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Linux 2.6 - man page for win32reg (linux section 3erl)

win32reg(3erl)			     Erlang Module Definition			   win32reg(3erl)

       win32reg - win32reg provides access to the registry on Windows

       win32reg  provides  read  and write access to the registry on Windows. It is essentially a
       port driver wrapped around the Win32 API calls for accessing the registry.

       The registry is a hierarchical database, used to store various system and software  infor-
       mation  in Windows. It is available in Windows 95 and Windows NT. It contains installation
       data, and is updated by installers and system programs. The Erlang installer  updates  the
       registry by adding data that Erlang needs.

       The  registry  contains	keys  and values. Keys are like the directories in a file system,
       they form a hierarchy. Values are like files, they have a name and a  value,  and  also	a

       Paths  to  keys	are left to right, with sub-keys to the right and backslash between keys.
       (Remember that backslashes must be doubled in Erlang strings.) Case is preserved  but  not
       significant.  Example:  "\\hkey_local_machine\\software\\Ericsson\\Erlang\\5.0" is the key
       for the installation data for the latest Erlang release.

       There are six entry points in the Windows registry, top level keys. They can  be  abbrevi-
       ated in the win32reg module as:

       Abbrev.		Registry key
       =======		============
       hkcr		HKEY_CLASSES_ROOT
       current_user	HKEY_CURRENT_USER
       hkcu		HKEY_CURRENT_USER
       local_machine	HKEY_LOCAL_MACHINE
       users		HKEY_USERS
       hku		HKEY_USERS
       current_config	HKEY_CURRENT_CONFIG
       dyn_data 	HKEY_DYN_DATA
       hkdd		HKEY_DYN_DATA

       The key above could be written as "\\hklm\\software\\ericsson\\erlang\\5.0" .

       The win32reg module uses a current key. It works much like the current directory. From the
       current key, values can be fetched, sub-keys can be listed, and so on.

       Under a key, any number of named values can be stored. They  have  name,  and  types,  and

       Currently, the win32reg module supports storing only the following types: REG_DWORD, which
       is an integer, REG_SZ which is a string and REG_BINARY which is a binary. Other types  can
       be read, and will be returned as binaries.

       There  is also a "default" value, which has the empty string as name. It is read and writ-
       ten with the atom default instead of the name.

       Some registry values are stored as strings with references to environment variables,  e.g.
       "%SystemRoot%Windows" . SystemRoot is an environment variable, and should be replaced with
       its value. A function expand/1 is provided, so that environment variables surrounded in	%
       can be expanded to their values.

       For  additional	information on the Windows registry consult the Win32 Programmer's Refer-

       change_key(RegHandle, Key) -> ReturnValue

	      Types  RegHandle = term()
		     Key = string()

	      Changes the current key to another key. Works like cd. The key can be specified  as
	      a relative path or as an absolute path, starting with \.

       change_key_create(RegHandle, Key) -> ReturnValue

	      Types  RegHandle = term()
		     Key = string()

	      Creates a key, or just changes to it, if it is already there. Works like a combina-
	      tion of mkdir and cd . Calls the Win32 API function RegCreateKeyEx() .

	      The registry must have been opened in write-mode.

       close(RegHandle)-> ReturnValue

	      Types  RegHandle = term()

	      Closes the registry. After that, the RegHandle cannot be used.

       current_key(RegHandle) -> ReturnValue

	      Types  RegHandle = term()
		     ReturnValue = {ok, string()}

	      Returns the path to the current key. This is the equivalent of pwd .

	      Note that the current key is stored in the driver, and might be  invalid	(e.g.  if
	      the key has been removed).

       delete_key(RegHandle) -> ReturnValue

	      Types  RegHandle = term()
		     ReturnValue = ok | {error, ErrorId}

	      Deletes	the   current  key,  if  it  is  valid.  Calls	the  Win32  API  function
	      RegDeleteKey() . Note that this call does  not  change  the  current  key,  (unlike
	      change_key_create/2 .) This means that after the call, the current key is invalid.

       delete_value(RegHandle, Name) -> ReturnValue

	      Types  RegHandle = term()
		     ReturnValue = ok | {error, ErrorId}

	      Deletes  a  named  value	on  the current key. The atom default is used for the the
	      default value.

	      The registry must have been opened in write-mode.

       expand(String) -> ExpandedString

	      Types  String = string()
		     ExpandedString = string()

	      Expands a string containing environment variables between percent characters.  Any-
	      thing  between  two  %  is taken for a environment variable, and is replaced by the
	      value. Two consecutive % is replaced by one %.

	      A variable name that is not in the environment, will result in an error.

       format_error(ErrorId) -> ErrorString

	      Types  ErrorId = atom()
		     ErrorString = string()

	      Convert an POSIX errorcode to a string (by calling erl_posix_msg:message ).

       open(OpenModeList)-> ReturnValue

	      Types  OpenModeList = [OpenMode]
		     OpenMode = read | write

	      Opens the registry for reading or writing. The current  key  will  be  the  root	(
	      HKEY_CLASSES_ROOT ). The read flag in the mode list can be omitted.

	      Use change_key/2 with an absolute path after open .

       set_value(RegHandle, Name, Value) -> ReturnValue

	      Types  Name = string() | default
		     Value = string() | integer() | binary()

	      Sets the named (or default) value to value. Calls the Win32 API function RegSetVal-
	      ueEx() . The value can be of three types, and the corresponding registry type  will
	      be  used.  Currently  the  types	supported are: REG_DWORD for integers, REG_SZ for
	      strings and REG_BINARY for binaries. Other  types  cannot  currently  be	added  or

	      The registry must have been opened in write-mode.

       sub_keys(RegHandle) -> ReturnValue

	      Types  ReturnValue = {ok, SubKeys} | {error, ErrorId}
		     SubKeys = [SubKey]
		     SubKey = string()

	      Returns  a  list	of subkeys to the current key. Calls the Win32 API function Enum-
	      RegKeysEx() .

	      Avoid calling this on the root keys, it can be slow.

       value(RegHandle, Name) -> ReturnValue

	      Types  Name = string() | default
		     ReturnValue = {ok, Value}
		     Value = string() | integer() | binary()

	      Retrieves the named value (or default) on the current key. Registry values of  type
	      REG_SZ  ,  are returned as strings. Type REG_DWORD values are returned as integers.
	      All other types are returned as binaries.

       values(RegHandle) -> ReturnValue

	      Types  ReturnValue = {ok, ValuePairs} | {ok, ErrorId}
		     ValuePairs = [ValuePair]
		     ValuePair = {Name, Value}
		     Name = string | default
		     Value = string() | integer() | binary()

	      Retrieves a list of all values on the current key. The  values  have  types  corre-
	      sponding	to  the registry types, see value . Calls the Win32 API function EnumReg-
	      ValuesEx() .

       Win32 Programmer's Reference (from Microsoft)


       The Windows 95 Registry (book from O'Reilly)

Ericsson AB				  stdlib 1.17.3 			   win32reg(3erl)

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