Provided by: libhivex-dev_1.3.13-1build3_amd64 bug

NAME

       hivex - Windows Registry "hive" extraction library

SYNOPSIS

        #include <hivex.h>

        hive_h *hivex_open (const char *filename, int flags);
        int hivex_close (hive_h *h);
        hive_node_h hivex_root (hive_h *h);
        int64_t hivex_last_modified (hive_h *h);
        char *hivex_node_name (hive_h *h, hive_node_h node);
        size_t hivex_node_name_len (hive_h *h, hive_node_h node);
        int64_t hivex_node_timestamp (hive_h *h, hive_node_h node);
        hive_node_h *hivex_node_children (hive_h *h, hive_node_h node);
        hive_node_h hivex_node_get_child (hive_h *h, hive_node_h node, const char *name);
        hive_node_h hivex_node_parent (hive_h *h, hive_node_h node);
        hive_value_h *hivex_node_values (hive_h *h, hive_node_h node);
        hive_value_h hivex_node_get_value (hive_h *h, hive_node_h node, const char *key);
        size_t hivex_value_key_len (hive_h *h, hive_value_h val);
        char *hivex_value_key (hive_h *h, hive_value_h val);
        int hivex_value_type (hive_h *h, hive_value_h val, hive_type *t, size_t *len);
        size_t hivex_node_struct_length (hive_h *h, hive_node_h node);
        size_t hivex_value_struct_length (hive_h *h, hive_value_h val);
        hive_value_h hivex_value_data_cell_offset (hive_h *h, hive_value_h val, size_t *len);
        char *hivex_value_value (hive_h *h, hive_value_h val, hive_type *t, size_t *len);
        char *hivex_value_string (hive_h *h, hive_value_h val);
        char **hivex_value_multiple_strings (hive_h *h, hive_value_h val);
        int32_t hivex_value_dword (hive_h *h, hive_value_h val);
        int64_t hivex_value_qword (hive_h *h, hive_value_h val);
        int hivex_commit (hive_h *h, const char *filename, int flags);
        hive_node_h hivex_node_add_child (hive_h *h, hive_node_h parent, const char *name);
        int hivex_node_delete_child (hive_h *h, hive_node_h node);
        int hivex_node_set_values (hive_h *h, hive_node_h node, size_t nr_values, const hive_set_value *values, int flags);
        int hivex_node_set_value (hive_h *h, hive_node_h node, const hive_set_value *val, int flags);

       Link with -lhivex.

DESCRIPTION

       Hivex is a library for extracting the contents of Windows Registry "hive" files.  It is
       designed to be secure against buggy or malicious registry files.

       Unlike other tools in this area, it doesn't use the textual .REG format, because parsing
       that is as much trouble as parsing the original binary format.  Instead it makes the file
       available through a C API, and then wraps this API in higher level scripting and GUI
       tools.

       There is a separate program to export the hive as XML (see hivexml(1)), or to navigate the
       file (see hivexsh(1)).  There is also a Perl script to export and merge the file as a
       textual .REG (regedit) file, see hivexregedit(1).

       If you just want to export or modify the Registry of a Windows virtual machine, you should
       look at virt-win-reg(1).

       Hivex is also comes with language bindings for OCaml, Perl, Python and Ruby.

TYPES

   "hive_h *"
       This handle describes an open hive file.

   "hive_node_h"
       This is a node handle, an integer but opaque outside the library.  Valid node handles
       cannot be 0.  The library returns 0 in some situations to indicate an error.

   "hive_type"
       The enum below describes the possible types for the value(s) stored at each node.  Note
       that you should not trust the type field in a Windows Registry, as it very often has no
       relationship to reality.  Some applications use their own types.  The encoding of strings
       is not specified.  Some programs store everything (including strings) in binary blobs.

        enum hive_type {
          /* Just a key without a value */
          hive_t_REG_NONE = 0,
          /* A Windows string (encoding is unknown, but often UTF16-LE) */
          hive_t_REG_SZ = 1,
          /* A Windows string that contains %env% (environment variable expansion) */
          hive_t_REG_EXPAND_SZ = 2,
          /* A blob of binary */
          hive_t_REG_BINARY = 3,
          /* DWORD (32 bit integer), little endian */
          hive_t_REG_DWORD = 4,
          /* DWORD (32 bit integer), big endian */
          hive_t_REG_DWORD_BIG_ENDIAN = 5,
          /* Symbolic link to another part of the registry tree */
          hive_t_REG_LINK = 6,
          /* Multiple Windows strings.  See http://blogs.msdn.com/oldnewthing/archive/2009/10/08/9904646.aspx */
          hive_t_REG_MULTI_SZ = 7,
          /* Resource list */
          hive_t_REG_RESOURCE_LIST = 8,
          /* Resource descriptor */
          hive_t_REG_FULL_RESOURCE_DESCRIPTOR = 9,
          /* Resouce requirements list */
          hive_t_REG_RESOURCE_REQUIREMENTS_LIST = 10,
          /* QWORD (64 bit integer), unspecified endianness but usually little endian */
          hive_t_REG_QWORD = 11,
       };

   "hive_value_h"
       This is a value handle, an integer but opaque outside the library.  Valid value handles
       cannot be 0.  The library returns 0 in some situations to indicate an error.

   "hive_set_value"
       The typedef "hive_set_value" is used in conjunction with the "hivex_node_set_values" call
       described below.

        struct hive_set_value {
          char *key;     /* key - a UTF-8 encoded ASCIIZ string */
          hive_type t;   /* type of value field */
          size_t len;    /* length of value field in bytes */
          char *value;   /* value field */
        };
        typedef struct hive_set_value hive_set_value;

       To set the default value for a node, you have to pass "key = """.

       Note that the "value" field is just treated as a list of bytes, and is stored directly in
       the hive.  The caller has to ensure correct encoding and endianness, for example
       converting dwords to little endian.

       The correct type and encoding for values depends on the node and key in the registry, the
       version of Windows, and sometimes even changes between versions of Windows for the same
       key.  We don't document it here.  Often it's not documented at all.

FUNCTIONS

   hivex_open
        hive_h *hivex_open (const char *filename, int flags);

       Opens the hive named "filename" for reading.

       Flags is an ORed list of the open flags (or 0 if you don't want to pass any flags).  These
       flags are defined:

       HIVEX_OPEN_VERBOSE
           Verbose messages.

       HIVEX_OPEN_DEBUG
           Very verbose messages, suitable for debugging problems in the library itself.

           This is also selected if the "HIVEX_DEBUG" environment variable is set to 1.

       HIVEX_OPEN_WRITE
           Open the hive for writing.  If omitted, the hive is read-only.

           See "WRITING TO HIVE FILES" in hivex(3).

       Returns a new hive handle.  On error this returns NULL and sets errno.

   hivex_close
        int hivex_close (hive_h *h);

       Close a hive handle and free all associated resources.

       Note that any uncommitted writes are not committed by this call, but instead are lost.
       See "WRITING TO HIVE FILES" in hivex(3).

       Returns 0 on success.  On error this returns -1 and sets errno.

       This function frees the hive handle (even if it returns an error).  The hive handle must
       not be used again after calling this function.

   hivex_root
        hive_node_h hivex_root (hive_h *h);

       Return root node of the hive.  All valid hives must contain a root node.

       Returns a node handle.  On error this returns 0 and sets errno.

   hivex_last_modified
        int64_t hivex_last_modified (hive_h *h);

       Return the modification time from the header of the hive.

       The returned value is a Windows filetime.  To convert this to a Unix "time_t" see:
       <http://stackoverflow.com/questions/6161776/convert-windows-filetime-to-second-in-unix-linux/6161842#6161842>

   hivex_node_name
        char *hivex_node_name (hive_h *h, hive_node_h node);

       Return the name of the node.

       Note that the name of the root node is a dummy, such as "$$$PROTO.HIV" (other names are
       possible: it seems to depend on the tool or program that created the hive in the first
       place).  You can only know the "real" name of the root node by knowing which registry file
       this hive originally comes from, which is knowledge that is outside the scope of this
       library.

       The name is recoded to UTF-8 and may contain embedded NUL characters.

       Returns a string.  The string must be freed by the caller when it is no longer needed.  On
       error this returns NULL and sets errno.

   hivex_node_name_len
        size_t hivex_node_name_len (hive_h *h, hive_node_h node);

       Return the length of the node name as produced by "hivex_node_name".

       Returns a size.  On error this returns 0 and sets errno.

   hivex_node_timestamp
        int64_t hivex_node_timestamp (hive_h *h, hive_node_h node);

       Return the modification time of the node.

       The returned value is a Windows filetime.  To convert this to a Unix "time_t" see:
       <http://stackoverflow.com/questions/6161776/convert-windows-filetime-to-second-in-unix-linux/6161842#6161842>

   hivex_node_children
        hive_node_h *hivex_node_children (hive_h *h, hive_node_h node);

       Return an array of nodes which are the subkeys (children) of "node".

       Returns a 0-terminated array of nodes.  The array must be freed by the caller when it is
       no longer needed.  On error this returns NULL and sets errno.

   hivex_node_get_child
        hive_node_h hivex_node_get_child (hive_h *h, hive_node_h node, const char *name);

       Return the child of node with the name "name", if it exists.

       The name is matched case insensitively.

       Returns a node handle.  If the node was not found, this returns 0 without setting errno.
       On error this returns 0 and sets errno.

   hivex_node_parent
        hive_node_h hivex_node_parent (hive_h *h, hive_node_h node);

       Return the parent of "node".

       The parent pointer of the root node in registry files that we have examined seems to be
       invalid, and so this function will return an error if called on the root node.

       Returns a node handle.  On error this returns 0 and sets errno.

   hivex_node_values
        hive_value_h *hivex_node_values (hive_h *h, hive_node_h node);

       Return the array of (key, value) pairs attached to this node.

       Returns a 0-terminated array of values.  The array must be freed by the caller when it is
       no longer needed.  On error this returns NULL and sets errno.

   hivex_node_get_value
        hive_value_h hivex_node_get_value (hive_h *h, hive_node_h node, const char *key);

       Return the value attached to this node which has the name "key", if it exists.

       The key name is matched case insensitively.

       Note that to get the default key, you should pass the empty string "" here.  The default
       key is often written "@", but inside hives that has no meaning and won't give you the
       default key.

       Returns a value handle.  On error this returns 0 and sets errno.

   hivex_value_key_len
        size_t hivex_value_key_len (hive_h *h, hive_value_h val);

       Return the length of the key (name) of a (key, value) pair as produced by
       "hivex_value_key". The length can legitimately be 0, so errno is the necessary mechanism
       to check for errors.

       In the context of Windows Registries, a zero-length name means that this value is the
       default key for this node in the tree.  This is usually written as "@".

       The key is recoded to UTF-8 and may contain embedded NUL characters.

       Returns a size.  On error this returns 0 and sets errno.

   hivex_value_key
        char *hivex_value_key (hive_h *h, hive_value_h val);

       Return the key (name) of a (key, value) pair.  The name is reencoded as UTF-8 and returned
       as a string.

       The string should be freed by the caller when it is no longer needed.

       Note that this function can return a zero-length string.  In the context of Windows
       Registries, this means that this value is the default key for this node in the tree.  This
       is usually written as "@".

       Returns a string.  The string must be freed by the caller when it is no longer needed.  On
       error this returns NULL and sets errno.

   hivex_value_type
        int hivex_value_type (hive_h *h, hive_value_h val, hive_type *t, size_t *len);

       Return the data length and data type of the value in this (key, value) pair.  See also
       "hivex_value_value" which returns all this information, and the value itself.  Also,
       "hivex_value_*" functions below which can be used to return the value in a more useful
       form when you know the type in advance.

       Returns 0 on success.  On error this returns -1 and sets errno.

   hivex_node_struct_length
        size_t hivex_node_struct_length (hive_h *h, hive_node_h node);

       Return the length of the node data structure.

       Returns a size.  On error this returns 0 and sets errno.

   hivex_value_struct_length
        size_t hivex_value_struct_length (hive_h *h, hive_value_h val);

       Return the length of the value data structure.

       Returns a size.  On error this returns 0 and sets errno.

   hivex_value_data_cell_offset
        hive_value_h hivex_value_data_cell_offset (hive_h *h, hive_value_h val, size_t *len);

       Return the offset and length of the value's data cell.

       The data cell is a registry structure that contains the length (a 4 byte, little endian
       integer) followed by the data.

       If the length of the value is less than or equal to 4 bytes then the offset and length
       returned by this function is zero as the data is inlined in the value.

       Returns 0 and sets errno on error.

       Returns a value handle.  On error this returns 0 and sets errno.

   hivex_value_value
        char *hivex_value_value (hive_h *h, hive_value_h val, hive_type *t, size_t *len);

       Return the value of this (key, value) pair.  The value should be interpreted according to
       its type (see "hive_type").

       The value is returned as an array of bytes (of length "len").  The value must be freed by
       the caller when it is no longer needed.  On error this returns NULL and sets errno.

   hivex_value_string
        char *hivex_value_string (hive_h *h, hive_value_h val);

       If this value is a string, return the string reencoded as UTF-8 (as a C string).  This
       only works for values which have type "hive_t_string", "hive_t_expand_string" or
       "hive_t_link".

       Returns a string.  The string must be freed by the caller when it is no longer needed.  On
       error this returns NULL and sets errno.

   hivex_value_multiple_strings
        char **hivex_value_multiple_strings (hive_h *h, hive_value_h val);

       If this value is a multiple-string, return the strings reencoded as UTF-8 (in C, as a
       NULL-terminated array of C strings, in other language bindings, as a list of strings).
       This only works for values which have type "hive_t_multiple_strings".

       Returns a NULL-terminated array of C strings.  The strings and the array must all be freed
       by the caller when they are no longer needed.  On error this returns NULL and sets errno.

   hivex_value_dword
        int32_t hivex_value_dword (hive_h *h, hive_value_h val);

       If this value is a DWORD (Windows int32), return it.  This only works for values which
       have type "hive_t_dword" or "hive_t_dword_be".

   hivex_value_qword
        int64_t hivex_value_qword (hive_h *h, hive_value_h val);

       If this value is a QWORD (Windows int64), return it.  This only works for values which
       have type "hive_t_qword".

   hivex_commit
        int hivex_commit (hive_h *h, const char *filename, int flags);

       Commit (write) any changes which have been made.

       "filename" is the new file to write.  If "filename" is null/undefined then we overwrite
       the original file (ie. the file name that was passed to "hivex_open").

       Note this does not close the hive handle.  You can perform further operations on the hive
       after committing, including making more modifications.  If you no longer wish to use the
       hive, then you should close the handle after committing.

       The flags parameter is unused.  Always pass 0.

       Returns 0 on success.  On error this returns -1 and sets errno.

   hivex_node_add_child
        hive_node_h hivex_node_add_child (hive_h *h, hive_node_h parent, const char *name);

       Add a new child node named "name" to the existing node "parent".  The new child initially
       has no subnodes and contains no keys or values.  The sk-record (security descriptor) is
       inherited from the parent.

       The parent must not have an existing child called "name", so if you want to overwrite an
       existing child, call "hivex_node_delete_child" first.

       Returns a node handle.  On error this returns 0 and sets errno.

   hivex_node_delete_child
        int hivex_node_delete_child (hive_h *h, hive_node_h node);

       Delete the node "node".  All values at the node and all subnodes are deleted
       (recursively).  The "node" handle and the handles of all subnodes become invalid.  You
       cannot delete the root node.

       Returns 0 on success.  On error this returns -1 and sets errno.

   hivex_node_set_values
        int hivex_node_set_values (hive_h *h, hive_node_h node, size_t nr_values, const hive_set_value *values, int flags);

       This call can be used to set all the (key, value) pairs stored in "node".

       "node" is the node to modify.

       The flags parameter is unused.  Always pass 0.

       "values" is an array of (key, value) pairs.  There should be "nr_values" elements in this
       array.

       Any existing values stored at the node are discarded, and their "hive_value_h" handles
       become invalid.  Thus you can remove all values stored at "node" by passing "nr_values =
       0".

       Returns 0 on success.  On error this returns -1 and sets errno.

   hivex_node_set_value
        int hivex_node_set_value (hive_h *h, hive_node_h node, const hive_set_value *val, int flags);

       This call can be used to replace a single "(key, value)" pair stored in "node".  If the
       key does not already exist, then a new key is added.  Key matching is case insensitive.

       "node" is the node to modify.

       The flags parameter is unused.  Always pass 0.

       "value" is a single (key, value) pair.

       Existing "hive_value_h" handles become invalid.

       Returns 0 on success.  On error this returns -1 and sets errno.

WRITING TO HIVE FILES

       The hivex library supports making limited modifications to hive files.  We have tried to
       implement this very conservatively in order to reduce the chance of corrupting your
       registry.  However you should be careful and take back-ups, since Microsoft has never
       documented the hive format, and so it is possible there are nuances in the reverse-
       engineered format that we do not understand.

       To be able to modify a hive, you must pass the "HIVEX_OPEN_WRITE" flag to "hivex_open",
       otherwise any write operation will return with errno "EROFS".

       The write operations shown below do not modify the on-disk file immediately.  You must
       call "hivex_commit" in order to write the changes to disk.  If you call "hivex_close"
       without committing then any writes are discarded.

       Hive files internally consist of a "memory dump" of binary blocks (like the C heap), and
       some of these blocks can be unused.  The hivex library never reuses these unused blocks.
       Instead, to ensure robustness in the face of the partially understood on-disk format,
       hivex only allocates new blocks after the end of the file, and makes minimal modifications
       to existing structures in the file to point to these new blocks.  This makes hivex
       slightly less disk-efficient than it could be, but disk is cheap, and registry
       modifications tend to be very small.

       When deleting nodes, it is possible that this library may leave unreachable live blocks in
       the hive.  This is because certain parts of the hive disk format such as security (sk)
       records and big data (db) records and classname fields are not well understood (and not
       documented at all) and we play it safe by not attempting to modify them.  Apart from
       wasting a little bit of disk space, it is not thought that unreachable blocks are a
       problem.

   WRITE OPERATIONS WHICH ARE NOT SUPPORTED
       •   Changing the root node.

       •   Creating a new hive file from scratch.  This is impossible at present because not all
           fields in the header are understood.  In the hivex source tree is a file called
           "images/minimal" which could be used as the basis for a new hive (but caveat emptor).

       •   Modifying or deleting single values at a node.

       •   Modifying security key (sk) records or classnames.  Previously we did not understand
           these records.  However now they are well-understood and we could add support if it
           was required (but nothing much really uses them).

VISITING ALL NODES

       The visitor pattern is useful if you want to visit all nodes in the tree or all nodes
       below a certain point in the tree.

       First you set up your own "struct hivex_visitor" with your callback functions.

       Each of these callback functions should return 0 on success or -1 on error.  If any
       callback returns -1, then the entire visit terminates immediately.  If you don't need a
       callback function at all, set the function pointer to NULL.

        struct hivex_visitor {
          int (*node_start) (hive_h *, void *opaque, hive_node_h, const char *name);
          int (*node_end) (hive_h *, void *opaque, hive_node_h, const char *name);
          int (*value_string) (hive_h *, void *opaque, hive_node_h, hive_value_h,
                hive_type t, size_t len, const char *key, const char *str);
          int (*value_multiple_strings) (hive_h *, void *opaque, hive_node_h,
                hive_value_h, hive_type t, size_t len, const char *key, char **argv);
          int (*value_string_invalid_utf16) (hive_h *, void *opaque, hive_node_h,
                hive_value_h, hive_type t, size_t len, const char *key,
                const char *str);
          int (*value_dword) (hive_h *, void *opaque, hive_node_h, hive_value_h,
                hive_type t, size_t len, const char *key, int32_t);
          int (*value_qword) (hive_h *, void *opaque, hive_node_h, hive_value_h,
                hive_type t, size_t len, const char *key, int64_t);
          int (*value_binary) (hive_h *, void *opaque, hive_node_h, hive_value_h,
                hive_type t, size_t len, const char *key, const char *value);
          int (*value_none) (hive_h *, void *opaque, hive_node_h, hive_value_h,
                hive_type t, size_t len, const char *key, const char *value);
          int (*value_other) (hive_h *, void *opaque, hive_node_h, hive_value_h,
                hive_type t, size_t len, const char *key, const char *value);
          /* If value_any callback is not NULL, then the other value_*
           * callbacks are not used, and value_any is called on all values.
           */
          int (*value_any) (hive_h *, void *opaque, hive_node_h, hive_value_h,
                hive_type t, size_t len, const char *key, const char *value);
        };

       hivex_visit
            int hivex_visit (hive_h *h, const struct hivex_visitor *visitor, size_t len, void *opaque, int flags);

           Visit all the nodes recursively in the hive "h".

           "visitor" should be a "hivex_visitor" structure with callback fields filled in as
           required (unwanted callbacks can be set to NULL).  "len" must be the length of the
           'visitor' struct (you should pass "sizeof (struct hivex_visitor)" for this).

           This returns 0 if the whole recursive visit was completed successfully.  On error this
           returns -1.  If one of the callback functions returned an error than we don't touch
           errno.  If the error was generated internally then we set errno.

           You can skip bad registry entries by setting "flag" to "HIVEX_VISIT_SKIP_BAD".  If
           this flag is not set, then a bad registry causes the function to return an error
           immediately.

           This function is robust if the registry contains cycles or pointers which are invalid
           or outside the registry.  It detects these cases and returns an error.

       hivex_visit_node
            int hivex_visit_node (hive_h *h, hive_node_h node, const struct hivex_visitor *visitor, size_t len, void *opaque);

           Same as "hivex_visit" but instead of starting out at the root, this starts at "node".

THE STRUCTURE OF THE WINDOWS REGISTRY

       Note: To understand the relationship between hives and the common Windows Registry keys
       (like "HKEY_LOCAL_MACHINE") please see the Wikipedia page on the Windows Registry.

       The Windows Registry is split across various binary files, each file being known as a
       "hive".  This library only handles a single hive file at a time.

       Hives are n-ary trees with a single root.  Each node in the tree has a name.

       Each node in the tree (including non-leaf nodes) may have an arbitrary list of (key,
       value) pairs attached to it.  It may be the case that one of these pairs has an empty key.
       This is referred to as the default key for the node.

       The (key, value) pairs are the place where the useful data is stored in the registry.  The
       key is always a string (possibly the empty string for the default key).  The value is a
       typed object (eg. string, int32, binary, etc.).

   RELATIONSHIP TO .REG FILES
       The hivex C library does not care about or deal with Windows .REG files.  Instead we push
       this complexity up to the Perl Win::Hivex(3) library and the Perl programs hivexregedit(1)
       and virt-win-reg(1).  Nevertheless it is useful to look at the relationship between the
       Registry and .REG files because they are so common.

       A .REG file is a textual representation of the registry, or part of the registry.  The
       actual registry hives that Windows uses are binary files.  There are a number of Windows
       and Linux tools that let you generate .REG files, or merge .REG files back into the
       registry hives.  Notable amongst them is Microsoft's REGEDIT program (formerly known as
       REGEDT32).

       A typical .REG file will contain many sections looking like this:

        [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Stack]
        "@"="Generic Stack"
        "TileInfo"="prop:System.FileCount"
        "TilePath"=str(2):"%systemroot%\\system32"
        "ThumbnailCutoff"=dword:00000000
        "FriendlyTypeName"=hex(2):40,00,25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,\
         6f,00,74,00,25,00,5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,\
         33,00,32,00,5c,00,73,00,65,00,61,00,72,00,63,00,68,00,66,00,\
         6f,00,6c,00,64,00,65,00,72,00,2e,00,64,00,6c,00,6c,00,2c,00,\
         2d,00,39,00,30,00,32,00,38,00,00,00,d8

       Taking this one piece at a time:

        [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Stack]

       This is the path to this node in the registry tree.  The first part,
       "HKEY_LOCAL_MACHINE\SOFTWARE" means that this comes from a hive file called
       "C:\WINDOWS\SYSTEM32\CONFIG\SOFTWARE".  "\Classes\Stack" is the real path part, starting
       at the root node of the "SOFTWARE" hive.

       Below the node name is a list of zero or more key-value pairs.  Any interior or leaf node
       in the registry may have key-value pairs attached.

        "@"="Generic Stack"

       This is the "default key".  In reality (ie. inside the binary hive) the key string is the
       empty string.  In .REG files this is written as "@" but this has no meaning either in the
       hives themselves or in this library.  The value is a string (type 1 - see "enum hive_type"
       above).

        "TileInfo"="prop:System.FileCount"

       This is a regular (key, value) pair, with the value being a type 1 string.  Note that
       inside the binary file the string is likely to be UTF-16LE encoded.  This library converts
       to and from UTF-8 strings transparently in some cases.

        "TilePath"=str(2):"%systemroot%\\system32"

       The value in this case has type 2 (expanded string) meaning that some %...% variables get
       expanded by Windows.  (This library doesn't know or care about variable expansion).

        "ThumbnailCutoff"=dword:00000000

       The value in this case is a dword (type 4).

        "FriendlyTypeName"=hex(2):40,00,....

       This value is an expanded string (type 2) represented in the .REG file as a series of hex
       bytes.  In this case the string appears to be a UTF-16LE string.

NOTE ON THE USE OF ERRNO

       Many functions in this library set errno to indicate errors.  These are the values of
       errno you may encounter (this list is not exhaustive):

       ENOTSUP
           Corrupt or unsupported Registry file format.

       HIVEX_NO_KEY
           Missing root key.

       EINVAL
           Passed an invalid argument to the function.

       EFAULT
           Followed a Registry pointer which goes outside the registry or outside a registry
           block.

       ELOOP
           Registry contains cycles.

       ERANGE
           Field in the registry out of range.

       EEXIST
           Registry key already exists.

       EROFS
           Tried to write to a registry which is not opened for writing.

ENVIRONMENT VARIABLES

       HIVEX_DEBUG
           Setting HIVEX_DEBUG=1 will enable very verbose messages.  This is useful for debugging
           problems with the library itself.

SEE ALSO

       hivexget(1), hivexml(1), hivexsh(1), hivexregedit(1), virt-win-reg(1), Win::Hivex(3),
       guestfs(3), <http://libguestfs.org/>, virt-cat(1), virt-edit(1),
       <http://en.wikipedia.org/wiki/Windows_Registry>.

AUTHORS

       Richard W.M. Jones ("rjones at redhat dot com")

COPYRIGHT

       Copyright (C) 2009-2010 Red Hat Inc.

       Derived from code by Petter Nordahl-Hagen under a compatible license: Copyright (C)
       1997-2007 Petter Nordahl-Hagen.

       Derived from code by Markus Stephany under a compatible license: Copyright (C) 2000-2004
       Markus Stephany.

       This library is free software; you can redistribute it and/or modify it under the terms of
       the GNU Lesser General Public License as published by the Free Software Foundation;
       version 2.1 of the License only.

       This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       See the GNU Lesser General Public License for more details.