+	 * Special handling is needed if and only if the channel mode supports
+	 * more than the direction to close. Because if the close the last
+	 * direction suppported we can and will go through the regular
+	 * process.
+	 */
+
+	if ((Tcl_GetChannelMode(chan) &
+		(TCL_CLOSE_READ|TCL_CLOSE_WRITE)) != dir) {
+	    return Tcl_CloseEx(interp, chan, dir);
+	}
+    }
+
+    if (Tcl_UnregisterChannel(interp, chan) != TCL_OK) {
+	/*
+	 * If there is an error message and it ends with a newline, remove the
+	 * newline. This is done for command pipeline channels where the error
+	 * output from the subprocesses is stored in interp's result.
+	 *
+	 * NOTE: This is likely to not have any effect on regular error
+	 * messages produced by drivers during the closing of a channel,
+	 * because the Tcl convention is that such error messages do not have
+	 * a terminating newline.
+	 */
+
+	Tcl_Obj *resultPtr = Tcl_GetObjResult(interp);
+	const char *string;
+	int len;
+
+	if (Tcl_IsShared(resultPtr)) {
+	    resultPtr = Tcl_DuplicateObj(resultPtr);
+	    Tcl_SetObjResult(interp, resultPtr);
+	}
+	string = TclGetStringFromObj(resultPtr, &len);
+	if ((len > 0) && (string[len - 1] == '\n')) {
+	    Tcl_SetObjLength(resultPtr, len - 1);
+	}
+	return TCL_ERROR;
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_FconfigureObjCmd --
+ *
+ *	This function is invoked to process the Tcl "fconfigure" command. See
+ *	the user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	May modify the behavior of an IO channel.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_FconfigureObjCmd(
+    ClientData clientData,	/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    const char *optionName, *valueName;
+    Tcl_Channel chan;		/* The channel to set a mode on. */
+    int i;			/* Iterate over arg-value pairs. */
+
+    if ((objc < 2) || (((objc % 2) == 1) && (objc != 3))) {
+	Tcl_WrongNumArgs(interp, 1, objv, "channelId ?-option value ...?");
+	return TCL_ERROR;
+    }
+
+    if (TclGetChannelFromObj(interp, objv[1], &chan, NULL, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    if (objc == 2) {
+	Tcl_DString ds;		/* DString to hold result of calling
+				 * Tcl_GetChannelOption. */
+
+	Tcl_DStringInit(&ds);
+	if (Tcl_GetChannelOption(interp, chan, NULL, &ds) != TCL_OK) {
+	    Tcl_DStringFree(&ds);
+	    return TCL_ERROR;
+	}
+	Tcl_DStringResult(interp, &ds);
+	return TCL_OK;
+    } else if (objc == 3) {
+	Tcl_DString ds;		/* DString to hold result of calling
+				 * Tcl_GetChannelOption. */
+
+	Tcl_DStringInit(&ds);
+	optionName = TclGetString(objv[2]);
+	if (Tcl_GetChannelOption(interp, chan, optionName, &ds) != TCL_OK) {
+	    Tcl_DStringFree(&ds);
+	    return TCL_ERROR;
+	}
+	Tcl_DStringResult(interp, &ds);
+	return TCL_OK;
+    }
+
+    for (i = 3; i < objc; i += 2) {
+	optionName = TclGetString(objv[i-1]);
+	valueName = TclGetString(objv[i]);
+	if (Tcl_SetChannelOption(interp, chan, optionName, valueName)
+		!= TCL_OK) {
+	    return TCL_ERROR;
+	}
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *---------------------------------------------------------------------------
+ *
+ * Tcl_EofObjCmd --
+ *
+ *	This function is invoked to process the Tcl "eof" command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Sets interp's result to boolean true or false depending on whether the
+ *	specified channel has an EOF condition.
+ *
+ *---------------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_EofObjCmd(
+    ClientData unused,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;
+
+    if (objc != 2) {
+	Tcl_WrongNumArgs(interp, 1, objv, "channelId");
+	return TCL_ERROR;
+    }
+
+    if (TclGetChannelFromObj(interp, objv[1], &chan, NULL, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(Tcl_Eof(chan)));
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ExecObjCmd --
+ *
+ *	This function is invoked to process the "exec" Tcl command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	See the user documentation.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_ExecObjCmd(
+    ClientData dummy,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Obj *resultPtr;
+    const char **argv;		/* An array for the string arguments. Stored
+				 * on the _Tcl_ stack. */
+    const char *string;
+    Tcl_Channel chan;
+    int argc, background, i, index, keepNewline, result, skip, length;
+    int ignoreStderr;
+    static const char *const options[] = {
+	"-ignorestderr", "-keepnewline", "--", NULL
+    };
+    enum options {
+	EXEC_IGNORESTDERR, EXEC_KEEPNEWLINE, EXEC_LAST
+    };
+
+    /*
+     * Check for any leading option arguments.
+     */
+
+    keepNewline = 0;
+    ignoreStderr = 0;
+    for (skip = 1; skip < objc; skip++) {
+	string = TclGetString(objv[skip]);
+	if (string[0] != '-') {
+	    break;
+	}
+	if (Tcl_GetIndexFromObj(interp, objv[skip], options, "option",
+		TCL_EXACT, &index) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	if (index == EXEC_KEEPNEWLINE) {
+	    keepNewline = 1;
+	} else if (index == EXEC_IGNORESTDERR) {
+	    ignoreStderr = 1;
+	} else {
+	    skip++;
+	    break;
+	}
+    }
+    if (objc <= skip) {
+	Tcl_WrongNumArgs(interp, 1, objv, "?-option ...? arg ?arg ...?");
+	return TCL_ERROR;
+    }
+
+    /*
+     * See if the command is to be run in background.
+     */
+
+    background = 0;
+    string = TclGetString(objv[objc - 1]);
+    if ((string[0] == '&') && (string[1] == '\0')) {
+	objc--;
+	background = 1;
+    }
+
+    /*
+     * Create the string argument array "argv". Make sure argv is large enough
+     * to hold the argc arguments plus 1 extra for the zero end-of-argv word.
+     */
+
+    argc = objc - skip;
+    argv = TclStackAlloc(interp, (unsigned)(argc + 1) * sizeof(char *));
+
+    /*
+     * Copy the string conversions of each (post option) object into the
+     * argument vector.
+     */
+
+    for (i = 0; i < argc; i++) {
+	argv[i] = TclGetString(objv[i + skip]);
+    }
+    argv[argc] = NULL;
+    chan = Tcl_OpenCommandChannel(interp, argc, argv, (background ? 0 :
+	    ignoreStderr ? TCL_STDOUT : TCL_STDOUT|TCL_STDERR));
+
+    /*
+     * Free the argv array.
+     */
+
+    TclStackFree(interp, (void *) argv);
+
+    if (chan == NULL) {
+	return TCL_ERROR;
+    }
+
+    if (background) {
+	/*
+	 * Store the list of PIDs from the pipeline in interp's result and
+	 * detach the PIDs (instead of waiting for them).
+	 */
+
+	TclGetAndDetachPids(interp, chan);
+	if (Tcl_Close(interp, chan) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	return TCL_OK;
+    }
+
+    resultPtr = Tcl_NewObj();
+    if (Tcl_GetChannelHandle(chan, TCL_READABLE, NULL) == TCL_OK) {
+	if (Tcl_ReadChars(chan, resultPtr, -1, 0) < 0) {
+	    /*
+	     * TIP #219.
+	     * Capture error messages put by the driver into the bypass area
+	     * and put them into the regular interpreter result. Fall back to
+	     * the regular message if nothing was found in the bypass.
+	     */
+
+	    if (!TclChanCaughtErrorBypass(interp, chan)) {
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"error reading output from command: %s",
+			Tcl_PosixError(interp)));
+		Tcl_DecrRefCount(resultPtr);
+	    }
+	    return TCL_ERROR;
+	}
+    }
+
+    /*
+     * If the process produced anything on stderr, it will have been returned
+     * in the interpreter result. It needs to be appended to the result
+     * string.
+     */
+
+    result = Tcl_Close(interp, chan);
+    Tcl_AppendObjToObj(resultPtr, Tcl_GetObjResult(interp));
+
+    /*
+     * If the last character of the result is a newline, then remove the
+     * newline character.
+     */
+
+    if (keepNewline == 0) {
+	string = TclGetStringFromObj(resultPtr, &length);
+	if ((length > 0) && (string[length - 1] == '\n')) {
+	    Tcl_SetObjLength(resultPtr, length - 1);
+	}
+    }
+    Tcl_SetObjResult(interp, resultPtr);
+
+    return result;
+}
+
+/*
+ *---------------------------------------------------------------------------
+ *
+ * Tcl_FblockedObjCmd --
+ *
+ *	This function is invoked to process the Tcl "fblocked" command. See
+ *	the user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Sets interp's result to boolean true or false depending on whether the
+ *	preceeding input operation on the channel would have blocked.
+ *
+ *---------------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_FblockedObjCmd(
+    ClientData unused,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;
+    int mode;
+
+    if (objc != 2) {
+	Tcl_WrongNumArgs(interp, 1, objv, "channelId");
+	return TCL_ERROR;
+    }
+
+    if (TclGetChannelFromObj(interp, objv[1], &chan, &mode, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    if (!(mode & TCL_READABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for reading",
+		TclGetString(objv[1])));
+	return TCL_ERROR;
+    }
+
+    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(Tcl_InputBlocked(chan)));
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_OpenObjCmd --
+ *
+ *	This function is invoked to process the "open" Tcl command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	See the user documentation.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+Tcl_OpenObjCmd(
+    ClientData notUsed,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    int pipeline, prot;
+    const char *modeString, *what;
+    Tcl_Channel chan;
+
+    if ((objc < 2) || (objc > 4)) {
+	Tcl_WrongNumArgs(interp, 1, objv, "fileName ?access? ?permissions?");
+	return TCL_ERROR;
+    }
+    prot = 0666;
+    if (objc == 2) {
+	modeString = "r";
+    } else {
+	modeString = TclGetString(objv[2]);
+	if (objc == 4) {
+	    const char *permString = TclGetString(objv[3]);
+	    int code = TCL_ERROR;
+	    int scanned = TclParseAllWhiteSpace(permString, -1);
+
+	    /*
+	     * Support legacy octal numbers.
+	     */
+
+	    if ((permString[scanned] == '0')
+		    && (permString[scanned+1] >= '0')
+		    && (permString[scanned+1] <= '7')) {
+		Tcl_Obj *permObj;
+
+		TclNewLiteralStringObj(permObj, "0o");
+		Tcl_AppendToObj(permObj, permString+scanned+1, -1);
+		code = TclGetIntFromObj(NULL, permObj, &prot);
+		Tcl_DecrRefCount(permObj);
+	    }
+
+	    if ((code == TCL_ERROR)
+		    && TclGetIntFromObj(interp, objv[3], &prot) != TCL_OK) {
+		return TCL_ERROR;
+	    }
+	}
+    }
+
+    pipeline = 0;
+    what = TclGetString(objv[1]);
+    if (what[0] == '|') {
+	pipeline = 1;
+    }
+
+    /*
+     * Open the file or create a process pipeline.
+     */
+
+    if (!pipeline) {
+	chan = Tcl_FSOpenFileChannel(interp, objv[1], modeString, prot);
+    } else {
+	int mode, seekFlag, cmdObjc, binary;
+	const char **cmdArgv;
+
+	if (Tcl_SplitList(interp, what+1, &cmdObjc, &cmdArgv) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+
+	mode = TclGetOpenModeEx(interp, modeString, &seekFlag, &binary);
+	if (mode == -1) {
+	    chan = NULL;
+	} else {
+	    int flags = TCL_STDERR | TCL_ENFORCE_MODE;
+
+	    switch (mode & (O_RDONLY | O_WRONLY | O_RDWR)) {
+	    case O_RDONLY:
+		flags |= TCL_STDOUT;
+		break;
+	    case O_WRONLY:
+		flags |= TCL_STDIN;
+		break;
+	    case O_RDWR:
+		flags |= (TCL_STDIN | TCL_STDOUT);
+		break;
+	    default:
+		Tcl_Panic("Tcl_OpenCmd: invalid mode value");
+		break;
+	    }
+	    chan = Tcl_OpenCommandChannel(interp, cmdObjc, cmdArgv, flags);
+	    if (binary && chan) {
+		Tcl_SetChannelOption(interp, chan, "-translation", "binary");
+	    }
+	}
+	ckfree(cmdArgv);
+    }
+    if (chan == NULL) {
+	return TCL_ERROR;
+    }
+    Tcl_RegisterChannel(interp, chan);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(Tcl_GetChannelName(chan), -1));
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TcpAcceptCallbacksDeleteProc --
+ *
+ *	Assocdata cleanup routine called when an interpreter is being deleted
+ *	to set the interp field of all the accept callback records registered
+ *	with the interpreter to NULL. This will prevent the interpreter from
+ *	being used in the future to eval accept scripts.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Deallocates memory and sets the interp field of all the accept
+ *	callback records to NULL to prevent this interpreter from being used
+ *	subsequently to eval accept scripts.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static void
+TcpAcceptCallbacksDeleteProc(
+    ClientData clientData,	/* Data which was passed when the assocdata
+				 * was registered. */
+    Tcl_Interp *interp)		/* Interpreter being deleted - not used. */
+{
+    Tcl_HashTable *hTblPtr = clientData;
+    Tcl_HashEntry *hPtr;
+    Tcl_HashSearch hSearch;
+
+    for (hPtr = Tcl_FirstHashEntry(hTblPtr, &hSearch);
+	    hPtr != NULL; hPtr = Tcl_NextHashEntry(&hSearch)) {
+	AcceptCallback *acceptCallbackPtr = Tcl_GetHashValue(hPtr);
+
+	acceptCallbackPtr->interp = NULL;
+    }
+    Tcl_DeleteHashTable(hTblPtr);
+    ckfree(hTblPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * RegisterTcpServerInterpCleanup --
+ *
+ *	Registers an accept callback record to have its interp field set to
+ *	NULL when the interpreter is deleted.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	When, in the future, the interpreter is deleted, the interp field of
+ *	the accept callback data structure will be set to NULL. This will
+ *	prevent attempts to eval the accept script in a deleted interpreter.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+RegisterTcpServerInterpCleanup(
+    Tcl_Interp *interp,		/* Interpreter for which we want to be
+				 * informed of deletion. */
+    AcceptCallback *acceptCallbackPtr)
+				/* The accept callback record whose interp
+				 * field we want set to NULL when the
+				 * interpreter is deleted. */
+{
+    Tcl_HashTable *hTblPtr;	/* Hash table for accept callback records to
+				 * smash when the interpreter will be
+				 * deleted. */
+    Tcl_HashEntry *hPtr;	/* Entry for this record. */
+    int isNew;			/* Is the entry new? */
+
+    hTblPtr = Tcl_GetAssocData(interp, "tclTCPAcceptCallbacks", NULL);
+
+    if (hTblPtr == NULL) {
+	hTblPtr = ckalloc(sizeof(Tcl_HashTable));
+	Tcl_InitHashTable(hTblPtr, TCL_ONE_WORD_KEYS);
+	Tcl_SetAssocData(interp, "tclTCPAcceptCallbacks",
+		TcpAcceptCallbacksDeleteProc, hTblPtr);
+    }
+
+    hPtr = Tcl_CreateHashEntry(hTblPtr, acceptCallbackPtr, &isNew);
+    if (!isNew) {
+	Tcl_Panic("RegisterTcpServerCleanup: damaged accept record table");
+    }
+    Tcl_SetHashValue(hPtr, acceptCallbackPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * UnregisterTcpServerInterpCleanupProc --
+ *
+ *	Unregister a previously registered accept callback record. The interp
+ *	field of this record will no longer be set to NULL in the future when
+ *	the interpreter is deleted.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Prevents the interp field of the accept callback record from being set
+ *	to NULL in the future when the interpreter is deleted.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+UnregisterTcpServerInterpCleanupProc(
+    Tcl_Interp *interp,		/* Interpreter in which the accept callback
+				 * record was registered. */
+    AcceptCallback *acceptCallbackPtr)
+				/* The record for which to delete the
+				 * registration. */
+{
+    Tcl_HashTable *hTblPtr;
+    Tcl_HashEntry *hPtr;
+
+    hTblPtr = Tcl_GetAssocData(interp, "tclTCPAcceptCallbacks", NULL);
+    if (hTblPtr == NULL) {
+	return;
+    }
+
+    hPtr = Tcl_FindHashEntry(hTblPtr, (char *) acceptCallbackPtr);
+    if (hPtr != NULL) {
+	Tcl_DeleteHashEntry(hPtr);
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * AcceptCallbackProc --
+ *
+ *	This callback is invoked by the TCP channel driver when it accepts a
+ *	new connection from a client on a server socket.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Whatever the script does.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+AcceptCallbackProc(
+    ClientData callbackData,	/* The data stored when the callback was
+				 * created in the call to
+				 * Tcl_OpenTcpServer. */
+    Tcl_Channel chan,		/* Channel for the newly accepted
+				 * connection. */
+    char *address,		/* Address of client that was accepted. */
+    int port)			/* Port of client that was accepted. */
+{
+    AcceptCallback *acceptCallbackPtr = callbackData;
+
+    /*
+     * Check if the callback is still valid; the interpreter may have gone
+     * away, this is signalled by setting the interp field of the callback
+     * data to NULL.
+     */
+
+    if (acceptCallbackPtr->interp != NULL) {
+	char portBuf[TCL_INTEGER_SPACE];
+	char *script = acceptCallbackPtr->script;
+	Tcl_Interp *interp = acceptCallbackPtr->interp;
+	int result;
+
+	Tcl_Preserve(script);
+	Tcl_Preserve(interp);
+
+	TclFormatInt(portBuf, port);
+	Tcl_RegisterChannel(interp, chan);
+
+	/*
+	 * Artificially bump the refcount to protect the channel from being
+	 * deleted while the script is being evaluated.
+	 */
+
+	Tcl_RegisterChannel(NULL, chan);
+
+	result = Tcl_VarEval(interp, script, " ", Tcl_GetChannelName(chan),
+		" ", address, " ", portBuf, NULL);
+	if (result != TCL_OK) {
+	    Tcl_BackgroundException(interp, result);
+	    Tcl_UnregisterChannel(interp, chan);
+	}
+
+	/*
+	 * Decrement the artificially bumped refcount. After this it is not
+	 * safe anymore to use "chan", because it may now be deleted.
+	 */
+
+	Tcl_UnregisterChannel(NULL, chan);
+
+	Tcl_Release(interp);
+	Tcl_Release(script);
+    } else {
+	/*
+	 * The interpreter has been deleted, so there is no useful way to use
+	 * the client socket - just close it.
+	 */
+
+	Tcl_Close(NULL, chan);
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TcpServerCloseProc --
+ *
+ *	This callback is called when the TCP server channel for which it was
+ *	registered is being closed. It informs the interpreter in which the
+ *	accept script is evaluated (if that interpreter still exists) that
+ *	this channel no longer needs to be informed if the interpreter is
+ *	deleted.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	In the future, if the interpreter is deleted this channel will no
+ *	longer be informed.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+TcpServerCloseProc(
+    ClientData callbackData)	/* The data passed in the call to
+				 * Tcl_CreateCloseHandler. */
+{
+    AcceptCallback *acceptCallbackPtr = callbackData;
+				/* The actual data. */
+
+    if (acceptCallbackPtr->interp != NULL) {
+	UnregisterTcpServerInterpCleanupProc(acceptCallbackPtr->interp,
+		acceptCallbackPtr);
+    }
+    Tcl_EventuallyFree(acceptCallbackPtr->script, TCL_DYNAMIC);
+    ckfree(acceptCallbackPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_SocketObjCmd --
+ *
+ *	This function is invoked to process the "socket" Tcl command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Creates a socket based channel.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_SocketObjCmd(
+    ClientData notUsed,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    static const char *const socketOptions[] = {
+	"-async", "-myaddr", "-myport", "-server", NULL
+    };
+    enum socketOptions {
+	SKT_ASYNC, SKT_MYADDR, SKT_MYPORT, SKT_SERVER
+    };
+    int optionIndex, a, server = 0, port, myport = 0, async = 0;
+    const char *host, *script = NULL, *myaddr = NULL;
+    Tcl_Channel chan;
+
+    if (TclpHasSockets(interp) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    for (a = 1; a < objc; a++) {
+	const char *arg = Tcl_GetString(objv[a]);
+
+	if (arg[0] != '-') {
+	    break;
+	}
+	if (Tcl_GetIndexFromObj(interp, objv[a], socketOptions, "option",
+		TCL_EXACT, &optionIndex) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	switch ((enum socketOptions) optionIndex) {
+	case SKT_ASYNC:
+	    if (server == 1) {
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"cannot set -async option for server sockets", -1));
+		return TCL_ERROR;
+	    }
+	    async = 1;
+	    break;
+	case SKT_MYADDR:
+	    a++;
+	    if (a >= objc) {
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"no argument given for -myaddr option", -1));
+		return TCL_ERROR;
+	    }
+	    myaddr = TclGetString(objv[a]);
+	    break;
+	case SKT_MYPORT: {
+	    const char *myPortName;
+
+	    a++;
+	    if (a >= objc) {
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"no argument given for -myport option", -1));
+		return TCL_ERROR;
+	    }
+	    myPortName = TclGetString(objv[a]);
+	    if (TclSockGetPort(interp, myPortName, "tcp", &myport) != TCL_OK) {
+		return TCL_ERROR;
+	    }
+	    break;
+	}
+	case SKT_SERVER:
+	    if (async == 1) {
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"cannot set -async option for server sockets", -1));
+		return TCL_ERROR;
+	    }
+	    server = 1;
+	    a++;
+	    if (a >= objc) {
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(
+			"no argument given for -server option", -1));
+		return TCL_ERROR;
+	    }
+	    script = TclGetString(objv[a]);
+	    break;
+	default:
+	    Tcl_Panic("Tcl_SocketObjCmd: bad option index to SocketOptions");
+	}
+    }
+    if (server) {
+	host = myaddr;		/* NULL implies INADDR_ANY */
+	if (myport != 0) {
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "option -myport is not valid for servers", -1));
+	    return TCL_ERROR;
+	}
+    } else if (a < objc) {
+	host = TclGetString(objv[a]);
+	a++;
+    } else {
+	Interp *iPtr;
+
+    wrongNumArgs:
+	iPtr = (Interp *) interp;
+	Tcl_WrongNumArgs(interp, 1, objv,
+		"?-myaddr addr? ?-myport myport? ?-async? host port");
+	iPtr->flags |= INTERP_ALTERNATE_WRONG_ARGS;
+	Tcl_WrongNumArgs(interp, 1, objv,
+		"-server command ?-myaddr addr? port");
+	return TCL_ERROR;
+    }
+
+    if (a == objc-1) {
+	if (TclSockGetPort(interp, TclGetString(objv[a]), "tcp",
+		&port) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+    } else {
+	goto wrongNumArgs;
+    }
+
+    if (server) {
+	AcceptCallback *acceptCallbackPtr =
+		ckalloc(sizeof(AcceptCallback));
+	unsigned len = strlen(script) + 1;
+	char *copyScript = ckalloc(len);
+
+	memcpy(copyScript, script, len);
+	acceptCallbackPtr->script = copyScript;
+	acceptCallbackPtr->interp = interp;
+	chan = Tcl_OpenTcpServer(interp, port, host, AcceptCallbackProc,
+		acceptCallbackPtr);
+	if (chan == NULL) {
+	    ckfree(copyScript);
+	    ckfree(acceptCallbackPtr);
+	    return TCL_ERROR;
+	}
+
+	/*
+	 * Register with the interpreter to let us know when the interpreter
+	 * is deleted (by having the callback set the interp field of the
+	 * acceptCallbackPtr's structure to NULL). This is to avoid trying to
+	 * eval the script in a deleted interpreter.
+	 */
+
+	RegisterTcpServerInterpCleanup(interp, acceptCallbackPtr);
+
+	/*
+	 * Register a close callback. This callback will inform the
+	 * interpreter (if it still exists) that this channel does not need to
+	 * be informed when the interpreter is deleted.
+	 */
+
+	Tcl_CreateCloseHandler(chan, TcpServerCloseProc, acceptCallbackPtr);
+    } else {
+	chan = Tcl_OpenTcpClient(interp, port, host, myaddr, myport, async);
+	if (chan == NULL) {
+	    return TCL_ERROR;
+	}
+    }
+
+    Tcl_RegisterChannel(interp, chan);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(Tcl_GetChannelName(chan), -1));
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_FcopyObjCmd --
+ *
+ *	This function is invoked to process the "fcopy" Tcl command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Moves data between two channels and possibly sets up a background copy
+ *	handler.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_FcopyObjCmd(
+    ClientData dummy,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel inChan, outChan;
+    int mode, i, index;
+    Tcl_WideInt toRead;
+    Tcl_Obj *cmdPtr;
+    static const char *const switches[] = { "-size", "-command", NULL };
+    enum { FcopySize, FcopyCommand };
+
+    if ((objc < 3) || (objc > 7) || (objc == 4) || (objc == 6)) {
+	Tcl_WrongNumArgs(interp, 1, objv,
+		"input output ?-size size? ?-command callback?");
+	return TCL_ERROR;
+    }
+
+    /*
+     * Parse the channel arguments and verify that they are readable or
+     * writable, as appropriate.
+     */
+
+    if (TclGetChannelFromObj(interp, objv[1], &inChan, &mode, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    if (!(mode & TCL_READABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for reading",
+		TclGetString(objv[1])));
+	return TCL_ERROR;
+    }
+    if (TclGetChannelFromObj(interp, objv[2], &outChan, &mode, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+    if (!(mode & TCL_WRITABLE)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"channel \"%s\" wasn't opened for writing",
+		TclGetString(objv[2])));
+	return TCL_ERROR;
+    }
+
+    toRead = -1;
+    cmdPtr = NULL;
+    for (i = 3; i < objc; i += 2) {
+	if (Tcl_GetIndexFromObj(interp, objv[i], switches, "option", 0,
+		&index) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	switch (index) {
+	case FcopySize:
+	    if (Tcl_GetWideIntFromObj(interp, objv[i+1], &toRead) != TCL_OK) {
+		return TCL_ERROR;
+	    }
+	    if (toRead < 0) {
+		/*
+		 * Handle all negative sizes like -1, meaning 'copy all'. By
+		 * resetting toRead we avoid changes in the core copying
+		 * functions (which explicitly check for -1 and crash on any
+		 * other negative value).
+		 */
+
+		toRead = -1;
+	    }
+	    break;
+	case FcopyCommand:
+	    cmdPtr = objv[i+1];
+	    break;
+	}
+    }
+
+    return TclCopyChannel(interp, inChan, outChan, toRead, cmdPtr);
+}
+
+/*
+ *---------------------------------------------------------------------------
+ *
+ * ChanPendingObjCmd --
+ *
+ *	This function is invoked to process the Tcl "chan pending" command
+ *	(TIP #287). See the user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Sets interp's result to the number of bytes of buffered input or
+ *	output (depending on whether the first argument is "input" or
+ *	"output"), or -1 if the channel wasn't opened for that mode.
+ *
+ *---------------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static int
+ChanPendingObjCmd(
+    ClientData unused,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;
+    int index, mode;
+    static const char *const options[] = {"input", "output", NULL};
+    enum options {PENDING_INPUT, PENDING_OUTPUT};
+
+    if (objc != 3) {
+	Tcl_WrongNumArgs(interp, 1, objv, "mode channelId");
+	return TCL_ERROR;
+    }
+
+    if (Tcl_GetIndexFromObj(interp, objv[1], options, "mode", 0,
+	    &index) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    if (TclGetChannelFromObj(interp, objv[2], &chan, &mode, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    switch ((enum options) index) {
+    case PENDING_INPUT:
+	if (!(mode & TCL_READABLE)) {
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(-1));
+	} else {
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(Tcl_InputBuffered(chan)));
+	}
+	break;
+    case PENDING_OUTPUT:
+	if (!(mode & TCL_WRITABLE)) {
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(-1));
+	} else {
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(Tcl_OutputBuffered(chan)));
+	}
+	break;
+    }
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ChanTruncateObjCmd --
+ *
+ *	This function is invoked to process the "chan truncate" Tcl command.
+ *	See the user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Truncates a channel (or rather a file underlying a channel).
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+ChanTruncateObjCmd(
+    ClientData dummy,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;
+    Tcl_WideInt length;
+
+    if ((objc < 2) || (objc > 3)) {
+	Tcl_WrongNumArgs(interp, 1, objv, "channelId ?length?");
+	return TCL_ERROR;
+    }
+    if (TclGetChannelFromObj(interp, objv[1], &chan, NULL, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    if (objc == 3) {
+	/*
+	 * User is supplying an explicit length.
+	 */
+
+	if (Tcl_GetWideIntFromObj(interp, objv[2], &length) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	if (length < 0) {
+	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		    "cannot truncate to negative length of file", -1));
+	    return TCL_ERROR;
+	}
+    } else {
+	/*
+	 * User wants to truncate to the current file position.
+	 */
+
+	length = Tcl_Tell(chan);
+	if (length == Tcl_WideAsLong(-1)) {
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "could not determine current location in \"%s\": %s",
+		    TclGetString(objv[1]), Tcl_PosixError(interp)));
+	    return TCL_ERROR;
+	}
+    }
+
+    if (Tcl_TruncateChannel(chan, length) != TCL_OK) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"error during truncate on \"%s\": %s",
+		TclGetString(objv[1]), Tcl_PosixError(interp)));
+	return TCL_ERROR;
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ChanPipeObjCmd --
+ *
+ *	This function is invoked to process the "chan pipe" Tcl command.
+ *	See the user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Creates a pair of Tcl channels wrapping both ends of a new
+ *	anonymous pipe.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+ChanPipeObjCmd(
+    ClientData dummy,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Tcl_Channel rchan, wchan;
+    const char *channelNames[2];
+    Tcl_Obj *resultPtr;
+
+    if (objc != 1) {
+	Tcl_WrongNumArgs(interp, 1, objv, "");
+	return TCL_ERROR;
+    }
+
+    if (Tcl_CreatePipe(interp, &rchan, &wchan, 0) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    channelNames[0] = Tcl_GetChannelName(rchan);
+    channelNames[1] = Tcl_GetChannelName(wchan);
+
+    resultPtr = Tcl_NewObj();
+    Tcl_ListObjAppendElement(NULL, resultPtr,
+	    Tcl_NewStringObj(channelNames[0], -1));
+    Tcl_ListObjAppendElement(NULL, resultPtr,
+	    Tcl_NewStringObj(channelNames[1], -1));
+    Tcl_SetObjResult(interp, resultPtr);
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclChannelNamesCmd --
+ *
+ *	This function is invoked to process the "chan names" and "file
+ *	channels" Tcl commands.  See the user documentation for details on
+ *	what they do.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclChannelNamesCmd(
+    ClientData clientData,
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    if (objc < 1 || objc > 2) {
+	Tcl_WrongNumArgs(interp, 1, objv, "?pattern?");
+	return TCL_ERROR;
+    }
+    return Tcl_GetChannelNamesEx(interp,
+	    ((objc == 1) ? NULL : TclGetString(objv[1])));
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclInitChanCmd --
+ *
+ *	This function is invoked to create the "chan" Tcl command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A Tcl command handle.
+ *
+ * Side effects:
+ *	None (since nothing is byte-compiled).
+ *
+ *----------------------------------------------------------------------
+ */
+
+Tcl_Command
+TclInitChanCmd(
+    Tcl_Interp *interp)
+{
+    /*
+     * Most commands are plugged directly together, but some are done via
+     * alias-like rewriting; [chan configure] is this way for security reasons
+     * (want overwriting of [fconfigure] to control that nicely), and [chan
+     * names] because the functionality isn't available as a separate command
+     * function at the moment.
+     */
+    static const EnsembleImplMap initMap[] = {
+	{"blocked",	Tcl_FblockedObjCmd,	TclCompileBasic1ArgCmd, NULL, NULL, 0},
+	{"close",	Tcl_CloseObjCmd,	TclCompileBasic1Or2ArgCmd, NULL, NULL, 0},
+	{"copy",	Tcl_FcopyObjCmd,	NULL, NULL, NULL, 0},
+	{"create",	TclChanCreateObjCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},		/* TIP #219 */
+	{"eof",		Tcl_EofObjCmd,		TclCompileBasic1ArgCmd, NULL, NULL, 0},
+	{"event",	Tcl_FileEventObjCmd,	TclCompileBasic2Or3ArgCmd, NULL, NULL, 0},
+	{"flush",	Tcl_FlushObjCmd,	TclCompileBasic1ArgCmd, NULL, NULL, 0},
+	{"gets",	Tcl_GetsObjCmd,		TclCompileBasic1Or2ArgCmd, NULL, NULL, 0},
+	{"names",	TclChannelNamesCmd,	TclCompileBasic0Or1ArgCmd, NULL, NULL, 0},
+	{"pending",	ChanPendingObjCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},		/* TIP #287 */
+	{"pipe",	ChanPipeObjCmd,		TclCompileBasic0ArgCmd, NULL, NULL, 0},		/* TIP #304 */
+	{"pop",		TclChanPopObjCmd,	TclCompileBasic1ArgCmd, NULL, NULL, 0},		/* TIP #230 */
+	{"postevent",	TclChanPostEventObjCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},	/* TIP #219 */
+	{"push",	TclChanPushObjCmd,	TclCompileBasic2ArgCmd, NULL, NULL, 0},		/* TIP #230 */
+	{"puts",	Tcl_PutsObjCmd,		NULL, NULL, NULL, 0},
+	{"read",	Tcl_ReadObjCmd,		NULL, NULL, NULL, 0},
+	{"seek",	Tcl_SeekObjCmd,		TclCompileBasic2Or3ArgCmd, NULL, NULL, 0},
+	{"tell",	Tcl_TellObjCmd,		TclCompileBasic1ArgCmd, NULL, NULL, 0},
+	{"truncate",	ChanTruncateObjCmd,	TclCompileBasic1Or2ArgCmd, NULL, NULL, 0},		/* TIP #208 */
+	{NULL, NULL, NULL, NULL, NULL, 0}
+    };
+    static const char *const extras[] = {
+	"configure",	"::fconfigure",
+	NULL
+    };
+    Tcl_Command ensemble;
+    Tcl_Obj *mapObj;
+    int i;
+
+    ensemble = TclMakeEnsemble(interp, "chan", initMap);
+    Tcl_GetEnsembleMappingDict(NULL, ensemble, &mapObj);
+    for (i=0 ; extras[i] ; i+=2) {
+	/*
+	 * Can assume that reference counts are all incremented.
+	 */
+
+	Tcl_DictObjPut(NULL, mapObj, Tcl_NewStringObj(extras[i], -1),
+		Tcl_NewStringObj(extras[i+1], -1));
+    }
+    Tcl_SetEnsembleMappingDict(interp, ensemble, mapObj);
+    return ensemble;
+}
+
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * End:
+ */