# RegRead

Reads a value from the registry.

RegRead, OutputVar, RootKey, SubKey [, ValueName]

#### Parameters

OutputVar | The name of the variable in which to store the retrieved value. If the value cannot be retrieved, the variable is made blank and ErrorLevel is set to 1.
RootKey | Must be either HKEY_LOCAL_MACHINE, HKEY_USERS, HKEY_CURRENT_USER, HKEY_CLASSES_ROOT, or HKEY_CURRENT_CONFIG (or the abbreviations for each of these, such as HKLM). To access a remote registry, prepend the computer name and a colon, as in this example: \\workstation01:HKEY_LOCAL_MACHINE
SubKey | The name of the subkey (e.g. Software\SomeApplication).
ValueName | The name of the value to retrieve. If omitted, Subkey's default value will be retrieved, which is the value displayed as "(Default)" by RegEdit. If there is no default value (that is, if RegEdit displays "value not set"), OutputVar is made blank and ErrorLevel is set to 1.

#### ErrorLevel

ErrorLevel is set to 1 if there was a problem (such as a nonexistent key or value) or 0 otherwise.

#### Remarks

Currently only the following value types are supported: REG_SZ, REG_EXPAND_SZ, REG_MULTI_SZ, REG_DWORD, and REG_BINARY.

REG_DWORD values are always expressed as positive decimal numbers.

Although no more than 64 KB of data can be read from REG_BINARY values, the other types are unlimited except under Windows 95/98/ME, which have a 64 KB limit for all types (the Win9x registry is not capable of storing larger values).

When reading a REG_BINARY key the result is a string of hex characters. For example, the REG_BINARY value of 01,a9,ff,77 will be read as the string 01A9FF77.

When reading a REG_MULTI_SZ key, each of the components ends in a linefeed character (`n). If there are no components, OutputVar will be made blank. See FileSelectFile for an example of how to extract the individual components from OutputVar. Note: Windows 95 does not support the REG_MULTI_SZ value type.

To retrieve and operate upon multiple registry keys or values, consider using a registry-loop.

For details about how to access the registry of a remote computer, see the remarks in registry-loop.

To read and write entries from the 64-bit sections of the registry, see www.autohotkey.com/forum/topic39560.html

#### Related

RegDelete, RegWrite, Registry-loop, IniRead

#### Example

    RegRead, OutputVar, HKEY_LOCAL_MACHINE, SOFTWARE\Microsoft\Windows\CurrentVersion, ProgramFilesDir
    MsgBox, Program files are in: %OutputVar%

    ; The following example retrieves  the TYPE of a registry value (e.g. REG_SZ or REG_DWORD).
    MsgBox % RegKeyType("HKCU", "Environment", "TEMP")
    return

    RegKeyType(RootKey, SubKey, ValueName)  ; This function returns the type of the specified value.
    {
        Loop, %RootKey%, %SubKey%
            if (A_LoopRegName = ValueName)
                return A_LoopRegType
        return "Error"
    }