* Trash the filesystems cache.
     */

    fsRecPtr = tsdPtr->filesystemList;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = fsRecPtr->nextPtr;
	fsRecPtr->fsPtr = NULL;
	Tcl_Free(fsRecPtr);
	fsRecPtr = tmpFsRecPtr;
    }
    tsdPtr->filesystemList = NULL;
    tsdPtr->initialized = 0;
}

int

    /*
     * Refill the cache honouring the order.
     */

    list = NULL;
    fsRecPtr = tmpFsRecPtr;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = Tcl_Alloc(sizeof(FilesystemRecord));
	*tmpFsRecPtr = *fsRecPtr;
	tmpFsRecPtr->nextPtr = list;
	tmpFsRecPtr->prevPtr = NULL;
	list = tmpFsRecPtr;
	fsRecPtr = fsRecPtr->prevPtr;
    }
    tsdPtr->filesystemList = list;
    tsdPtr->filesystemEpoch = theFilesystemEpoch;
    Tcl_MutexUnlock(&filesystemMutex);

    while (toFree) {
	FilesystemRecord *next = toFree->nextPtr;

	toFree->fsPtr = NULL;
	Tcl_Free(toFree);
	toFree = next;
    }

    /*
     * Make sure the above gets released on thread exit.
     */

	FilesystemRecord *tmpFsRecPtr = fsRecPtr->nextPtr;

	/*
	 * The native filesystem is static, so we don't free it.
	 */

	if (fsRecPtr != &nativeFilesystemRecord) {
	    Tcl_Free(fsRecPtr);
	}
	fsRecPtr = tmpFsRecPtr;
    }
    if (++theFilesystemEpoch == 0) {
	++theFilesystemEpoch;
    }
    filesystemList = NULL;

{
    FilesystemRecord *newFilesystemPtr;

    if (fsPtr == NULL) {
	return TCL_ERROR;
    }

    newFilesystemPtr = Tcl_Alloc(sizeof(FilesystemRecord));

    newFilesystemPtr->clientData = clientData;
    newFilesystemPtr->fsPtr = fsPtr;

    /*
     * Is this lock and wait strictly speaking necessary? Since any iterators
     * out there will have grabbed a copy of the head of the list and be

	     * (which would of course lead to memory exceptions).
	     */

	    if (++theFilesystemEpoch == 0) {
		++theFilesystemEpoch;
	    }

	    Tcl_Free(fsRecPtr);

	    retVal = TCL_OK;
	} else {
	    fsRecPtr = fsRecPtr->nextPtr;
	}
    }

	    mode |= O_NOCTTY;
#else
	    if (interp != NULL) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"access mode \"%s\" not supported by this system",
			flag));
	    }
	    Tcl_Free(modeArgv);
	    return -1;
#endif

	} else if ((c == 'N') && (strcmp(flag, "NONBLOCK") == 0)) {
#ifdef O_NONBLOCK
	    mode |= O_NONBLOCK;
#else
	    if (interp != NULL) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"access mode \"%s\" not supported by this system",
			flag));
	    }
	    Tcl_Free(modeArgv);
	    return -1;
#endif

	} else if ((c == 'T') && (strcmp(flag, "TRUNC") == 0)) {
	    mode |= O_TRUNC;
	} else if ((c == 'B') && (strcmp(flag, "BINARY") == 0)) {
	    *binaryPtr = 1;
	} else {

	    if (interp != NULL) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"invalid access mode \"%s\": must be RDONLY, WRONLY, "
			"RDWR, APPEND, BINARY, CREAT, EXCL, NOCTTY, NONBLOCK,"
			" or TRUNC", flag));
	    }
	    Tcl_Free(modeArgv);
	    return -1;
	}
    }

    Tcl_Free(modeArgv);

    if (!gotRW) {
	if (interp != NULL) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "access mode must include either RDONLY, WRONLY, or RDWR",
		    -1));
	}

    }

    /*
     * When we unload this file, we need to divert the unloading so we can
     * unload and cleanup the temporary file correctly.
     */

    tvdlPtr = Tcl_Alloc(sizeof(FsDivertLoad));

    /*
     * Remember three pieces of information. This allows us to cleanup the
     * diverted load completely, on platforms which allow proper unloading of
     * code.
     */

	tvdlPtr->divertedFile = NULL;
	tvdlPtr->divertedFilesystem = NULL;
	Tcl_DecrRefCount(copyToPtr);
    }

    copyToPtr = NULL;

    divertedLoadHandle = Tcl_Alloc(sizeof(struct Tcl_LoadHandle_));
    divertedLoadHandle->clientData = tvdlPtr;
    divertedLoadHandle->findSymbolProcPtr = DivertFindSymbol;
    divertedLoadHandle->unloadFileProcPtr = DivertUnloadFile;
    *handlePtr = divertedLoadHandle;

    if (interp) {
	Tcl_ResetResult(interp);

	 * refCount from the Tcl_Filesystem to which this file belongs, which
	 * could then free up the filesystem if we are exiting.
	 */

	Tcl_DecrRefCount(tvdlPtr->divertedFile);
    }

    Tcl_Free(tvdlPtr);
    Tcl_Free(loadHandle);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FindSymbol --
 *

	 * refCount from the Tcl_Filesystem to which this file belongs, which
	 * could then free up the filesystem if we are exiting.
	 */

	Tcl_DecrRefCount(tvdlPtr->divertedFile);
    }

    Tcl_Free(tvdlPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSLink --
 *

 *---------------------------------------------------------------------------
 */

static void
NativeFreeInternalRep(
    ClientData clientData)
{
    Tcl_Free(clientData);
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSFileSystemInfo --
 *