NAME
    Win32::TieRegistry - Manipulate the Win32 Registry

SYNOPSIS
      use Win32::TieRegistry 0.20 ( UseOptionName=>UseOptionValue[,...] );

      $Registry->SomeMethodCall(arg1,...);

      $subKey= $Registry->{"Key\\SubKey\\"};
      $valueData= $Registry->{"Key\\SubKey\\\\ValueName"};
      $Registry->{"Key\\SubKey\\"}= { "NewSubKey" => {...} };
      $Registry->{"Key\\SubKey\\\\ValueName"}= "NewValueData";
      $Registry->{"\\ValueName"}= [ pack("fmt",$data), REG_DATATYPE ];

EXAMPLES
      use Win32::TieRegistry( Delimiter=>"#", ArrayValues=>0 );
      $pound= $Registry->Delimiter("/");
      $diskKey= $Registry->{"LMachine/System/Disk/"}
        or  die "Can't read LMachine/System/Disk key: $^E\n";
      $data= $key->{"/Information"}
        or  die "Can't read LMachine/System/Disk//Information value: $^E\n";
      $remoteKey= $Registry->{"//ServerA/LMachine/System/"}
        or  die "Can't read //ServerA/LMachine/System/ key: $^E\n";
      $remoteData= $remoteKey->{"Disk//Information"}
        or  die "Can't read ServerA's System/Disk//Information value: $^E\n";
      foreach $entry (  keys(%$diskKey)  ) {
          ...
      }
      foreach $subKey (  $diskKey->SubKeyNames  ) {
          ...
      }
      $diskKey->AllowSave( 1 );
      $diskKey->RegSaveKey( "C:/TEMP/DiskReg", [] );

DESCRIPTION
    The *Win32::TieRegistry* module lets you manipulate the Registry via
    objects [as in "object oriented"] or via tied hashes. But you will
    probably mostly use a combination reference, that is, a reference to a
    tied hash that has also been made an object so that you can mix both
    access methods [as shown above].

    If you did not get this module as part of libwin32, you might want to
    get a recent version of libwin32 from CPAN which should include this
    module and the *Win32API::Registry* module that it uses.

    Skip to the SUMMARY section if you just want to dive in and start using
    the Registry from Perl.

    Accessing and manipulating the registry is extremely simple using
    *Win32::TieRegistry*. A single, simple expression can return you almost
    any bit of information stored in the Registry. *Win32::TieRegistry* also
    gives you full access to the "raw" underlying API calls so that you can
    do anything with the Registry in Perl that you could do in C. But the
    "simple" interface has been carefully designed to handle almost all
    operations itself without imposing arbitrary limits while providing
    sensible defaults so you can list only the parameters you care about.

    But first, an overview of the Registry itself.

  The Registry
    The Registry is a forest: a collection of several tree structures. The
    root of each tree is a key. These root keys are identified by predefined
    constants whose names start with "HKEY_". Although all keys have a few
    attributes associated with each [a class, a time stamp, and security
    information], the most important aspect of keys is that each can contain
    subkeys and can contain values.

    Each subkey has a name: a string which cannot be blank and cannot
    contain the delimiter character [backslash: '\\'] nor nul ['\0']. Each
    subkey is also a key and so can contain subkeys and values [and has a
    class, time stamp, and security information].

    Each value has a name: a string which can be blank and can contain the
    delimiter character [backslash: '\\'] and any character except for null,
    '\0'. Each value also has data associated with it. Each value's data is
    a contiguous chunk of bytes, which is exactly what a Perl string value
    is so Perl strings will usually be used to represent value data.

    Each value also has a data type which says how to interpret the value
    data. The primary data types are:

    REG_SZ
        A null-terminated string.

    REG_EXPAND_SZ
        A null-terminated string which contains substrings consisting of a
        percent sign ['%'], an environment variable name, then a percent
        sign, that should be replaced with the value associate with that
        environment variable. The system does *not* automatically do this
        substitution.

    REG_BINARY
        Some arbitrary binary value. You can think of these as being
        "packed" into a string.

        If your system has the SetDualVar module installed, the
        "DualBinVals()" option wasn't turned off, and you fetch a
        "REG_BINARY" value of 4 bytes or fewer, then you can use the
        returned value in a numeric context to get at the "unpacked" numeric
        value. See "GetValue()" for more information.

    REG_MULTI_SZ
        Several null-terminated strings concatenated together with an extra
        trailing '\0' at the end of the list. Note that the list can include
        empty strings so use the value's length to determine the end of the
        list, not the first occurrence of '\0\0'. It is best to set the
        "SplitMultis()" option so *Win32::TieRegistry* will split these
        values into an array of strings for you.

    REG_DWORD
        A long [4-byte] integer value. These values are expected either
        packed into a 4-character string or as a hex string of more than 4
        characters [but *not* as a numeric value, unfortunately, as there is
        no sure way to tell a numeric value from a packed 4-byte string that
        just happens to be a string containing a valid numeric value].

        How such values are returned depends on the "DualBinVals()" and
        "DWordsToHex()" options. See "GetValue()" for details.

    In the underlying Registry calls, most places which take a subkey name
    also allow you to pass in a subkey "path" -- a string of several subkey
    names separated by the delimiter character, backslash ['\\']. For
    example, doing "RegOpenKeyEx(HKEY_LOCAL_MACHINE,"SYSTEM\\DISK",...)" is
    much like opening the "SYSTEM" subkey of "HKEY_LOCAL_MACHINE", then
    opening its "DISK" subkey, then closing the "SYSTEM" subkey.

    All of the *Win32::TieRegistry* features allow you to use your own
    delimiter in place of the system's delimiter, ['\\']. In most of our
    examples we will use a forward slash ['/'] as our delimiter as it is
    easier to read and less error prone to use when writing Perl code since
    you have to type two backslashes for each backslash you want in a
    string. Note that this is true even when using single quotes --
    '\\HostName\LMachine\' is an invalid string and must be written as
    '\\\\HostName\\LMachine\\'.

    You can also connect to the registry of other computers on your network.
    This will be discussed more later.

    Although the Registry does not have a single root key, the
    *Win32::TieRegistry* module creates a virtual root key for you which has
    all of the *HKEY_** keys as subkeys.

  Tied Hashes Documentation
    Before you can use a tied hash, you must create one. One way to do that
    is via:

        use Win32::TieRegistry ( TiedHash => '%RegHash' );

    which exports a %RegHash variable into your package and ties it to the
    virtual root key of the Registry. An alternate method is:

        my %RegHash;
        use Win32::TieRegistry ( TiedHash => \%RegHash );

    There are also several ways you can tie a hash variable to any other key
    of the Registry, which are discussed later.

    Note that you will most likely use $Registry instead of using a tied
    hash. $Registry is a reference to a hash that has been tied to the
    virtual root of your computer's Registry [as if, "$Registry=
    \%RegHash"]. So you would use "$Registry->{Key}" rather than
    $RegHash{Key} and use "keys %{$Registry}" rather than "keys %RegHash",
    for example.

    For each hash which has been tied to a Registry key, the Perl "keys"
    function will return a list containing the name of each of the key's
    subkeys with a delimiter character appended to it and containing the
    name of each of the key's values with a delimiter prepended to it. For
    example:

        keys( %{ $Registry->{"HKEY_CLASSES_ROOT\\batfile\\"} } )

    might yield the following list value:

        ( "DefaultIcon\\",  # The subkey named "DefaultIcon"
          "shell\\",        # The subkey named "shell"
          "shellex\\",      # The subkey named "shellex"
          "\\",             # The default value [named ""]
          "\\EditFlags" )   # The value named "EditFlags"

    For the virtual root key, short-hand subkey names are used as shown
    below. You can use the short-hand name, the regular *HKEY_** name, or
    any numeric value to access these keys, but the short-hand names are all
    that will be returned by the "keys" function.

    "Classes" for HKEY_CLASSES_ROOT
        Contains mappings between file name extensions and the uses for such
        files along with configuration information for COM [MicroSoft's
        Common Object Model] objects. Usually a link to the
        "SOFTWARE\\Classes" subkey of the "HKEY_LOCAL_MACHINE" key.

    "CUser" for HKEY_CURRENT_USER
        Contains information specific to the currently logged-in user.
        Mostly software configuration information. Usually a link to a
        subkey of the "HKEY_USERS" key.

    "LMachine" for HKEY_LOCAL_MACHINE
        Contains all manner of information about the computer.

    "Users" for HKEY_USERS
        Contains one subkey, ".DEFAULT", which gets copied to a new subkey
        whenever a new user is added. Also contains a subkey for each user
        of the system, though only those for active users [usually only one]
        are loaded at any given time.

    "PerfData" for HKEY_PERFORMANCE_DATA
        Used to access data about system performance. Access via this key is
        "special" and all but the most carefully constructed calls will
        fail, usually with "ERROR_INSUFFICIENT_BUFFER". For example, you
        can't enumerate key names without also enumerating values which
        require huge buffers but the exact buffer size required cannot be
        determined beforehand because "RegQueryInfoKey()" always fails with
        "ERROR_INSUFFICIENT_BUFFER" for "HKEY_PERFORMANCE_DATA" no matter
        how it is called. So it is currently not very useful to tie a hash
        to this key. You can use it to create an object to use for making
        carefully constructed calls to the underlying Reg*() routines.

    "CConfig" for HKEY_CURRENT_CONFIG
        Contains minimal information about the computer's current
        configuration that is required very early in the boot process. For
        example, setting for the display adapter such as screen resolution
        and refresh rate are found in here.

    "DynData" for HKEY_DYN_DATA
        Dynamic data. We have found no documentation for this key.

    A tied hash is much like a regular hash variable in Perl -- you give it
    a key string inside braces, ["{" and "}"], and it gives you back a value
    [or lets you set a value]. For *Win32::TieRegistry* hashes, there are
    two types of values that will be returned.

    SubKeys
        If you give it a string which represents a subkey, then it will give
        you back a reference to a hash which has been tied to that subkey.
        It can't return the hash itself, so it returns a reference to it. It
        also blesses that reference so that it is also an object so you can
        use it to call method functions.

    Values
        If you give it a string which is a value name, then it will give you
        back a string which is the data for that value. Alternately, you can
        request that it give you both the data value string and the data
        value type [we discuss how to request this later]. In this case, it
        would return a reference to an array where the value data string is
        element "[0]" and the value data type is element "[1]".

    The key string which you use in the tied hash must be interpreted to
    determine whether it is a value name or a key name or a path that
    combines several of these or even other things. There are two simple
    rules that make this interpretation easy and unambiguous:

        Put a delimiter after each key name.
        Put a delimiter in front of each value name.

    Exactly how the key string will be intepreted is governed by the
    following cases, in the order listed. These cases are designed to "do
    what you mean". Most of the time you won't have to think about them,
    especially if you follow the two simple rules above. After the list of
    cases we give several examples which should be clear enough so feel free
    to skip to them unless you are worried about the details.

    Remote machines
        If the hash is tied to the virtual root of the registry [or the
        virtual root of a remote machine's registry], then we treat hash key
        strings which start with the delimiter character specially.

        If the hash key string starts with two delimiters in a row, then
        those should be immediately followed by the name of a remote machine
        whose registry we wish to connect to. That can be followed by a
        delimiter and more subkey names, etc. If the machine name is not
        following by anything, then a virtual root for the remote machine's
        registry is created, a hash is tied to it, and a reference to that
        hash it is returned.

    Hash key string starts with the delimiter
        If the hash is tied to a virtual root key, then the leading
        delimiter is ignored. It should be followed by a valid Registry root
        key name [either a short-hand name like "LMachine", an *HKEY_**
        value, or a numeric value]. This alternate notation is allowed in
        order to be more consistant with the "Open()" method function.

        For all other Registry keys, the leading delimiter indicates that
        the rest of the string is a value name. The leading delimiter is
        stripped and the rest of the string [which can be empty and can
        contain more delimiters] is used as a value name with no further
        parsing.

    Exact match with direct subkey name followed by delimiter
        If you have already called the Perl "keys" function on the tied hash
        [or have already called "MemberNames" on the object] and the hash
        key string exactly matches one of the strings returned, then no
        further parsing is done. In other words, if the key string exactly
        matches the name of a direct subkey with a delimiter appended, then
        a reference to a hash tied to that subkey is returned [but only if
        "keys" or "MemberNames" has already been called for that tied hash].

        This is only important if you have selected a delimiter other than
        the system default delimiter and one of the subkey names contains
        the delimiter you have chosen. This rule allows you to deal with
        subkeys which contain your chosen delimiter in their name as long as
        you only traverse subkeys one level at a time and always enumerate
        the list of members before doing so.

        The main advantage of this is that Perl code which recursively
        traverses a hash will work on hashes tied to Registry keys even if a
        non-default delimiter has been selected.

    Hash key string contains two delimiters in a row
        If the hash key string contains two [or more] delimiters in a row,
        then the string is split between the first pair of delimiters. The
        first part is interpreted as a subkey name or a path of subkey names
        separated by delimiters and with a trailing delimiter. The second
        part is interpreted as a value name with one leading delimiter [any
        extra delimiters are considered part of the value name].

    Hash key string ends with a delimiter
        If the key string ends with a delimiter, then it is treated as a
        subkey name or path of subkey names separated by delimiters.

    Hash key string contains a delimiter
        If the key string contains a delimiter, then it is split after the
        last delimiter. The first part is treated as a subkey name or path
        of subkey names separated by delimiters. The second part is
        ambiguous and is treated as outlined in the next item.

    Hash key string contains no delimiters
        If the hash key string contains no delimiters, then it is ambiguous.

        If you are reading from the hash [fetching], then we first use the
        key string as a value name. If there is a value with a matching name
        in the Registry key which the hash is tied to, then the value data
        string [and possibly the value data type] is returned. Otherwise, we
        retry by using the hash key string as a subkey name. If there is a
        subkey with a matching name, then we return a reference to a hash
        tied to that subkey. Otherwise we return "undef".

        If you are writing to the hash [storing], then we use the key string
        as a subkey name only if the value you are storing is a reference to
        a hash value. Otherwise we use the key string as a value name.

   Examples
    Here are some examples showing different ways of accessing Registry
    information using references to tied hashes:

    Canonical value fetch
            $tip18= $Registry->{"HKEY_LOCAL_MACHINE\\Software\\Microsoft\\"
                       . 'Windows\\CurrentVersion\\Explorer\\Tips\\\\18'};

        Should return the text of important tip number 18. Note that two
        backslashes, "\\", are required to get a single backslash into a
        Perl double-quoted or single-qouted string. Note that "\\" is
        appended to each key name ["HKEY_LOCAL_MACHINE" through "Tips"] and
        "\\" is prepended to the value name, "18".

    Changing your delimiter
            $Registry->Delimiter("/");
            $tip18= $Registry->{"HKEY_LOCAL_MACHINE/Software/Microsoft/"
                       . 'Windows/CurrentVersion/Explorer/Tips//18'};

        This usually makes things easier to read when working in Perl. All
        remaining examples will assume the delimiter has been changed as
        above.

    Using intermediate keys
            $ms= $Registry->{"LMachine/Software/Microsoft/"};
            $tips= $ms->{"Windows/CurrentVersion/Explorer/Tips/"};
            $tip18= $winlogon->{"/18"};

        Same as above but opens more keys into the Registry which lets you
        efficiently re-access those intermediate keys. This is slightly less
        efficient if you never reuse those intermediate keys.

    Chaining in a single statement
            $tip18= $Registry->{"LMachine/Software/Microsoft/"}->
                      {"Windows/CurrentVersion/Explorer/Tips/"}->{"/18"};

        Like above, this creates intermediate key objects then uses them to
        access other data. Once this statement finishes, the intermediate
        key objects are destroyed. Several handles into the Registry are
        opened and closed by this statement so it is less efficient but
        there are times when this will be useful.

    Even less efficient example of chaining
            $tip18= $Registry->{"LMachine/Software/Microsoft"}->
                      {"Windows/CurrentVersion/Explorer/Tips"}->{"/18"};

        Because we left off the trailing delimiters, *Win32::TieRegistry*
        doesn't know whether final names, "Microsoft" and "Tips", are subkey
        names or value names. So this statement ends up executing the same
        code as the next one.

    What the above really does
            $tip18= $Registry->{"LMachine/Software/"}->{"Microsoft"}->
                      {"Windows/CurrentVersion/Explorer/"}->{"Tips"}->{"/18"};

        With more chains to go through, more temporary objects are created
        and later destroyed than in our first chaining example. Also, when
        "Microsoft" is looked up, *Win32::TieRegistry* first tries to open
        it as a value and fails then tries it as a subkey. The same is true
        for when it looks up "Tips".

    Getting all of the tips
            $tips= $Registry->{"LMachine/Software/Microsoft/"}->
                      {"Windows/CurrentVersion/Explorer/Tips/"}
              or  die "Can't find the Windows tips: $^E\n";
            foreach(  keys %$tips  ) {
                print "$_: ", $tips->{$_}, "\n";
            }

        First notice that we actually check for failure for the first time.
        We are assuming that the "Tips" key contains no subkeys. Otherwise
        the "print" statement would show something like
        "Win32::TieRegistry=HASH(0xc03ebc)" for each subkey.

        The output from the above code will start something like:

            /0: If you don't know how to do something,[...]

   Deleting items
    You can use the Perl "delete" function to delete a value from a Registry
    key or to delete a subkey as long that subkey contains no subkeys of its
    own. See "More Examples", below, for more information.

   Storing items
    You can use the Perl assignment operator ["="] to create new keys,
    create new values, or replace values. The values you store should be in
    the same format as the values you would fetch from a tied hash. For
    example, you can use a single assignment statement to copy an entire
    Registry tree. The following statement:

        $Registry->{"LMachine/Software/Classes/Tie_Registry/"}=
          $Registry->{"LMachine/Software/Classes/batfile/"};

    creates a "Tie_Registry" subkey under the "Software\\Classes" subkey of
    the "HKEY_LOCAL_MACHINE" key. Then it populates it with copies of all of
    the subkeys and values in the "batfile" subkey and all of its subkeys.
    Note that you need to have called "$Registry->ArrayValues(1)" for the
    proper value data type information to be copied. Note also that this
    release of *Win32::TieRegistry* does not copy key attributes such as
    class name and security information [this is planned for a future
    release].

    The following statement creates a whole subtree in the Registry:

        $Registry->{"LMachine/Software/FooCorp/"}= {
            "FooWriter/" => {
                "/Version" => "4.032",
                "Startup/" => {
                    "/Title" => "Foo Writer Deluxe ][",
                    "/WindowSize" => [ pack("LL",$wid,$ht), "REG_BINARY" ],
                    "/TaskBarIcon" => [ "0x0001", "REG_DWORD" ],
                },
                "Compatibility/" => {
                    "/AutoConvert" => "Always",
                    "/Default Palette" => "Windows Colors",
                },
            },
            "/License", => "0123-9C8EF1-09-FC",
        };

    Note that all but the last Registry key used on the left-hand side of
    the assignment [that is, "LMachine/Software/" but not "FooCorp/"] must
    already exist for this statement to succeed.

    By using the leading a trailing delimiters on each subkey name and value
    name, *Win32::TieRegistry* will tell you if you try to assign subkey
    information to a value or visa-versa.

   More examples
    Adding a new tip
            $tips= $Registry->{"LMachine/Software/Microsoft/"}->
                      {"Windows/CurrentVersion/Explorer/Tips/"}
              or  die "Can't find the Windows tips: $^E\n";
            $tips{'/186'}= "Be very careful when making changes to the Registry!";

    Deleting our new tip
            $tips= $Registry->{"LMachine/Software/Microsoft/"}->
                      {"Windows/CurrentVersion/Explorer/Tips/"}
              or  die "Can't find the Windows tips: $^E\n";
            $tip186= delete $tips{'/186'};

        Note that Perl's "delete" function returns the value that was
        deleted.

    Adding a new tip differently
            $Registry->{"LMachine/Software/Microsoft/" .
                        "Windows/CurrentVersion/Explorer/Tips//186"}=
              "Be very careful when making changes to the Registry!";

    Deleting differently
            $tip186= delete $Registry->{"LMachine/Software/Microsoft/Windows/" .
                                        "CurrentVersion/Explorer/Tips//186"};

        Note that this only deletes the tail of what we looked up, the "186"
        value, not any of the keys listed.

    Deleting a key
        WARNING: The following code will delete all information about the
        current user's tip preferences. Actually executing this command
        would probably cause the user to see the Welcome screen the next
        time they log in and may cause more serious problems. This statement
        is shown as an example only and should not be used when
        experimenting.

            $tips= delete $Registry->{"CUser/Software/Microsoft/Windows/" .
                                      "CurrentVersion/Explorer/Tips/"};

        This deletes the "Tips" key and the values it contains. The "delete"
        function will return a reference to a hash [not a tied hash]
        containing the value names and value data that were deleted.

        The information to be returned is copied from the Registry into a
        regular Perl hash before the key is deleted. If the key has many
        subkeys, this copying could take a significant amount of memory
        and/or processor time. So you can disable this process by calling
        the "FastDelete" member function:

            $prevSetting= $regKey->FastDelete(1);

        which will cause all subsequent delete operations via $regKey to
        simply return a true value if they succeed. This optimization is
        automatically done if you use "delete" in a void context.

    Technical notes on deleting
        If you use "delete" to delete a Registry key or value and use the
        return value, then *Win32::TieRegistry* usually looks up the current
        contents of that key or value so they can be returned if the
        deletion is successful. If the deletion succeeds but the attempt to
        lookup the old contents failed, then the return value of "delete"
        will be $^E from the failed part of the operation.

    Undeleting a key
            $Registry->{"LMachine/Software/Microsoft/Windows/" .
                        "CurrentVersion/Explorer/Tips/"}= $tips;

        This adds back what we just deleted. Note that this version of
        *Win32::TieRegistry* will use defaults for the key attributes [such
        as class name and security] and will not restore the previous
        attributes.

    Not deleting a key
        WARNING: Actually executing the following code could cause serious
        problems. This statement is shown as an example only and should not
        be used when experimenting.

            $res= delete $Registry->{"CUser/Software/Microsoft/Windows/"}
            defined($res)  ||  die "Can't delete URL key: $^E\n";

        Since the "Windows" key should contain subkeys, that "delete"
        statement should make no changes to the Registry, return "undef",
        and set $^E to "Access is denied".

    Not deleting again
            $tips= $Registry->{"CUser/Software/Microsoft/Windows/" .
                               "CurrentVersion/Explorer/Tips/"};
            delete $tips;

        The Perl "delete" function requires that its argument be an
        expression that ends in a hash element lookup [or hash slice], which
        is not the case here. The "delete" function doesn't know which hash
        $tips came from and so can't delete it.

  Objects Documentation
    The following member functions are defined for use on
    *Win32::TieRegistry* objects:

    new The "new" method creates a new *Win32::TieRegistry* object. "new" is
        mostly a synonym for "Open()" so see "Open()" below for information
        on what arguments to pass in. Examples:

            $machKey= new Win32::TieRegistry "LMachine"
              or  die "Can't access HKEY_LOCAL_MACHINE key: $^E\n";
            $userKey= Win32::TieRegistry->new("CUser")
              or  die "Can't access HKEY_CURRENT_USER key: $^E\n";

        Note that calling "new" via a reference to a tied hash returns a
        simple object, not a reference to a tied hash.

    Open
    $subKey= $key->Open( $sSubKey, $rhOptions )
        The "Open" method opens a Registry key and returns a new
        *Win32::TieRegistry* object associated with that Registry key. If
        "Open" is called via a reference to a tied hash, then "Open" returns
        another reference to a tied hash. Otherwise "Open" returns a simple
        object and you should then use "TiedRef" to get a reference to a
        tied hash.

        $sSubKey is a string specifying a subkey to be opened. Alternately
        $sSubKey can be a reference to an array value containing the list of
        increasingly deep subkeys specifying the path to the subkey to be
        opened.

        $rhOptions is an optional reference to a hash containing extra
        options. The "Open" method supports two options, "Delimiter" and
        "Access", and $rhOptions should have only have zero or more of these
        strings as keys. See the "Examples" section below for more
        information.

        The "Delimiter" option specifies what string [usually a single
        character] will be used as the delimiter to be appended to subkey
        names and prepended to value names. If this option is not specified,
        the new key [$subKey] inherits the delimiter of the old key [$key].

        The "Access" option specifies what level of access to the Registry
        key you wish to have once it has been opened. If this option is not
        specified, the new key [$subKey] is opened with the same access
        level used when the old key [$key] was opened. The virtual root of
        the Registry pretends it was opened with access
        "KEY_READ()|KEY_WRITE()" so this is the default access when opening
        keys directory via $Registry. If you don't plan on modifying a key,
        you should open it with "KEY_READ" access as you may not have
        "KEY_WRITE" access to it or some of its subkeys.

        If the "Access" option value is a string that starts with "KEY_",
        then it should match one of the predefined access levels [probably
        "KEY_READ", "KEY_WRITE", or "KEY_ALL_ACCESS"] exported by the
        *Win32API::Registry* module. Otherwise, a numeric value is expected.
        For maximum flexibility, include "use Win32::TieRegistry
        qw(:KEY_);", for example, near the top of your script so you can
        specify more complicated access levels such as
        "KEY_READ()|KEY_WRITE()".

        If $sSubKey does not begin with the delimiter [or $sSubKey is an
        array reference], then the path to the subkey to be opened will be
        relative to the path of the original key [$key]. If $sSubKey begins
        with a single delimiter, then the path to the subkey to be opened
        will be relative to the virtual root of the Registry on whichever
        machine the original key resides. If $sSubKey begins with two
        consectutive delimiters, then those must be followed by a machine
        name which causes the "Connect()" method function to be called.

        Examples:

            $machKey= $Registry->Open( "LMachine", {Access=>KEY_READ(),Delimiter=>"/"} )
              or  die "Can't open HKEY_LOCAL_MACHINE key: $^E\n";
            $swKey= $machKey->Open( "Software" );
            $logonKey= $swKey->Open( "Microsoft/Windows NT/CurrentVersion/Winlogon/" );
            $NTversKey= $swKey->Open( ["Microsoft","Windows NT","CurrentVersion"] );
            $versKey= $swKey->Open( qw(Microsoft Windows CurrentVersion) );

            $remoteKey= $Registry->Open( "//HostA/LMachine/System/", {Delimiter=>"/"} )
              or  die "Can't connect to HostA or can't open subkey: $^E\n";

    Clone
    $copy= $key->Clone
        Creates a new object that is associated with the same Registry key
        as the invoking object.

    Connect
    $remoteKey= $Registry->Connect( $sMachineName, $sKeyPath, $rhOptions )
        The "Connect" method connects to the Registry of a remote machine,
        and opens a key within it, then returns a new *Win32::TieRegistry*
        object associated with that remote Registry key. If "Connect" was
        called using a reference to a tied hash, then the return value will
        also be a reference to a tied hash [or "undef"]. Otherwise, if you
        wish to use the returned object as a tied hash [not just as an
        object], then use the "TiedRef" method function after "Connect".

        $sMachineName is the name of the remote machine. You don't have to
        preceed the machine name with two delimiter characters.

        $sKeyPath is a string specifying the remote key to be opened.
        Alternately $sKeyPath can be a reference to an array value
        containing the list of increasingly deep keys specifying the path to
        the key to be opened.

        $rhOptions is an optional reference to a hash containing extra
        options. The "Connect" method supports two options, "Delimiter" and
        "Access". See the "Open" method documentation for more information
        on these options.

        $sKeyPath is already relative to the virtual root of the Registry of
        the remote machine. A single leading delimiter on "sKeyPath" will be
        ignored and is not required.

        $sKeyPath can be empty in which case "Connect" will return an object
        representing the virtual root key of the remote Registry. Each
        subsequent use of "Open" on this virtual root key will call the
        system "RegConnectRegistry" function.

        The "Connect" method can be called via any *Win32::TieRegistry*
        object, not just $Registry. Attributes such as the desired level of
        access and the delimiter will be inherited from the object used but
        the $sKeyPath will always be relative to the virtual root of the
        remote machine's registry.

        Examples:

            $remMachKey= $Registry->Connect( "HostA", "LMachine", {Delimiter->"/"} )
              or  die "Can't connect to HostA's HKEY_LOCAL_MACHINE key: $^E\n";

            $remVersKey= $remMachKey->Connect( "www.microsoft.com",
                           "LMachine/Software/Microsoft/Inetsrv/CurrentVersion/",
                           { Access=>KEY_READ, Delimiter=>"/" } )
              or  die "Can't check what version of IIS Microsoft is running: $^E\n";

            $remVersKey= $remMachKey->Connect( "www",
                           qw(LMachine Software Microsoft Inetsrv CurrentVersion) )
              or  die "Can't check what version of IIS we are running: $^E\n";

    ObjectRef
    $object_ref= $obj_or_hash_ref->ObjectRef
        For a simple object, just returns itself ["$obj ==
        $obj-"ObjectRef>].

        For a reference to a tied hash [if it is also an object],
        "ObjectRef" returns the simple object that the hash is tied to.

        This is primarilly useful when debugging since typing "x $Registry"
        will try to display your *entire* registry contents to your screen.
        But the debugger command "x $Registry-"ObjectRef> will just dump the
        implementation details of the underlying object to your screen.

    Flush( $bFlush )
        Flushes all cached information about the Registry key so that future
        uses will get fresh data from the Registry.

        If the optional $bFlush is specified and a true value, then
        "RegFlushKey()" will be called, which is almost never necessary.

    GetValue
    $ValueData= $key->GetValue( $sValueName )
    ($ValueData,$ValueType)= $key->GetValue( $sValueName )
        Gets a Registry value's data and data type.

        $ValueData is usually just a Perl string that contains the value
        data [packed into it]. For certain types of data, however,
        $ValueData may be processed as described below.

        $ValueType is the "REG_*" constant describing the type of value data
        stored in $ValueData. If the "DualTypes()" option is on, then
        $ValueType will be a dual value. That is, when used in a numeric
        context, $ValueType will give the numeric value of a "REG_*"
        constant. However, when used in a non-numeric context, $ValueType
        will return the name of the "REG_*" constant, for example "REG_SZ"
        [note the quotes]. So both of the following can be true at the same
        time:

            $ValueType == REG_SZ()
            $ValueType eq "REG_SZ"

        REG_SZ and REG_EXPAND_SZ
            If the "FixSzNulls()" option is on, then the trailing '\0' will
            be stripped [unless there isn't one] before values of type
            "REG_SZ" and "REG_EXPAND_SZ" are returned. Note that
            "SetValue()" will add a trailing '\0' under similar
            circumstances.

        REG_MULTI_SZ
            If the "SplitMultis()" option is on, then values of this type
            are returned as a reference to an array containing the strings.
            For example, a value that, with "SplitMultis()" off, would be
            returned as:

                "Value1\000Value2\000\000"

            would be returned, with "SplitMultis()" on, as:

                [ "Value1", "Value2" ]

        REG_DWORD
            If the "DualBinVals()" option is on, then the value is returned
            as a scalar containing both a string and a number [much like the
            $! variable -- see the SetDualVar module for more information]
            where the number part is the "unpacked" value. Use the returned
            value in a numeric context to access this part of the value. For
            example:

                $num= 0 + $Registry->{"CUser/Console//ColorTable01"};

            If the "DWordsToHex()" option is off, the string part of the
            returned value is a packed, 4-byte string [use
            "unpack("L",$value)" to get the numeric value.

            If "DWordsToHex()" is on, the string part of the returned value
            is a 10-character hex strings [with leading "0x"]. You can use
            "hex($value)" to get the numeric value.

            Note that "SetValue()" will properly understand each of these
            returned value formats no matter how "DualBinVals()" is set.

    ValueNames
    @names= $key->ValueNames
        Returns the list of value names stored directly in a Registry key.
        Note that the names returned do *not* have a delimiter prepended to
        them like with "MemberNames()" and tied hashes.

        Once you request this information, it is cached in the object and
        future requests will always return the same list unless "Flush()"
        has been called.

    SubKeyNames
    @key_names= $key->SubKeyNames
        Returns the list of subkey names stored directly in a Registry key.
        Note that the names returned do *not* have a delimiter appended to
        them like with "MemberNames()" and tied hashes.

        Once you request this information, it is cached in the object and
        future requests will always return the same list unless "Flush()"
        has been called.

    SubKeyClasses
    @classes= $key->SubKeyClasses
        Returns the list of classes for subkeys stored directly in a
        Registry key. The classes are returned in the same order as the
        subkey names returned by "SubKeyNames()".

    SubKeyTimes
    @times= $key->SubKeyTimes
        Returns the list of last-modified times for subkeys stored directly
        in a Registry key. The times are returned in the same order as the
        subkey names returned by "SubKeyNames()". Each time is a "FILETIME"
        structure packed into a Perl string.

        Once you request this information, it is cached in the object and
        future requests will always return the same list unless "Flush()"
        has been called.

    MemberNames
    @members= $key->MemberNames
        Returns the list of subkey names and value names stored directly in
        a Registry key. Subkey names have a delimiter appended to the end
        and value names have a delimiter prepended to the front.

        Note that a value name could end in a delimiter [or could be "" so
        that the member name returned is just a delimiter] so the presence
        or absence of the leading delimiter is what should be used to
        determine whether a particular name is for a subkey or a value, not
        the presence or absence of a trailing delimiter.

        Once you request this information, it is cached in the object and
        future requests will always return the same list unless "Flush()"
        has been called.

    Information
    %info= $key->Information
    @items= $key->Information( @itemNames );
        Returns the following information about a Registry key:

        LastWrite
            A "FILETIME" structure indicating when the key was last modified
            and packed into a Perl string.

        CntSubKeys
            The number of subkeys stored directly in this key.

        CntValues
            The number of values stored directly in this key.

        SecurityLen
            The length [in bytes] of the largest[?] "SECURITY_DESCRIPTOR"
            associated with the Registry key.

        MaxValDataLen
            The length [in bytes] of the longest value data associated with
            a value stored in this key.

        MaxSubKeyLen
            The length [in chars] of the longest subkey name associated with
            a subkey stored in this key.

        MaxSubClassLen
            The length [in chars] of the longest class name associated with
            a subkey stored directly in this key.

        MaxValNameLen
            The length [in chars] of the longest value name associated with
            a value stored in this key.

        With no arguments, returns a hash [not a reference to a hash] where
        the keys are the names for the items given above and the values are
        the information describe above. For example:

            %info= ( "CntValues" => 25,         # Key contains 25 values.
                     "MaxValNameLen" => 20,     # One of which has a 20-char name.
                     "MaxValDataLen" => 42,     # One of which has a 42-byte value.
                     "CntSubKeys" => 1,         # Key has 1 immediate subkey.
                     "MaxSubKeyLen" => 13,      # One of which has a 12-char name.
                     "MaxSubClassLen" => 0,     # All of which have class names of "".
                     "SecurityLen" => 232,      # One SECURITY_DESCRIPTOR is 232 bytes.
                     "LastWrite" => "\x90mZ\cX{\xA3\xBD\cA\c@\cA"
                                   # Key was last modifed 1998/06/01 16:29:32 GMT
                   );

        With arguments, each one must be the name of a item given above. The
        return value is the information associated with the listed names. In
        other words:

            return $key->Information( @names );

        returns the same list as:

            %info= $key->Information;
            return @info{@names};

    Delimiter
    $oldDelim= $key->Delimiter
    $oldDelim= $key->Delimiter( $newDelim )
        Gets and possibly changes the delimiter used for this object. The
        delimiter is appended to subkey names and prepended to value names
        in many return values. It is also used when parsing keys passed to
        tied hashes.

        The delimiter defaults to backslash ('\\') but is inherited from the
        object used to create a new object and can be specified by an option
        when a new object is created.

    Handle
    $handle= $key->Handle
        Returns the raw "HKEY" handle for the associated Registry key as an
        integer value. This value can then be used to Reg*() calls from
        *Win32API::Registry*. However, it is usually easier to just call the
        *Win32API::Registry* calls directly via:

            $key->RegNotifyChangeKeyValue( ... );

        For the virtual root of the local or a remote Registry, "Handle()"
        return "NONE".

    Path
    $path= $key->Path
        Returns a string describing the path of key names to this Registry
        key. The string is built so that if it were passed to
        "$Registry-"Open()>, it would reopen the same Registry key [except
        in the rare case where one of the key names contains
        "$key-"Delimiter>].

    Machine
    $computerName= $key->Machine
        Returns the name of the computer [or "machine"] on which this
        Registry key resides. Returns "" for local Registry keys.

    Access
        Returns the numeric value of the bit mask used to specify the types
        of access requested when this Registry key was opened. Can be
        compared to "KEY_*" values.

    OS_Delimiter
        Returns the delimiter used by the operating system's RegOpenKeyEx()
        call. For Win32, this is always backslash ("\\").

    Roots
        Returns the mapping from root key names like "LMachine" to their
        associated "HKEY_*" constants. Primarily for internal use and
        subject to change.

    Tie
    $key->Tie( \%hash );
        Ties the referenced hash to that Registry key. Pretty much the same
        as

            tie %hash, ref($key), $key;

        Since "ref($key)" is the class [package] to tie the hash to and
        "TIEHASH()" just returns its argument, $key, [without calling
        "new()"] when it sees that it is already a blessed object.

    TiedRef
    $TiedHashRef= $hash_or_obj_ref->TiedRef
        For a simple object, returns a reference to a hash tied to the
        object. Used to promote a simple object into a combined object and
        hash ref.

        If already a reference to a tied hash [that is also an object], it
        just returns itself ["$ref == $ref-"TiedRef>].

        Mostly used internally.

    ArrayValues
    $oldBool= $key->ArrayValues
    $oldBool= $key->ArrayValues( $newBool )
        Gets the current setting of the "ArrayValues" option and possibly
        turns it on or off.

        When off, Registry values fetched via a tied hash are returned as
        just a value scalar [the same as "GetValue()" in a scalar context].
        When on, they are returned as a reference to an array containing the
        value data as the "[0]" element and the data type as the "[1]"
        element.

    TieValues
    $oldBool= TieValues
    $oldBool= TieValues( $newBool )
        Gets the current setting of the "TieValues" option and possibly
        turns it on or off.

        Turning this option on is not yet supported in this release of
        *Win32::TieRegistry*. In a future release, turning this option on
        will cause Registry values returned from a tied hash to be a tied
        array that you can use to modify the value in the Registry.

    FastDelete
    $oldBool= $key->FastDelete
    $oldBool= $key->FastDelete( $newBool )
        Gets the current setting of the "FastDelete" option and possibly
        turns it on or off.

        When on, successfully deleting a Registry key [via a tied hash]
        simply returns 1.

        When off, successfully deleting a Registry key [via a tied hash and
        not in a void context] returns a reference to a hash that contains
        the values present in the key when it was deleted. This hash is just
        like that returned when referencing the key before it was deleted
        except that it is an ordinary hash, not one tied to the
        *Win32::TieRegistry* package.

        Note that deleting either a Registry key or value via a tied hash
        *in a void context* prevents any overhead in trying to build an
        appropriate return value.

        Note that deleting a Registry *value* via a tied hash [not in a void
        context] returns the value data even if <FastDelete> is on.

    SplitMultis
    $oldBool= $key->SplitMultis
    $oldBool= $key->SplitMultis( $newBool )
        Gets the current setting of the "SplitMultis" option and possibly
        turns it on or off.

        If on, Registry values of type "REG_MULTI_SZ" are returned as a
        reference to an array of strings. See "GetValue()" for more
        information.

    DWordsToHex
    $oldBool= $key->DWordsToHex
    $oldBool= $key->DWordsToHex( $newBool )
        Gets the current setting of the "DWordsToHex" option and possibly
        turns it on or off.

        If on, Registry values of type "REG_DWORD" are returned as a hex
        string with leading "0x" and longer than 4 characters. See
        "GetValue()" for more information.

    FixSzNulls
    $oldBool= $key->FixSzNulls
    $oldBool= $key->FixSzNulls( $newBool )
        Gets the current setting of the "FixSzNulls" option and possibly
        turns it on or off.

        If on, Registry values of type "REG_SZ" and "REG_EXPAND_SZ" have
        trailing '\0's added before they are set and stripped before they
        are returned. See "GetValue()" and "SetValue()" for more
        information.

    DualTypes
    $oldBool= $key->DualTypes
    $oldBool= $key->DualTypes( $newBool )
        Gets the current setting of the "DualTypes" option and possibly
        turns it on or off.

        If on, data types are returned as a combined numeric/string value
        holding both the numeric value of a "REG_*" constant and the string
        value of the constant's name. See "GetValue()" for more information.

    DualBinVals
    $oldBool= $key->DualBinVals
    $oldBool= $key->DualBinVals( $newBool )
        Gets the current setting of the "DualBinVals" option and possibly
        turns it on or off.

        If on, Registry value data of type "REG_BINARY" and no more than 4
        bytes long and Registry values of type "REG_DWORD" are returned as a
        combined numeric/string value where the numeric value is the
        "unpacked" binary value as returned by:

                hex reverse unpack( "h*", $valData )

        on a "little-endian" computer. [Would be "hex unpack("H*",$valData)"
        on a "big-endian" computer if this module is ever ported to one.]

        See "GetValue()" for more information.

    GetOptions
    @oldOptValues= $key->GetOptions( @optionNames )
    $refHashOfOldOpts= $key->GetOptions()
    $key->GetOptions( \%hashForOldOpts )
        Returns the current setting of any of the following options:

            Delimiter     FixSzNulls    DWordsToHex
            ArrayValues   SplitMultis   DualBinVals
            TieValues     FastDelete    DualTypes

        Pass in one or more of the above names (as strings) to get back an
        array of the corresponding current settings in the same order:

          my( $fastDel, $delim )= $key->GetOptions("FastDelete","Delimiter");

        Pass in no arguments to get back a reference to a hash where the
        above option names are the keys and the values are the corresponding
        current settings for each option:

          my $href= $key->GetOptions();
          my $delim= $href->{Delimiter};

        Pass in a single reference to a hash to have the above key/value
        pairs *added* to the referenced hash. For this case, the return
        value is the original object so further methods can be chained after
        the call to GetOptions:

          my %oldOpts;
          $key->GetOptions( \%oldOpts )->SetOptions( Delimiter => "/" );

    SetOptions
    @oldOpts= $key->SetOptions( optNames=>$optValue,... )
        Changes the current setting of any of the following options,
        returning the previous setting(s):

            Delimiter     FixSzNulls    DWordsToHex   AllowLoad
            ArrayValues   SplitMultis   DualBinVals   AllowSave
            TieValues     FastDelete    DualTypes

        For "AllowLoad" and "AllowSave", instead of the previous setting,
        "SetOptions" returns whether or not the change was successful.

        In a scalar context, returns only the last item. The last option can
        also be specified as "ref" or "r" [which doesn't need to be followed
        by a value] to allow chaining:

            $key->SetOptions(AllowSave=>1,"ref")->RegSaveKey(...)

    SetValue
    $okay= $key->SetValue( $ValueName, $ValueData );
    $okay= $key->SetValue( $ValueName, $ValueData, $ValueType );
        Adds or replaces a Registry value. Returns a true value if
        successfully, false otherwise.

        $ValueName is the name of the value to add or replace and should
        *not* have a delimiter prepended to it. Case is ignored.

        $ValueType is assumed to be "REG_SZ" if it is omitted. Otherwise, it
        should be one the "REG_*" constants.

        $ValueData is the data to be stored in the value, probably packed
        into a Perl string. Other supported formats for value data are
        listed below for each posible $ValueType.

        REG_SZ or REG_EXPAND_SZ
            The only special processing for these values is the addition of
            the required trailing '\0' if it is missing. This can be turned
            off by disabling the "FixSzNulls" option.

        REG_MULTI_SZ
            These values can also be specified as a reference to a list of
            strings. For example, the following two lines are equivalent:

                $key->SetValue( "Val1\000Value2\000LastVal\000\000", "REG_MULTI_SZ" );
                $key->SetValue( ["Val1","Value2","LastVal"], "REG_MULTI_SZ" );

            Note that if the required two trailing nulls ("\000\000") are
            missing, then this release of "SetValue()" will *not* add them.

        REG_DWORD
            These values can also be specified as a hex value with the
            leading "0x" included and totaling *more than* 4 bytes. These
            will be packed into a 4-byte string via:

                $data= pack( "L", hex($data) );

        REG_BINARY
            This value type is listed just to emphasize that no alternate
            format is supported for it. In particular, you should *not* pass
            in a numeric value for this type of data. "SetValue()" cannot
            distinguish such from a packed string that just happens to match
            a numeric value and so will treat it as a packed string.

        An alternate calling format:

            $okay= $key->SetValue( $ValueName, [ $ValueData, $ValueType ] );

        [two arguments, the second of which is a reference to an array
        containing the value data and value type] is supported to ease using
        tied hashes with "SetValue()".

    CreateKey
    $newKey= $key->CreateKey( $subKey );
    $newKey= $key->CreateKey( $subKey, { Option=>OptVal,... } );
        Creates a Registry key or just updates attributes of one. Calls
        "RegCreateKeyEx()" then, if it succeeded, creates an object
        associated with the [possibly new] subkey.

        $subKey is the name of a subkey [or a path to one] to be created or
        updated. It can also be a reference to an array containing a list of
        subkey names.

        The second argument, if it exists, should be a reference to a hash
        specifying options either to be passed to "RegCreateKeyEx()" or to
        be used when creating the associated object. The following items are
        the supported keys for this options hash:

        Delimiter
            Specifies the delimiter to be used to parse $subKey and to be
            used in the new object. Defaults to "$key-"Delimiter>.

        Access
            Specifies the types of access requested when the subkey is
            opened. Should be a numeric bit mask that combines one or more
            "KEY_*" constant values.

        Class
            The name to assign as the class of the new or updated subkey.
            Defaults to "" as we have never seen a use for this information.

        Disposition
            Lets you specify a reference to a scalar where, upon success,
            will be stored either "REG_CREATED_NEW_KEY()" or
            "REG_OPENED_EXISTING_KEY()" depending on whether a new key was
            created or an existing key was opened.

            If you, for example, did "use Win32::TieRegistry
            qw(REG_CREATED_NEW_KEY)" then you can use
            "REG_CREATED_NEW_KEY()" to compare against the numeric value
            stored in the referenced scalar.

            If the "DualTypes" option is enabled, then in addition to the
            numeric value described above, the referenced scalar will also
            have a string value equal to either "REG_CREATED_NEW_KEY" or
            "REG_OPENED_EXISTING_KEY", as appropriate.

        Security
            Lets you specify a "SECURITY_ATTRIBUTES" structure packed into a
            Perl string. See "Win32API::Registry::RegCreateKeyEx()" for more
            information.

        Volatile
            If true, specifies that the new key should be volatile, that is,
            stored only in memory and not backed by a hive file [and not
            saved if the computer is rebooted]. This option is ignored under
            Windows 95. Specifying "Volatile=>1" is the same as specifying
            "Options=>REG_OPTION_VOLATILE".

        Backup
            If true, specifies that the new key should be opened for
            backup/restore access. The "Access" option is ignored. If the
            calling process has enabled "SeBackupPrivilege", then the subkey
            is opened with "KEY_READ" access as the "LocalSystem" user which
            should have access to all subkeys. If the calling process has
            enabled "SeRestorePrivilege", then the subkey is opened with
            "KEY_WRITE" access as the "LocalSystem" user which should have
            access to all subkeys.

            This option is ignored under Windows 95. Specifying "Backup=>1"
            is the same as specifying "Options=>REG_OPTION_BACKUP_RESTORE".

        Options
            Lets you specify options to the "RegOpenKeyEx()" call. The value
            for this option should be a numeric value combining zero or more
            of the "REG_OPTION_*" bit masks. You may with to used the
            "Volatile" and/or "Backup" options instead of this one.

    StoreKey
    $newKey= $key->StoreKey( $subKey, \%Contents );
        Primarily for internal use.

        Used to create or update a Registry key and any number of subkeys or
        values under it or its subkeys.

        $subKey is the name of a subkey to be created [or a path of subkey
        names separated by delimiters]. If that subkey already exists, then
        it is updated.

        "\%Contents" is a reference to a hash containing pairs of value
        names with value data and/or subkey names with hash references
        similar to "\%Contents". Each of these cause a value or subkey of
        $subKey to be created or updated.

        If $Contents{""} exists and is a reference to a hash, then it used
        as the options argument when "CreateKey()" is called for $subKey.
        This allows you to specify ...

            if(  defined( $$data{""} )  &&  "HASH" eq ref($$data{""})  ) {
                $self= $this->CreateKey( $subKey, delete $$data{""} );

    Load
    $newKey= $key->Load( $file )
    $newKey= $key->Load( $file, $newSubKey )
    $newKey= $key->Load( $file, $newSubKey, { Option=>OptVal... } )
    $newKey= $key->Load( $file, { Option=>OptVal... } )
        Loads a hive file into a Registry. That is, creates a new subkey and
        associates a hive file with it.

        $file is a hive file, that is a file created by calling
        "RegSaveKey()". The $file path is interpreted relative to
        "%SystemRoot%/System32/config" on the machine where $key resides.

        $newSubKey is the name to be given to the new subkey. If $newSubKey
        is specified, then $key must be "HKEY_LOCAL_MACHINE" or "HKEY_USERS"
        of the local computer or a remote computer and $newSubKey should not
        contain any occurrences of either the delimiter or the OS delimiter.

        If $newSubKey is not specified, then it is as if $key was
        "$Registry->{LMachine}" and $newSubKey is "PerlTie:999" where "999"
        is actually a sequence number incremented each time this process
        calls "Load()".

        You can specify as the last argument a reference to a hash
        containing options. You can specify the same options that you can
        specify to "Open()". See "Open()" for more information on those. In
        addition, you can specify the option "NewSubKey". The value of this
        option is interpretted exactly as if it was specified as the
        $newSubKey parameter and overrides the $newSubKey if one was
        specified.

        The hive is automatically unloaded when the returned object
        [$newKey] is destroyed. Registry key objects opened within the hive
        will keep a reference to the $newKey object so that it will not be
        destroyed before these keys are closed.

    UnLoad
    $okay= $key->UnLoad
        Unloads a hive that was loaded via "Load()". Cannot unload other
        hives. $key must be the return from a previous call to "Load()".
        $key is closed and then the hive is unloaded.

    AllowSave
    $okay= AllowSave( $bool )
        Enables or disables the "ReBackupPrivilege" privilege for the
        current process. You will probably have to enable this privilege
        before you can use "RegSaveKey()".

        The return value indicates whether the operation succeeded, not
        whether the privilege was previously enabled.

    AllowLoad
    $okay= AllowLoad( $bool )
        Enables or disables the "ReRestorePrivilege" privilege for the
        current process. You will probably have to enable this privilege
        before you can use "RegLoadKey()", "RegUnLoadKey()",
        "RegReplaceKey()", or "RegRestoreKey" and thus "Load()" and
        "UnLoad()".

        The return value indicates whether the operation succeeded, not
        whether the privilege was previously enabled.

  Exports ["use" and "import()"]
    To have nothing imported into your package, use something like:

        use Win32::TieRegistry 0.20 ();

    which would verify that you have at least version 0.20 but wouldn't call
    "import()". The Changes file can be useful in figuring out which, if
    any, prior versions of *Win32::TieRegistry* you want to support in your
    script.

    The code

        use Win32::TieRegistry;

    imports the variable $Registry into your package and sets it to be a
    reference to a hash tied to a copy of the master Registry virtual root
    object with the default options. One disadvantage to this "default"
    usage is that Perl does not support checking the module version when you
    use it.

    Alternately, you can specify a list of arguments on the "use" line that
    will be passed to the "Win32::TieRegistry-"import()> method to control
    what items to import into your package. These arguments fall into the
    following broad categories:

    Import a reference to a hash tied to a Registry virtual root
        You can request that a scalar variable be imported (possibly) and
        set to be a reference to a hash tied to a Registry virtual root
        using any of the following types of arguments or argument pairs:

        "TiedRef", '$scalar'
        "TiedRef", '$pack::scalar'
        "TiedRef", 'scalar'
        "TiedRef", 'pack::scalar'
            All of the above import a scalar named $scalar into your package
            (or the package named "pack") and then sets it.

        '$scalar'
        '$pack::scalar'
            These are equivalent to the previous items to support a more
            traditional appearance to the list of exports. Note that the
            scalar name cannot be "RegObj" here.

        "TiedRef", \$scalar
        \$scalar
            These versions don't import anything but set the referenced
            $scalar.

    Import a hash tied to the Registry virtual root
        You can request that a hash variable be imported (possibly) and tied
        to a Registry virtual root using any of the following types of
        arguments or argument pairs:

        "TiedHash", '%hash'
        "TiedHash", '%pack::hash'
        "TiedHash", 'hash'
        "TiedHash", 'pack::hash'
            All of the above import a hash named %hash into your package (or
            the package named "pack") and then sets it.

        '%hash'
        '%pack::hash'
            These are equivalent to the previous items to support a more
            traditional appearance to the list of exports.

        "TiedHash", \%hash
        \%hash
            These versions don't import anything but set the referenced
            %hash.

    Import a Registry virtual root object
        You can request that a scalar variable be imported (possibly) and
        set to be a Registry virtual root object using any of the following
        types of arguments or argument pairs:

        "ObjectRef", '$scalar'
        "ObjectRef", '$pack::scalar'
        "ObjectRef", 'scalar'
        "ObjectRef", 'pack::scalar'
            All of the above import a scalar named $scalar into your package
            (or the package named "pack") and then sets it.

        '$RegObj'
            This is equivalent to the previous items for backward
            compatibility.

        "ObjectRef", \$scalar
            This version doesn't import anything but sets the referenced
            $scalar.

    Import constant(s) exported by *Win32API::Registry*
        You can list any constants that are exported by *Win32API::Registry*
        to have them imported into your package. These constants have names
        starting with "KEY_" or "REG_" (or even "HKEY_").

        You can also specify ":KEY_", ":REG_", and even ":HKEY_" to import a
        whole set of constants.

        See *Win32API::Registry* documentation for more information.

    Options
        You can list any option names that can be listed in the
        "SetOptions()" method call, each folowed by the value to use for
        that option. A Registry virtual root object is created, all of these
        options are set for it, then each variable to be imported/set is
        associated with this object.

        In addition, the following special options are supported:

        ExportLevel
            Whether to import variables into your package or some package
            that uses your package. Defaults to the value of
            $Exporter::ExportLevel and has the same meaning. See the
            Exporter module for more information.

        ExportTo
            The name of the package to import variables and constants into.
            Overrides *ExportLevel*.

   Specifying constants in your Perl code
    This module was written with a strong emphasis on the convenience of the
    module user. Therefore, most places where you can specify a constant
    like "REG_SZ()" also allow you to specify a string containing the name
    of the constant, "REG_SZ". This is convenient because you may not have
    imported that symbolic constant.

    Perl also emphasizes programmer convenience so the code "REG_SZ" can be
    used to mean "REG_SZ()" or "REG_SZ" or be illegal. Note that using
    &REG_SZ (as we've seen in much Win32 Perl code) is not a good idea since
    it passes the current @_ to the "constant()" routine of the module
    which, at the least, can give you a warning under -w.

    Although greatly a matter of style, the "safest" practice is probably to
    specifically list all constants in the "use Win32::TieRegistry"
    statement, specify "use strict" [or at least "use strict qw(subs)"], and
    use bare constant names when you want the numeric value. This will
    detect mispelled constant names at compile time.

        use strict;
        my $Registry;
        use Win32::TieRegistry 0.20 (
            TiedRef => \$Registry,  Delimiter => "/",  ArrayValues => 1,
            SplitMultis => 1,  AllowLoad => 1,
            qw( REG_SZ REG_EXPAND_SZ REG_DWORD REG_BINARY REG_MULTI_SZ
                KEY_READ KEY_WRITE KEY_ALL_ACCESS ),
        );
        $Registry->{"LMachine/Software/FooCorp/"}= {
            "FooWriter/" => {
                "/Fonts" => [ ["Times","Courier","Lucinda"], REG_MULTI_SZ ],
                "/WindowSize" => [ pack("LL",24,80), REG_BINARY ],
                "/TaskBarIcon" => [ "0x0001", REG_DWORD ],
            },
        }  or  die "Can't create Software/FooCorp/: $^E\n";

    If you don't want to "use strict qw(subs)", the second safest practice
    is similar to the above but use the "REG_SZ()" form for constants when
    possible and quoted constant names when required. Note that "qw()" is a
    form of quoting.

        use Win32::TieRegistry 0.20 qw(
            TiedRef $Registry
            Delimiter /  ArrayValues 1  SplitMultis 1  AllowLoad 1
            REG_SZ REG_EXPAND_SZ REG_DWORD REG_BINARY REG_MULTI_SZ
            KEY_READ KEY_WRITE KEY_ALL_ACCESS
        );
        $Registry->{"LMachine/Software/FooCorp/"}= {
            "FooWriter/" => {
                "/Fonts" => [ ["Times","Courier","Lucinda"], REG_MULTI_SZ() ],
                "/WindowSize" => [ pack("LL",24,80), REG_BINARY() ],
                "/TaskBarIcon" => [ "0x0001", REG_DWORD() ],
            },
        }  or  die "Can't create Software/FooCorp/: $^E\n";

    The examples in this document mostly use quoted constant names
    ("REG_SZ") since that works regardless of which constants you imported
    and whether or not you have "use strict" in your script. It is not the
    best choice for you to use for real scripts (vs. examples) because it is
    less efficient and is not supported by most other similar modules.

SUMMARY
    Most things can be done most easily via tied hashes. Skip down to the
    the "Tied Hashes Summary" to get started quickly.

  Objects Summary
    Here are quick examples that document the most common functionality of
    all of the method functions [except for a few almost useless ones].

        # Just another way of saying Open():
        $key= new Win32::TieRegistry "LMachine\\Software\\",
          { Access=>KEY_READ()|KEY_WRITE(), Delimiter=>"\\" };

        # Open a Registry key:
        $subKey= $key->Open( "SubKey/SubSubKey/",
          { Access=>KEY_ALL_ACCESS, Delimiter=>"/" } );

        # Connect to a remote Registry key:
        $remKey= $Registry->Connect( "MachineName", "LMachine/",
          { Access=>KEY_READ, Delimiter=>"/" } );

        # Get value data:
        $valueString= $key->GetValue("ValueName");
        ( $valueString, $valueType )= $key->GetValue("ValueName");

        # Get list of value names:
        @valueNames= $key->ValueNames;

        # Get list of subkey names:
        @subKeyNames= $key->SubKeyNames;

        # Get combined list of value names (with leading delimiters)
        # and subkey names (with trailing delimiters):
        @memberNames= $key->MemberNames;

        # Get all information about a key:
        %keyInfo= $key->Information;
        # keys(%keyInfo)= qw( Class LastWrite SecurityLen
        #   CntSubKeys MaxSubKeyLen MaxSubClassLen
        #   CntValues MaxValNameLen MaxValDataLen );

        # Get selected information about a key:
        ( $class, $cntSubKeys )= $key->Information( "Class", "CntSubKeys" );

        # Get and/or set delimiter:
        $delim= $key->Delimiter;
        $oldDelim= $key->Delimiter( $newDelim );

        # Get "path" for an open key:
        $path= $key->Path;
        # For example, "/CUser/Control Panel/Mouse/"
        # or "//HostName/LMachine/System/DISK/".

        # Get name of machine where key is from:
        $mach= $key->Machine;
        # Will usually be "" indicating key is on local machine.

        # Control different options (see main documentation for descriptions):
        $oldBool= $key->ArrayValues( $newBool );
        $oldBool= $key->FastDelete( $newBool );
        $oldBool= $key->FixSzNulls( $newBool );
        $oldBool= $key->SplitMultis( $newBool );
        $oldBool= $key->DWordsToHex( $newBool );
        $oldBool= $key->DualBinVals( $newBool );
        $oldBool= $key->DualTypes( $newBool );
        @oldBools= $key->SetOptions( ArrayValues=>1, FastDelete=>1, FixSzNulls=>0,
          Delimiter=>"/", AllowLoad=>1, AllowSave=>1 );
        @oldBools= $key->GetOptions( ArrayValues, FastDelete, FixSzNulls );

        # Add or set a value:
        $key->SetValue( "ValueName", $valueDataString );
        $key->SetValue( "ValueName", pack($format,$valueData), "REG_BINARY" );

        # Add or set a key:
        $key->CreateKey( "SubKeyName" );
        $key->CreateKey( "SubKeyName",
          { Access=>"KEY_ALL_ACCESS", Class=>"ClassName",
            Delimiter=>"/", Volatile=>1, Backup=>1 } );

        # Load an off-line Registry hive file into the on-line Registry:
        $newKey= $Registry->Load( "C:/Path/To/Hive/FileName" );
        $newKey= $key->Load( "C:/Path/To/Hive/FileName", "NewSubKeyName",
                         { Access=>"KEY_READ" } );
        # Unload a Registry hive file loaded via the Load() method:
        $newKey->UnLoad;

        # (Dis)Allow yourself to load Registry hive files:
        $success= $Registry->AllowLoad( $bool );

        # (Dis)Allow yourself to save a Registry key to a hive file:
        $success= $Registry->AllowSave( $bool );

        # Save a Registry key to a new hive file:
        $key->RegSaveKey( "C:/Path/To/Hive/FileName", [] );

   Other Useful Methods
    See *Win32API::Registry* for more information on these methods. These
    methods are provided for coding convenience and are identical to the
    *Win32API::Registry* functions except that these don't take a handle to
    a Registry key, instead getting the handle from the invoking object
    [$key].

        $key->RegGetKeySecurity( $iSecInfo, $sSecDesc, $lenSecDesc );
        $key->RegLoadKey( $sSubKeyName, $sPathToFile );
        $key->RegNotifyChangeKeyValue(
          $bWatchSubtree, $iNotifyFilter, $hEvent, $bAsync );
        $key->RegQueryMultipleValues(
          $structValueEnts, $cntValueEnts, $Buffer, $lenBuffer );
        $key->RegReplaceKey( $sSubKeyName, $sPathToNewFile, $sPathToBackupFile );
        $key->RegRestoreKey( $sPathToFile, $iFlags );
        $key->RegSetKeySecurity( $iSecInfo, $sSecDesc );
        $key->RegUnLoadKey( $sSubKeyName );

  Tied Hashes Summary
    For fast learners, this may be the only section you need to read. Always
    append one delimiter to the end of each Registry key name and prepend
    one delimiter to the front of each Registry value name.

   Opening keys
        use Win32::TieRegistry ( Delimiter=>"/", ArrayValues=>1 );
        $Registry->Delimiter("/");                  # Set delimiter to "/".
        $swKey= $Registry->{"LMachine/Software/"};
        $winKey= $swKey->{"Microsoft/Windows/CurrentVersion/"};
        $userKey= $Registry->
          {"CUser/Software/Microsoft/Windows/CurrentVersion/"};
        $remoteKey= $Registry->{"//HostName/LMachine/"};

   Reading values
        $progDir= $winKey->{"/ProgramFilesDir"};    # "C:\\Program Files"
        $tip21= $winKey->{"Explorer/Tips//21"};     # Text of tip #21.

        $winKey->ArrayValues(1);
        ( $devPath, $type )= $winKey->{"/DevicePath"};
        # $devPath eq "%SystemRoot%\\inf"
        # $type eq "REG_EXPAND_SZ"  [if you have SetDualVar.pm installed]
        # $type == REG_EXPAND_SZ()  [if did C<use Win32::TieRegistry qw(:REG_)>]

   Setting values
        $winKey->{"Setup//SourcePath"}= "\\\\SwServer\\SwShare\\Windows";
        # Simple.  Assumes data type of REG_SZ.

        $winKey->{"Setup//Installation Sources"}=
          [ "D:\x00\\\\SwServer\\SwShare\\Windows\0\0", "REG_MULTI_SZ" ];
        # "\x00" and "\0" used to mark ends of each string and end of list.

        $winKey->{"Setup//Installation Sources"}=
          [ ["D:","\\\\SwServer\\SwShare\\Windows"], "REG_MULTI_SZ" ];
        # Alternate method that is easier to read.

        $userKey->{"Explorer/Tips//DisplayInitialTipWindow"}=
          [ pack("L",0), "REG_DWORD" ];
        $userKey->{"Explorer/Tips//Next"}= [ pack("S",3), "REG_BINARY" ];
        $userKey->{"Explorer/Tips//Show"}= [ pack("L",0), "REG_BINARY" ];

   Adding keys
        $swKey->{"FooCorp/"}= {
            "FooWriter/" => {
                "/Version" => "4.032",
                "Startup/" => {
                    "/Title" => "Foo Writer Deluxe ][",
                    "/WindowSize" => [ pack("LL",$wid,$ht), "REG_BINARY" ],
                    "/TaskBarIcon" => [ "0x0001", "REG_DWORD" ],
                },
                "Compatibility/" => {
                    "/AutoConvert" => "Always",
                    "/Default Palette" => "Windows Colors",
                },
            },
            "/License", => "0123-9C8EF1-09-FC",
        };

   Listing all subkeys and values
        @members= keys( %{$swKey} );
        @subKeys= grep(  m#^/#,  keys( %{$swKey->{"Classes/batfile/"}} )  );
        # @subKeys= ( "/", "/EditFlags" );
        @valueNames= grep(  ! m#^/#,  keys( %{$swKey->{"Classes/batfile/"}} )  );
        # @valueNames= ( "DefaultIcon/", "shell/", "shellex/" );

   Deleting values or keys with no subkeys
        $oldValue= delete $userKey->{"Explorer/Tips//Next"};

        $oldValues= delete $userKey->{"Explorer/Tips/"};
        # $oldValues will be reference to hash containing deleted keys values.

   Closing keys
        undef $swKey;               # Explicit way to close a key.
        $winKey= "Anything else";   # Implicitly closes a key.
        exit 0;                     # Implicitly closes all keys.

  Tie::Registry
    This module was originally called *Tie::Registry*. Changing code that
    used *Tie::Registry* over to *Win32::TieRegistry* is trivial as the
    module name should only be mentioned once, in the "use" line. However,
    finding all of the places that used *Tie::Registry* may not be
    completely trivial so we have included Tie/Registry.pm which you can
    install to provide backward compatibility.

AUTHOR
    Tye McQueen. See http://www.metronet.com/~tye/ or e-mail
    tye@metronet.com with bug reports.

SEE ALSO
    *Win32API::Registry* - Provides access to "Reg*()", "HKEY_*", "KEY_*",
    "REG_*" [required].

    *Win32::WinError* - Defines "ERROR_*" values [optional].

    SetDualVar - For returning "REG_*" values as combined string/integer
    values [optional].

BUGS
    Perl5.004_02 has bugs that make *Win32::TieRegistry* fail in strange and
    subtle ways.

    Using *Win32::TieRegistry* with versions of Perl prior to 5.005 can be
    tricky or impossible. Most notes about this have been removed from the
    documentation (they get rather complicated and confusing). This includes
    references to $^E perhaps not being meaningful.

    Because Perl hashes are case sensitive, certain lookups are also case
    sensistive. In particular, the root keys ("Classes", "CUser",
    "LMachine", "Users", "PerfData", "CConfig", "DynData", and HKEY_*) must
    always be entered without changing between upper and lower case letters.
    Also, the special rule for matching subkey names that contain the
    user-selected delimiter only works if case is matched. All other key
    name and value name lookups should be case insensitive because the
    underlying Reg*() calls ignore case.

    Information about each key is cached when using a tied hash. This cache
    is not flushed nor updated when changes are made, *even when the same
    tied hash is used* to make the changes.

    Current implementations of Perl's "global destruction" phase can cause
    objects returned by "Load()" to be destroyed while keys within the hive
    are still open, if the objects still exist when the script starts to
    exit. When this happens, the automatic "UnLoad()" will report a failure
    and the hive will remain loaded in the Registry.

    Trying to "Load()" a hive file that is located on a remote network share
    may silently delete all data from the hive. This is a bug in the Win32
    APIs, not any Perl code or modules. This module does not try to protect
    you from this bug.

    There is no test suite.

FUTURE DIRECTIONS
    The following items are desired by the author and may appear in a future
    release of this module.

    TieValues option
        Currently described in main documentation but no yet implemented.

    AutoRefresh option
        Trigger use of "RegNotifyChangeKeyValue()" to keep tied hash caches
        up-to-date even when other programs make changes.

    Error options
        Allow the user to have unchecked calls (calls in a "void context")
        to automatically report errors via "warn" or "die".

        For complex operations, such a copying an entire subtree, provide
        access to detailed information about errors (and perhaps some
        warnings) that were encountered. Let the user control whether the
        complex operation continues in spite of errors.

COPYRIGHT
    Copyright 1999 - 2006 Tye McQueen.

    Some parts copyright 2007 - 2009 Adam Kennedy.

    This program is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

