shared_source/c_tcl_base_7_5_w_mods/tclwinreg.c

/* $Header$ */
/*
 * tclWinReg.c --
 *
 *      This file contains the implementation of the "registry" Tcl
 *      built-in command.  This command is built as a dynamically
 *      loadable extension in a separate DLL.
 *
 * Copyright (c) 1997 by Sun Microsystems, Inc.
 * Copyright (c) 1998-1999 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclwinreg.c,v 1.1.1.1 2001/06/13 04:50:03 dtashley Exp $
 */

#include <tclPort.h>
#include <stdlib.h>

#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#undef WIN32_LEAN_AND_MEAN

/*
 * TCL_STORAGE_CLASS is set unconditionally to DLLEXPORT because the
 * Registry_Init declaration is in the source file itself, which is only
 * accessed when we are building a library.
 */

#undef TCL_STORAGE_CLASS
#define TCL_STORAGE_CLASS DLLEXPORT

/*
 * The following macros convert between different endian ints.
 */

#define SWAPWORD(x) MAKEWORD(HIBYTE(x), LOBYTE(x))
#define SWAPLONG(x) MAKELONG(SWAPWORD(HIWORD(x)), SWAPWORD(LOWORD(x)))

/*
 * The following flag is used in OpenKeys to indicate that the specified
 * key should be created if it doesn't currently exist.
 */

#define REG_CREATE 1

/*
 * The following tables contain the mapping from registry root names
 * to the system predefined keys.
 */

static char *rootKeyNames[] = {
    "HKEY_LOCAL_MACHINE", "HKEY_USERS", "HKEY_CLASSES_ROOT",
    "HKEY_CURRENT_USER", "HKEY_CURRENT_CONFIG",
    "HKEY_PERFORMANCE_DATA", "HKEY_DYN_DATA", NULL
};

static HKEY rootKeys[] = {
    HKEY_LOCAL_MACHINE, HKEY_USERS, HKEY_CLASSES_ROOT, HKEY_CURRENT_USER,
    HKEY_CURRENT_CONFIG, HKEY_PERFORMANCE_DATA, HKEY_DYN_DATA
};

/*
 * The following table maps from registry types to strings.  Note that
 * the indices for this array are the same as the constants for the
 * known registry types so we don't need a separate table to hold the
 * mapping.
 */

static char *typeNames[] = {
    "none", "sz", "expand_sz", "binary", "dword",
    "dword_big_endian", "link", "multi_sz", "resource_list", NULL
};

static DWORD lastType = REG_RESOURCE_LIST;

/*
 * The following structures allow us to select between the Unicode and ASCII
 * interfaces at run time based on whether Unicode APIs are available.  The
 * Unicode APIs are preferable because they will handle characters outside
 * of the current code page.
 */

typedef struct RegWinProcs {
    int useWide;

    LONG (WINAPI *regConnectRegistryProc)(TCHAR *, HKEY, PHKEY);
    LONG (WINAPI *regCreateKeyExProc)(HKEY, CONST TCHAR *, DWORD, TCHAR *,
            DWORD, REGSAM, SECURITY_ATTRIBUTES *, HKEY *, DWORD *); 
    LONG (WINAPI *regDeleteKeyProc)(HKEY, CONST TCHAR *);
    LONG (WINAPI *regDeleteValueProc)(HKEY, CONST TCHAR *);
    LONG (WINAPI *regEnumKeyProc)(HKEY, DWORD, TCHAR *, DWORD);
    LONG (WINAPI *regEnumKeyExProc)(HKEY, DWORD, TCHAR *, DWORD *, DWORD *,
            TCHAR *, DWORD *, FILETIME *);
    LONG (WINAPI *regEnumValueProc)(HKEY, DWORD, TCHAR *, DWORD *, DWORD *,
            DWORD *, BYTE *, DWORD *);
    LONG (WINAPI *regOpenKeyExProc)(HKEY, CONST TCHAR *, DWORD, REGSAM,
            HKEY *);
    LONG (WINAPI *regQueryInfoKeyProc)(HKEY, TCHAR *, DWORD *, DWORD *,
            DWORD *, DWORD *, DWORD *, DWORD *, DWORD *, DWORD *, DWORD *,
            FILETIME *);
    LONG (WINAPI *regQueryValueExProc)(HKEY, CONST TCHAR *, DWORD *, DWORD *,
            BYTE *, DWORD *);
    LONG (WINAPI *regSetValueExProc)(HKEY, CONST TCHAR *, DWORD, DWORD,
            CONST BYTE*, DWORD);
} RegWinProcs;

static RegWinProcs *regWinProcs;

static RegWinProcs asciiProcs = {
    0,

    (LONG (WINAPI *)(TCHAR *, HKEY, PHKEY)) RegConnectRegistryA,
    (LONG (WINAPI *)(HKEY, CONST TCHAR *, DWORD, TCHAR *,
            DWORD, REGSAM, SECURITY_ATTRIBUTES *, HKEY *,
            DWORD *)) RegCreateKeyExA, 
    (LONG (WINAPI *)(HKEY, CONST TCHAR *)) RegDeleteKeyA,
    (LONG (WINAPI *)(HKEY, CONST TCHAR *)) RegDeleteValueA,
    (LONG (WINAPI *)(HKEY, DWORD, TCHAR *, DWORD)) RegEnumKeyA,
    (LONG (WINAPI *)(HKEY, DWORD, TCHAR *, DWORD *, DWORD *,
            TCHAR *, DWORD *, FILETIME *)) RegEnumKeyExA,
    (LONG (WINAPI *)(HKEY, DWORD, TCHAR *, DWORD *, DWORD *,
            DWORD *, BYTE *, DWORD *)) RegEnumValueA,
    (LONG (WINAPI *)(HKEY, CONST TCHAR *, DWORD, REGSAM,
            HKEY *)) RegOpenKeyExA,
    (LONG (WINAPI *)(HKEY, TCHAR *, DWORD *, DWORD *,
            DWORD *, DWORD *, DWORD *, DWORD *, DWORD *, DWORD *, DWORD *,
            FILETIME *)) RegQueryInfoKeyA,
    (LONG (WINAPI *)(HKEY, CONST TCHAR *, DWORD *, DWORD *,
            BYTE *, DWORD *)) RegQueryValueExA,
    (LONG (WINAPI *)(HKEY, CONST TCHAR *, DWORD, DWORD,
            CONST BYTE*, DWORD)) RegSetValueExA,
};

static RegWinProcs unicodeProcs = {
    1,

    (LONG (WINAPI *)(TCHAR *, HKEY, PHKEY)) RegConnectRegistryW,
    (LONG (WINAPI *)(HKEY, CONST TCHAR *, DWORD, TCHAR *,
            DWORD, REGSAM, SECURITY_ATTRIBUTES *, HKEY *,
            DWORD *)) RegCreateKeyExW, 
    (LONG (WINAPI *)(HKEY, CONST TCHAR *)) RegDeleteKeyW,
    (LONG (WINAPI *)(HKEY, CONST TCHAR *)) RegDeleteValueW,
    (LONG (WINAPI *)(HKEY, DWORD, TCHAR *, DWORD)) RegEnumKeyW,
    (LONG (WINAPI *)(HKEY, DWORD, TCHAR *, DWORD *, DWORD *,
            TCHAR *, DWORD *, FILETIME *)) RegEnumKeyExW,
    (LONG (WINAPI *)(HKEY, DWORD, TCHAR *, DWORD *, DWORD *,
            DWORD *, BYTE *, DWORD *)) RegEnumValueW,
    (LONG (WINAPI *)(HKEY, CONST TCHAR *, DWORD, REGSAM,
            HKEY *)) RegOpenKeyExW,
    (LONG (WINAPI *)(HKEY, TCHAR *, DWORD *, DWORD *,
            DWORD *, DWORD *, DWORD *, DWORD *, DWORD *, DWORD *, DWORD *,
            FILETIME *)) RegQueryInfoKeyW,
    (LONG (WINAPI *)(HKEY, CONST TCHAR *, DWORD *, DWORD *,
            BYTE *, DWORD *)) RegQueryValueExW,
    (LONG (WINAPI *)(HKEY, CONST TCHAR *, DWORD, DWORD,
            CONST BYTE*, DWORD)) RegSetValueExW,
};


/*
 * Declarations for functions defined in this file.
 */

static void             AppendSystemError(Tcl_Interp *interp, DWORD error);
static DWORD            ConvertDWORD(DWORD type, DWORD value);
static int              DeleteKey(Tcl_Interp *interp, Tcl_Obj *keyNameObj);
static int              DeleteValue(Tcl_Interp *interp, Tcl_Obj *keyNameObj,
                            Tcl_Obj *valueNameObj);
static int              GetKeyNames(Tcl_Interp *interp, Tcl_Obj *keyNameObj,
                            Tcl_Obj *patternObj);
static int              GetType(Tcl_Interp *interp, Tcl_Obj *keyNameObj,
                            Tcl_Obj *valueNameObj);
static int              GetValue(Tcl_Interp *interp, Tcl_Obj *keyNameObj,
                            Tcl_Obj *valueNameObj);
static int              GetValueNames(Tcl_Interp *interp, Tcl_Obj *keyNameObj,
                            Tcl_Obj *patternObj);
static int              OpenKey(Tcl_Interp *interp, Tcl_Obj *keyNameObj,
                            REGSAM mode, int flags, HKEY *keyPtr);
static DWORD            OpenSubKey(char *hostName, HKEY rootKey,
                            char *keyName, REGSAM mode, int flags,
                            HKEY *keyPtr);
static int              ParseKeyName(Tcl_Interp *interp, char *name,
                            char **hostNamePtr, HKEY *rootKeyPtr,
                            char **keyNamePtr);
static DWORD            RecursiveDeleteKey(HKEY hStartKey, TCHAR * pKeyName);
static int              RegistryObjCmd(ClientData clientData,
                            Tcl_Interp *interp, int objc,
                            Tcl_Obj * CONST objv[]);
static int              SetValue(Tcl_Interp *interp, Tcl_Obj *keyNameObj,
                            Tcl_Obj *valueNameObj, Tcl_Obj *dataObj,
                            Tcl_Obj *typeObj);

EXTERN int Registry_Init(Tcl_Interp *interp);

/*
 *----------------------------------------------------------------------
 *
 * Registry_Init --
 *
 *      This procedure initializes the registry command.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

int
Registry_Init(
    Tcl_Interp *interp)
{
    if (!Tcl_InitStubs(interp, "8.0", 0)) {
        return TCL_ERROR;
    }

    /*
     * Determine if the unicode interfaces are available and select the
     * appropriate registry function table.
     */

    if (TclWinGetPlatformId() == VER_PLATFORM_WIN32_NT) {
        regWinProcs = &unicodeProcs;
    } else {
        regWinProcs = &asciiProcs;
    }

    Tcl_CreateObjCommand(interp, "registry", RegistryObjCmd, NULL, NULL);
    return Tcl_PkgProvide(interp, "registry", "1.0");
}

/*
 *----------------------------------------------------------------------
 *
 * RegistryObjCmd --
 *
 *      This function implements the Tcl "registry" command.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
RegistryObjCmd(
    ClientData clientData,      /* Not used. */
    Tcl_Interp *interp,         /* Current interpreter. */
    int objc,                   /* Number of arguments. */
    Tcl_Obj * CONST objv[])     /* Argument values. */
{
    int index;
    char *errString;

    static char *subcommands[] = { "delete", "get", "keys", "set", "type",
                                   "values", (char *) NULL };
    enum SubCmdIdx { DeleteIdx, GetIdx, KeysIdx, SetIdx, TypeIdx, ValuesIdx };

    if (objc < 2) {
        Tcl_WrongNumArgs(interp, objc, objv, "option ?arg arg ...?");
        return TCL_ERROR;
    }

    if (Tcl_GetIndexFromObj(interp, objv[1], subcommands, "option", 0, &index)
            != TCL_OK) {
        return TCL_ERROR;
    }

    switch (index) {
        case DeleteIdx:                 /* delete */
            if (objc == 3) {
                return DeleteKey(interp, objv[2]);
            } else if (objc == 4) {
                return DeleteValue(interp, objv[2], objv[3]);
            }
            errString = "keyName ?valueName?";
            break;
        case GetIdx:                    /* get */
            if (objc == 4) {
                return GetValue(interp, objv[2], objv[3]);
            }
            errString = "keyName valueName";
            break;
        case KeysIdx:                   /* keys */
            if (objc == 3) {
                return GetKeyNames(interp, objv[2], NULL);
            } else if (objc == 4) {
                return GetKeyNames(interp, objv[2], objv[3]);
            }
            errString = "keyName ?pattern?";
            break;
        case SetIdx:                    /* set */
            if (objc == 3) {
                HKEY key;

                /*
                 * Create the key and then close it immediately.
                 */

                if (OpenKey(interp, objv[2], KEY_ALL_ACCESS, 1, &key)
                        != TCL_OK) {
                    return TCL_ERROR;
                }
                RegCloseKey(key);
                return TCL_OK;
            } else if (objc == 5 || objc == 6) {
                Tcl_Obj *typeObj = (objc == 5) ? NULL : objv[5];
                return SetValue(interp, objv[2], objv[3], objv[4], typeObj);
            }
            errString = "keyName ?valueName data ?type??";
            break;
        case TypeIdx:                   /* type */
            if (objc == 4) {
                return GetType(interp, objv[2], objv[3]);
            }
            errString = "keyName valueName";
            break;
        case ValuesIdx:                 /* values */
            if (objc == 3) {
                return GetValueNames(interp, objv[2], NULL);
            } else if (objc == 4) {
                return GetValueNames(interp, objv[2], objv[3]);
            }
            errString = "keyName ?pattern?";
            break;
    }
    Tcl_WrongNumArgs(interp, 2, objv, errString);
    return TCL_ERROR;
}

/*
 *----------------------------------------------------------------------
 *
 * DeleteKey --
 *
 *      This function deletes a registry key.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
DeleteKey(
    Tcl_Interp *interp,         /* Current interpreter. */
    Tcl_Obj *keyNameObj)        /* Name of key to delete. */
{
    char *tail, *buffer, *hostName, *keyName;
    HKEY rootKey, subkey;
    DWORD result;
    int length;
    Tcl_Obj *resultPtr;
    Tcl_DString buf;

    /*
     * Find the parent of the key being deleted and open it.
     */

    keyName = Tcl_GetStringFromObj(keyNameObj, &length);
    buffer = ckalloc(length + 1);
    strcpy(buffer, keyName);

    if (ParseKeyName(interp, buffer, &hostName, &rootKey, &keyName)
            != TCL_OK) {
        ckfree(buffer);
        return TCL_ERROR;
    }

    resultPtr = Tcl_GetObjResult(interp);
    if (*keyName == '\0') {
        Tcl_AppendToObj(resultPtr, "bad key: cannot delete root keys", -1);
        ckfree(buffer);
        return TCL_ERROR;
    }

    tail = strrchr(keyName, '\\');
    if (tail) {
        *tail++ = '\0';
    } else {
        tail = keyName;
        keyName = NULL;
    }

    result = OpenSubKey(hostName, rootKey, keyName,
            KEY_ENUMERATE_SUB_KEYS | DELETE, 0, &subkey);
    if (result != ERROR_SUCCESS) {
        ckfree(buffer);
        if (result == ERROR_FILE_NOT_FOUND) {
            return TCL_OK;
        } else {
            Tcl_AppendToObj(resultPtr, "unable to delete key: ", -1);
            AppendSystemError(interp, result);
            return TCL_ERROR;
        }
    }

    /*
     * Now we recursively delete the key and everything below it.
     */

    tail = Tcl_WinUtfToTChar(tail, -1, &buf);
    result = RecursiveDeleteKey(subkey, tail);
    Tcl_DStringFree(&buf);

    if (result != ERROR_SUCCESS && result != ERROR_FILE_NOT_FOUND) {
        Tcl_AppendToObj(resultPtr, "unable to delete key: ", -1);
        AppendSystemError(interp, result);
        result = TCL_ERROR;
    } else {
        result = TCL_OK;
    }

    RegCloseKey(subkey);
    ckfree(buffer);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * DeleteValue --
 *
 *      This function deletes a value from a registry key.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
DeleteValue(
    Tcl_Interp *interp,         /* Current interpreter. */
    Tcl_Obj *keyNameObj,        /* Name of key. */
    Tcl_Obj *valueNameObj)      /* Name of value to delete. */
{
    HKEY key;
    char *valueName;
    int length;
    DWORD result;
    Tcl_Obj *resultPtr;
    Tcl_DString ds;

    /*
     * Attempt to open the key for deletion.
     */

    if (OpenKey(interp, keyNameObj, KEY_SET_VALUE, 0, &key)
            != TCL_OK) {
        return TCL_ERROR;
    }

    resultPtr = Tcl_GetObjResult(interp);
    valueName = Tcl_GetStringFromObj(valueNameObj, &length);
    Tcl_WinUtfToTChar(valueName, length, &ds);
    result = (*regWinProcs->regDeleteValueProc)(key, Tcl_DStringValue(&ds));
    Tcl_DStringFree(&ds);
    if (result != ERROR_SUCCESS) {
        Tcl_AppendStringsToObj(resultPtr, "unable to delete value \"",
                Tcl_GetString(valueNameObj), "\" from key \"",
                Tcl_GetString(keyNameObj), "\": ", NULL);
        AppendSystemError(interp, result);
        result = TCL_ERROR;
    } else {
        result = TCL_OK;
    }
    RegCloseKey(key);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * GetKeyNames --
 *
 *      This function enumerates the subkeys of a given key.  If the
 *      optional pattern is supplied, then only keys that match the
 *      pattern will be returned.
 *
 * Results:
 *      Returns the list of subkeys in the result object of the
 *      interpreter, or an error message on failure.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
GetKeyNames(
    Tcl_Interp *interp,         /* Current interpreter. */
    Tcl_Obj *keyNameObj,        /* Key to enumerate. */
    Tcl_Obj *patternObj)        /* Optional match pattern. */
{
    HKEY key;
    DWORD index;
    char buffer[MAX_PATH+1], *pattern, *name;
    Tcl_Obj *resultPtr;
    int result = TCL_OK;
    Tcl_DString ds;

    /*
     * Attempt to open the key for enumeration.
     */

    if (OpenKey(interp, keyNameObj, KEY_ENUMERATE_SUB_KEYS, 0, &key)
            != TCL_OK) {
        return TCL_ERROR;
    }

    if (patternObj) {
        pattern = Tcl_GetString(patternObj);
    } else {
        pattern = NULL;
    }

    /*
     * Enumerate over the subkeys until we get an error, indicating the
     * end of the list.
     */

    resultPtr = Tcl_GetObjResult(interp);
    for (index = 0; (*regWinProcs->regEnumKeyProc)(key, index, buffer,
            MAX_PATH+1) == ERROR_SUCCESS; index++) {
        Tcl_WinTCharToUtf((TCHAR *) buffer, -1, &ds);
        name = Tcl_DStringValue(&ds);
        if (pattern && !Tcl_StringMatch(name, pattern)) {
            Tcl_DStringFree(&ds);
            continue;
        }
        result = Tcl_ListObjAppendElement(interp, resultPtr,
                Tcl_NewStringObj(name, Tcl_DStringLength(&ds)));
        Tcl_DStringFree(&ds);
        if (result != TCL_OK) {
            break;
        }
    }

    RegCloseKey(key);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * GetType --
 *
 *      This function gets the type of a given registry value and
 *      places it in the interpreter result.
 *
 * Results:
 *      Returns a normal Tcl result.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
GetType(
    Tcl_Interp *interp,         /* Current interpreter. */
    Tcl_Obj *keyNameObj,        /* Name of key. */
    Tcl_Obj *valueNameObj)      /* Name of value to get. */
{
    HKEY key;
    Tcl_Obj *resultPtr;
    DWORD result;
    DWORD type;
    Tcl_DString ds;
    char *valueName;
    int length;

    /*
     * Attempt to open the key for reading.
     */

    if (OpenKey(interp, keyNameObj, KEY_QUERY_VALUE, 0, &key)
            != TCL_OK) {
        return TCL_ERROR;
    }

    /*
     * Get the type of the value.
     */

    resultPtr = Tcl_GetObjResult(interp);

    valueName = Tcl_GetStringFromObj(valueNameObj, &length);
    valueName = Tcl_WinUtfToTChar(valueName, length, &ds);
    result = (*regWinProcs->regQueryValueExProc)(key, valueName, NULL, &type,
            NULL, NULL);
    Tcl_DStringFree(&ds);
    RegCloseKey(key);

    if (result != ERROR_SUCCESS) {
        Tcl_AppendStringsToObj(resultPtr, "unable to get type of value \"",
                Tcl_GetString(valueNameObj), "\" from key \"",
                Tcl_GetString(keyNameObj), "\": ", NULL);
        AppendSystemError(interp, result);
        return TCL_ERROR;
    }

    /*
     * Set the type into the result.  Watch out for unknown types.
     * If we don't know about the type, just use the numeric value.
     */

    if (type > lastType || type < 0) {
        Tcl_SetIntObj(resultPtr, type);
    } else {
        Tcl_SetStringObj(resultPtr, typeNames[type], -1);
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * GetValue --
 *
 *      This function gets the contents of a registry value and places
 *      a list containing the data and the type in the interpreter
 *      result.
 *
 * Results:
 *      Returns a normal Tcl result.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
GetValue(
    Tcl_Interp *interp,         /* Current interpreter. */
    Tcl_Obj *keyNameObj,        /* Name of key. */
    Tcl_Obj *valueNameObj)      /* Name of value to get. */
{
    HKEY key;
    char *valueName;
    DWORD result, length, type;
    Tcl_Obj *resultPtr;
    Tcl_DString data, buf;
    int nameLen;

    /*
     * Attempt to open the key for reading.
     */

    if (OpenKey(interp, keyNameObj, KEY_QUERY_VALUE, 0, &key)
            != TCL_OK) {
        return TCL_ERROR;
    }

    /*
     * Initialize a Dstring to maximum statically allocated size
     * we could get one more byte by avoiding Tcl_DStringSetLength()
     * and just setting length to TCL_DSTRING_STATIC_SIZE, but this
     * should be safer if the implementation of Dstrings changes.
     *
     * This allows short values to be read from the registy in one call.
     * Longer values need a second call with an expanded DString.
     */

    Tcl_DStringInit(&data);
    length = TCL_DSTRING_STATIC_SIZE - 1;
    Tcl_DStringSetLength(&data, length);

    resultPtr = Tcl_GetObjResult(interp);

    valueName = Tcl_GetStringFromObj(valueNameObj, &nameLen);
    valueName = Tcl_WinUtfToTChar(valueName, nameLen, &buf);

    result = (*regWinProcs->regQueryValueExProc)(key, valueName, NULL, &type,
            (BYTE *) Tcl_DStringValue(&data), &length);
    while (result == ERROR_MORE_DATA) {
        /*
         * The Windows docs say that in this error case, we just need
         * to expand our buffer and request more data.
         * Required for HKEY_PERFORMANCE_DATA
         */
        length *= 2;
        Tcl_DStringSetLength(&data, length);
        result = (*regWinProcs->regQueryValueExProc)(key, valueName, NULL,
                &type, (BYTE *) Tcl_DStringValue(&data), &length);
    }
    Tcl_DStringFree(&buf);
    RegCloseKey(key);
    if (result != ERROR_SUCCESS) {
        Tcl_AppendStringsToObj(resultPtr, "unable to get value \"",
                Tcl_GetString(valueNameObj), "\" from key \"",
                Tcl_GetString(keyNameObj), "\": ", NULL);
        AppendSystemError(interp, result);
        Tcl_DStringFree(&data);
        return TCL_ERROR;
    }

    /*
     * If the data is a 32-bit quantity, store it as an integer object.  If it
     * is a multi-string, store it as a list of strings.  For null-terminated
     * strings, append up the to first null.  Otherwise, store it as a binary
     * string.
     */

    if (type == REG_DWORD || type == REG_DWORD_BIG_ENDIAN) {
        Tcl_SetIntObj(resultPtr, ConvertDWORD(type,
                *((DWORD*) Tcl_DStringValue(&data))));
    } else if (type == REG_MULTI_SZ) {
        char *p = Tcl_DStringValue(&data);
        char *end = Tcl_DStringValue(&data) + length;

        /*
         * Multistrings are stored as an array of null-terminated strings,
         * terminated by two null characters.  Also do a bounds check in
         * case we get bogus data.
         */
 
        while (p < end  && ((regWinProcs->useWide) 
                ? *((Tcl_UniChar *)p) : *p) != 0) {
            Tcl_WinTCharToUtf((TCHAR *) p, -1, &buf);
            Tcl_ListObjAppendElement(interp, resultPtr,
                    Tcl_NewStringObj(Tcl_DStringValue(&buf),
                            Tcl_DStringLength(&buf)));
            if (regWinProcs->useWide) {
                while (*((Tcl_UniChar *)p)++ != 0) {}
            } else {
                while (*p++ != '\0') {}
            }
            Tcl_DStringFree(&buf);
        }
    } else if ((type == REG_SZ) || (type == REG_EXPAND_SZ)) {
        Tcl_WinTCharToUtf((TCHAR *) Tcl_DStringValue(&data), -1, &buf);
        Tcl_SetStringObj(resultPtr, Tcl_DStringValue(&buf),
                Tcl_DStringLength(&buf));
        Tcl_DStringFree(&buf);
    } else {
        /*
         * Save binary data as a byte array.
         */

        Tcl_SetByteArrayObj(resultPtr, Tcl_DStringValue(&data), length);
    }
    Tcl_DStringFree(&data);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * GetValueNames --
 *
 *      This function enumerates the values of the a given key.  If
 *      the optional pattern is supplied, then only value names that
 *      match the pattern will be returned.
 *
 * Results:
 *      Returns the list of value names in the result object of the
 *      interpreter, or an error message on failure.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
GetValueNames(
    Tcl_Interp *interp,         /* Current interpreter. */
    Tcl_Obj *keyNameObj,        /* Key to enumerate. */
    Tcl_Obj *patternObj)        /* Optional match pattern. */
{
    HKEY key;
    Tcl_Obj *resultPtr;
    DWORD index, size, maxSize, result;
    Tcl_DString buffer, ds;
    char *pattern, *name;

    /*
     * Attempt to open the key for enumeration.
     */

    if (OpenKey(interp, keyNameObj, KEY_QUERY_VALUE, 0, &key)
            != TCL_OK) {
        return TCL_ERROR;
    }

    resultPtr = Tcl_GetObjResult(interp);

    /*
     * Query the key to determine the appropriate buffer size to hold the
     * largest value name plus the terminating null.
     */

    result = (*regWinProcs->regQueryInfoKeyProc)(key, NULL, NULL, NULL, NULL,
            NULL, NULL, &index, &maxSize, NULL, NULL, NULL);
    if (result != ERROR_SUCCESS) {
        Tcl_AppendStringsToObj(resultPtr, "unable to query key \"",
                Tcl_GetString(keyNameObj), "\": ", NULL);
        AppendSystemError(interp, result);
        RegCloseKey(key);
        result = TCL_ERROR;
        goto done;
    }
    maxSize++;


    Tcl_DStringInit(&buffer);
    Tcl_DStringSetLength(&buffer,
            (regWinProcs->useWide) ? maxSize*2 : maxSize);
    index = 0;
    result = TCL_OK;

    if (patternObj) {
        pattern = Tcl_GetString(patternObj);
    } else {
        pattern = NULL;
    }

    /*
     * Enumerate the values under the given subkey until we get an error,
     * indicating the end of the list.  Note that we need to reset size
     * after each iteration because RegEnumValue smashes the old value.
     */

    size = maxSize;
    while ((*regWinProcs->regEnumValueProc)(key, index,
            Tcl_DStringValue(&buffer), &size, NULL, NULL, NULL, NULL)
            == ERROR_SUCCESS) {

        if (regWinProcs->useWide) {
            size *= 2;
        }

        Tcl_WinTCharToUtf((TCHAR *) Tcl_DStringValue(&buffer), size, &ds);
        name = Tcl_DStringValue(&ds);
        if (!pattern || Tcl_StringMatch(name, pattern)) {
            result = Tcl_ListObjAppendElement(interp, resultPtr,
                    Tcl_NewStringObj(name, Tcl_DStringLength(&ds)));
            if (result != TCL_OK) {
                Tcl_DStringFree(&ds);
                break;
            }
        }
        Tcl_DStringFree(&ds);

        index++;
        size = maxSize;
    }
    Tcl_DStringFree(&buffer);

    done:
    RegCloseKey(key);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * OpenKey --
 *
 *      This function opens the specified key.  This function is a
 *      simple wrapper around ParseKeyName and OpenSubKey.
 *
 * Results:
 *      Returns the opened key in the keyPtr argument and a Tcl
 *      result code.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
OpenKey(
    Tcl_Interp *interp,         /* Current interpreter. */
    Tcl_Obj *keyNameObj,        /* Key to open. */
    REGSAM mode,                /* Access mode. */
    int flags,                  /* 0 or REG_CREATE. */
    HKEY *keyPtr)               /* Returned HKEY. */
{
    char *keyName, *buffer, *hostName;
    int length;
    HKEY rootKey;
    DWORD result;

    keyName = Tcl_GetStringFromObj(keyNameObj, &length);
    buffer = ckalloc(length + 1);
    strcpy(buffer, keyName);

    result = ParseKeyName(interp, buffer, &hostName, &rootKey, &keyName);
    if (result == TCL_OK) {
        result = OpenSubKey(hostName, rootKey, keyName, mode, flags, keyPtr);
        if (result != ERROR_SUCCESS) {
            Tcl_Obj *resultPtr = Tcl_GetObjResult(interp);
            Tcl_AppendToObj(resultPtr, "unable to open key: ", -1);
            AppendSystemError(interp, result);
            result = TCL_ERROR;
        } else {
            result = TCL_OK;
        }
    }

    ckfree(buffer);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * OpenSubKey --
 *
 *      This function opens a given subkey of a root key on the
 *      specified host.
 *
 * Results:
 *      Returns the opened key in the keyPtr and a Windows error code
 *      as the return value.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static DWORD
OpenSubKey(
    char *hostName,             /* Host to access, or NULL for local. */
    HKEY rootKey,               /* Root registry key. */
    char *keyName,              /* Subkey name. */
    REGSAM mode,                /* Access mode. */
    int flags,                  /* 0 or REG_CREATE. */
    HKEY *keyPtr)               /* Returned HKEY. */
{
    DWORD result;
    Tcl_DString buf;

    /*
     * Attempt to open the root key on a remote host if necessary.
     */

    if (hostName) {
        hostName = Tcl_WinUtfToTChar(hostName, -1, &buf);
        result = (*regWinProcs->regConnectRegistryProc)(hostName, rootKey,
                &rootKey);
        Tcl_DStringFree(&buf);
        if (result != ERROR_SUCCESS) {
            return result;
        }
    }

    /*
     * Now open the specified key with the requested permissions.  Note
     * that this key must be closed by the caller.
     */

    keyName = Tcl_WinUtfToTChar(keyName, -1, &buf);
    if (flags & REG_CREATE) {
        DWORD create;
        result = (*regWinProcs->regCreateKeyExProc)(rootKey, keyName, 0, "",
                REG_OPTION_NON_VOLATILE, mode, NULL, keyPtr, &create);
    } else {
        if (rootKey == HKEY_PERFORMANCE_DATA) {
            /*
             * Here we fudge it for this special root key.
             * See MSDN for more info on HKEY_PERFORMANCE_DATA and
             * the peculiarities surrounding it
             */
            *keyPtr = HKEY_PERFORMANCE_DATA;
            result = ERROR_SUCCESS;
        } else {
            result = (*regWinProcs->regOpenKeyExProc)(rootKey, keyName, 0,
                    mode, keyPtr);
        }
    }
    Tcl_DStringFree(&buf);

    /*
     * Be sure to close the root key since we are done with it now.
     */

    if (hostName) {
        RegCloseKey(rootKey);
    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * ParseKeyName --
 *
 *      This function parses a key name into the host, root, and subkey
 *      parts.
 *
 * Results:
 *      The pointers to the start of the host and subkey names are
 *      returned in the hostNamePtr and keyNamePtr variables.  The
 *      specified root HKEY is returned in rootKeyPtr.  Returns
 *      a standard Tcl result.
 *
 *
 * Side effects:
 *      Modifies the name string by inserting nulls.
 *
 *----------------------------------------------------------------------
 */

static int
ParseKeyName(
    Tcl_Interp *interp,         /* Current interpreter. */
    char *name,
    char **hostNamePtr,
    HKEY *rootKeyPtr,
    char **keyNamePtr)
{
    char *rootName;
    int result, index;
    Tcl_Obj *rootObj, *resultPtr = Tcl_GetObjResult(interp);

    /*
     * Split the key into host and root portions.
     */

    *hostNamePtr = *keyNamePtr = rootName = NULL;
    if (name[0] == '\\') {
        if (name[1] == '\\') {
            *hostNamePtr = name;
            for (rootName = name+2; *rootName != '\0'; rootName++) {
                if (*rootName == '\\') {
                    *rootName++ = '\0';
                    break;
                }
            }
        }
    } else {
        rootName = name;
    }
    if (!rootName) {
        Tcl_AppendStringsToObj(resultPtr, "bad key \"", name,
                "\": must start with a valid root", NULL);
        return TCL_ERROR;
    }

    /*
     * Split the root into root and subkey portions.
     */

    for (*keyNamePtr = rootName; **keyNamePtr != '\0'; (*keyNamePtr)++) {
        if (**keyNamePtr == '\\') {
            **keyNamePtr = '\0';
            (*keyNamePtr)++;
            break;
        }
    }

    /*
     * Look for a matching root name.
     */

    rootObj = Tcl_NewStringObj(rootName, -1);
    result = Tcl_GetIndexFromObj(interp, rootObj, rootKeyNames, "root name",
            TCL_EXACT, &index);
    Tcl_DecrRefCount(rootObj);
    if (result != TCL_OK) {
        return TCL_ERROR;
    }
    *rootKeyPtr = rootKeys[index];
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * RecursiveDeleteKey --
 *
 *      This function recursively deletes all the keys below a starting
 *      key.  Although Windows 95 does this automatically, we still need
 *      to do this for Windows NT.
 *
 * Results:
 *      Returns a Windows error code.
 *
 * Side effects:
 *      Deletes all of the keys and values below the given key.
 *
 *----------------------------------------------------------------------
 */

static DWORD
RecursiveDeleteKey(
    HKEY startKey,              /* Parent of key to be deleted. */
    char *keyName)              /* Name of key to be deleted in external
                                 * encoding, not UTF. */
{
    DWORD result, size, maxSize;
    Tcl_DString subkey;
    HKEY hKey;

    /*
     * Do not allow NULL or empty key name.
     */

    if (!keyName || *keyName == '\0') {
        return ERROR_BADKEY;
    }

    result = (*regWinProcs->regOpenKeyExProc)(startKey, keyName, 0,
            KEY_ENUMERATE_SUB_KEYS | DELETE | KEY_QUERY_VALUE, &hKey);
    if (result != ERROR_SUCCESS) {
        return result;
    }
    result = (*regWinProcs->regQueryInfoKeyProc)(hKey, NULL, NULL, NULL, NULL,
            &maxSize, NULL, NULL, NULL, NULL, NULL, NULL);
    maxSize++;
    if (result != ERROR_SUCCESS) {
        return result;
    }

    Tcl_DStringInit(&subkey);
    Tcl_DStringSetLength(&subkey,
            (regWinProcs->useWide) ? maxSize * 2 : maxSize);

    while (result == ERROR_SUCCESS) {
        /*
         * Always get index 0 because key deletion changes ordering.
         */

        size = maxSize;
        result=(*regWinProcs->regEnumKeyExProc)(hKey, 0,
                Tcl_DStringValue(&subkey), &size, NULL, NULL, NULL, NULL);
        if (result == ERROR_NO_MORE_ITEMS) {
            result = (*regWinProcs->regDeleteKeyProc)(startKey, keyName);
            break;
        } else if (result == ERROR_SUCCESS) {
            result = RecursiveDeleteKey(hKey, Tcl_DStringValue(&subkey));
        }
    }
    Tcl_DStringFree(&subkey);
    RegCloseKey(hKey);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * SetValue --
 *
 *      This function sets the contents of a registry value.  If
 *      the key or value does not exist, it will be created.  If it
 *      does exist, then the data and type will be replaced.
 *
 * Results:
 *      Returns a normal Tcl result.
 *
 * Side effects:
 *      May create new keys or values.
 *
 *----------------------------------------------------------------------
 */

static int
SetValue(
    Tcl_Interp *interp,         /* Current interpreter. */
    Tcl_Obj *keyNameObj,        /* Name of key. */
    Tcl_Obj *valueNameObj,      /* Name of value to set. */
    Tcl_Obj *dataObj,           /* Data to be written. */
    Tcl_Obj *typeObj)           /* Type of data to be written. */
{
    DWORD type, result;
    HKEY key;
    int length;
    char *valueName;
    Tcl_Obj *resultPtr;
    Tcl_DString nameBuf;

    if (typeObj == NULL) {
        type = REG_SZ;
    } else if (Tcl_GetIndexFromObj(interp, typeObj, typeNames, "type",
            0, (int *) &type) != TCL_OK) {
        if (Tcl_GetIntFromObj(NULL, typeObj, (int*) &type) != TCL_OK) {
            return TCL_ERROR;
        }
        Tcl_ResetResult(interp);
    }
    if (OpenKey(interp, keyNameObj, KEY_ALL_ACCESS, 1, &key) != TCL_OK) {
        return TCL_ERROR;
    }

    valueName = Tcl_GetStringFromObj(valueNameObj, &length);
    valueName = Tcl_WinUtfToTChar(valueName, length, &nameBuf);
    resultPtr = Tcl_GetObjResult(interp);

    if (type == REG_DWORD || type == REG_DWORD_BIG_ENDIAN) {
        DWORD value;
        if (Tcl_GetIntFromObj(interp, dataObj, (int*) &value) != TCL_OK) {
            RegCloseKey(key);
            Tcl_DStringFree(&nameBuf);
            return TCL_ERROR;
        }

        value = ConvertDWORD(type, value);
        result = (*regWinProcs->regSetValueExProc)(key, valueName, 0, type,
                (BYTE*) &value, sizeof(DWORD));
    } else if (type == REG_MULTI_SZ) {
        Tcl_DString data, buf;
        int objc, i;
        Tcl_Obj **objv;

        if (Tcl_ListObjGetElements(interp, dataObj, &objc, &objv) != TCL_OK) {
            RegCloseKey(key);
            Tcl_DStringFree(&nameBuf);
            return TCL_ERROR;
        }

        /*
         * Append the elements as null terminated strings.  Note that
         * we must not assume the length of the string in case there are
         * embedded nulls, which aren't allowed in REG_MULTI_SZ values.
         */

        Tcl_DStringInit(&data);
        for (i = 0; i < objc; i++) {
            Tcl_DStringAppend(&data, Tcl_GetString(objv[i]), -1);

            /*
             * Add a null character to separate this value from the next.
             * We accomplish this by growing the string by one byte.  Since the
             * DString always tacks on an extra null byte, the new byte will
             * already be set to null.
             */

            Tcl_DStringSetLength(&data, Tcl_DStringLength(&data)+1);
        }

        Tcl_WinUtfToTChar(Tcl_DStringValue(&data), Tcl_DStringLength(&data)+1,
                &buf);
        result = (*regWinProcs->regSetValueExProc)(key, valueName, 0, type,
                (BYTE *) Tcl_DStringValue(&buf),
                (DWORD) Tcl_DStringLength(&buf));
        Tcl_DStringFree(&data);
        Tcl_DStringFree(&buf);
    } else if (type == REG_SZ || type == REG_EXPAND_SZ) {
        Tcl_DString buf;
        char *data = Tcl_GetStringFromObj(dataObj, &length);

        data = Tcl_WinUtfToTChar(data, length, &buf);

        /*
         * Include the null in the length, padding if needed for Unicode.
         */

        if (regWinProcs->useWide) {
            Tcl_DStringSetLength(&buf, Tcl_DStringLength(&buf)+1);
        }
        length = Tcl_DStringLength(&buf) + 1;

        result = (*regWinProcs->regSetValueExProc)(key, valueName, 0, type,
                (BYTE*)data, length);
        Tcl_DStringFree(&buf);
    } else {
        char *data;

        /*
         * Store binary data in the registry.
         */

        data = Tcl_GetByteArrayFromObj(dataObj, &length);
        result = (*regWinProcs->regSetValueExProc)(key, valueName, 0, type,
                (BYTE *)data, length);
    }
    Tcl_DStringFree(&nameBuf);
    RegCloseKey(key);
    if (result != ERROR_SUCCESS) {
        Tcl_AppendToObj(resultPtr, "unable to set value: ", -1);
        AppendSystemError(interp, result);
        return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * AppendSystemError --
 *
 *      This routine formats a Windows system error message and places
 *      it into the interpreter result.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static void
AppendSystemError(
    Tcl_Interp *interp,         /* Current interpreter. */
    DWORD error)                /* Result code from error. */
{
    int length;
    WCHAR *wMsgPtr;
    char *msg;
    char id[TCL_INTEGER_SPACE], msgBuf[24 + TCL_INTEGER_SPACE];
    Tcl_DString ds;
    Tcl_Obj *resultPtr = Tcl_GetObjResult(interp);

    length = FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM
            | FORMAT_MESSAGE_ALLOCATE_BUFFER, NULL, error,
            MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (WCHAR *) &wMsgPtr,
            0, NULL);
    if (length == 0) {
        char *msgPtr;

        length = FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM
                | FORMAT_MESSAGE_ALLOCATE_BUFFER, NULL, error,
                MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (char *) &msgPtr,
                0, NULL);
        if (length > 0) {
            wMsgPtr = (WCHAR *) LocalAlloc(LPTR, (length + 1) * sizeof(WCHAR));
            MultiByteToWideChar(CP_ACP, 0, msgPtr, length + 1, wMsgPtr,
                    length + 1);
            LocalFree(msgPtr);
        }
    }
    if (length == 0) {
        if (error == ERROR_CALL_NOT_IMPLEMENTED) {
            msg = "function not supported under Win32s";
        } else {
            sprintf(msgBuf, "unknown error: %d", error);
            msg = msgBuf;
        }
    } else {
        Tcl_Encoding encoding;

        encoding = Tcl_GetEncoding(NULL, "unicode");
        Tcl_ExternalToUtfDString(encoding, (char *) wMsgPtr, -1, &ds);
        Tcl_FreeEncoding(encoding);
        LocalFree(wMsgPtr);

        msg = Tcl_DStringValue(&ds);
        length = Tcl_DStringLength(&ds);

        /*
         * Trim the trailing CR/LF from the system message.
         */
        if (msg[length-1] == '\n') {
            msg[--length] = 0;
        }
        if (msg[length-1] == '\r') {
            msg[--length] = 0;
        }
    }

    sprintf(id, "%d", error);
    Tcl_SetErrorCode(interp, "WINDOWS", id, msg, (char *) NULL);
    Tcl_AppendToObj(resultPtr, msg, length);

    if (length != 0) {
        Tcl_DStringFree(&ds);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * ConvertDWORD --
 *
 *      This function determines whether a DWORD needs to be byte
 *      swapped, and returns the appropriately swapped value.
 *
 * Results:
 *      Returns a converted DWORD.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static DWORD
ConvertDWORD(
    DWORD type,                 /* Either REG_DWORD or REG_DWORD_BIG_ENDIAN */
    DWORD value)                /* The value to be converted. */
{
    DWORD order = 1;
    DWORD localType;

    /*
     * Check to see if the low bit is in the first byte.
     */

    localType = (*((char*)(&order)) == 1) ? REG_DWORD : REG_DWORD_BIG_ENDIAN;
    return (type != localType) ? SWAPLONG(value) : value;
}

/* End of tclwinreg.c */