Can't write "null" binary data to registry

[Alan Clarke]

I want to write the following binary data to a key in my registry: [40 18 00 00 00 c0 46 c4] The first two bytes write, but when I reach the first "00", everything after that fails to write.

Here is my code:
'===========================
'Write binary data: [40 18 00 00 00 c0 46 c4] to registry @ HKLM\SYSTEM\Setup\test
#COMPILE EXE
$INCLUDE "WIN32API.INC"

FUNCTION SetReg(BYVAL hLocation AS DWORD, BYVAL sSubKeys AS STRING, BYVAL sValueName AS STRING, BYVAL sData AS STRING) AS LONG
LOCAL hKey AS DWORD, zRegName AS ASCIIZ * 20, zRegVal AS ASCIIZ * 20, dwType AS DWORD, dwSize AS DWORD
zRegVal = sData
zRegName = sValueName
IF RegCreateKeyEx(hLocation, TRIM$(sSubKeys, "\"), 0, "", 0, %KEY_WRITE, BYVAL %Null, hKey, BYVAL %Null) = %ERROR_SUCCESS THEN
' Set length of data...
dwSize = LEN(zRegVal)
'dwType = %REG_SZ
dwType = %REG_BINARY
IF RegSetValueEx(hKey, zRegName, 0, dwType, zRegVal, dwSize) = %ERROR_SUCCESS THEN FUNCTION = %True
RegCloseKey hKey
END IF
END FUNCTION

FUNCTION PBMAIN () AS LONG

hData$=CHR$(&H40)& CHR$(&H18)& CHR$(0)& CHR$(0)& CHR$(0)& CHR$(&H46)& CHR$(&HC4)

IF SetReg(%HKEY_LOCAL_MACHINE, "SYSTEM\Setup", "test", hData$) THEN
STDOUT "Success"
ELSE
STDOUT "Error"
END IF

END FUNCTION

[David Roberts]

Try this

#Compile Exe
$Include "WIN32API.INC"

Function SetReg(ByVal hLocation As Dword, ByVal sSubKeys As String, ByVal sValueName As String, sData As String) As Long
Local hKey As Dword, zRegName As Asciiz * 20, zRegVal As Asciiz * 20, dwType As Dword, dwSize As Dword
zRegVal = sData
zRegName = sValueName
If RegCreateKeyEx(hLocation, Trim$(sSubKeys, "\"), 0, "", 0, %KEY_WRITE, ByVal %Null, hKey, ByVal %Null) = %ERROR_SUCCESS Then
' Set length of data...
dwSize = Len(sData)
'dwType = %REG_SZ
dwType = %REG_BINARY
If RegSetValueEx(hKey, zRegName, 0, dwType, ByVal StrPtr(sData), dwSize) = %ERROR_SUCCESS Then Function = %True
RegCloseKey hKey
End If
End Function

Function PBMain () As Long

hData$=Chr$(&H40)& Chr$(&H18)& Chr$(0)& Chr$(0)& Chr$(0)& Chr$(&H46)& Chr$(&HC4)

If SetReg(%HKEY_LOCAL_MACHINE, "SYSTEM\Setup", "test", hData$) Then
STDOUT "Success"
Else
STDOUT "Error"
End If

End Function

There is now no need for zRegVal.

[Alan Clarke]

Your coding worked beautiful!

David,
Thanks so much for the fix. It not only works but it is beautiful in form compared to the mess of unused variables I had before. I'm quite inexperienced in this but the love of Powerbasic's small and independent exe's is what drives me. If you are ever in the Evansville, IN area, please drop by for a visit. Being ancestorially linked to England (see my last name), I love watching Brit, Ian Wright, on "Globe Trekker" travel videos here in the U.S.

Alan Clarke
www.atechworld.com

[Michael Mattias]

> If you are ever in the Evansville, IN area

The wood furniture capital of the world, right?

(I was there about 20 years ago).

UPDATE:

No , that's wrong... I flew into Evansville on my WAY to the wood furniture capital of the world: Jasper, IN

[Fred Buffington]

I have a similar situation but different senario.

my 2.8 ghz emachines windows XP i use to call into a clients, running a non-windows OS. when printing HP PCL raster graphics on my hp deskjet it works
fine.

At the client. One of the users is using the same terminal emulation software on a direct connect, with the same printer settings. The computer is a Compaq ~3ghz win XP. When the pcl raster graphics are sent to it, it loses the chr$(0) s or at least most of them making the raster graphic strings the wrong length and resulting in garbage. I ended up changing all chr$(0) to chr$(1) which will get me by though some 'shading' is noticeable on some graphics.

I just don't understand why the same settings (WinPrint > Text) all rest pretty standard would cause this difference. I have tried different printers so it's not the printer but the way the 2 computers handle the strings or streams sent. I've been up for 36 hours approx -- it's got me frustrated.

Just to clear things up -- both win computers are acting as terminals to the remote Operating system.

[David Roberts]

Thanks Alan. Now that you have it working you may like to consider treating zRegName in a similar manner and remove the restriction of a fixed length string and have another unused variable.

Added: Since a null will not be in the value name it can go through BYREF but it will be advisable to add Chr$(0)to the RegSetValueEx parameter.

[Hubert Brandel]

Hi David,

you have used a ASCIIZ variable. This type of String will use all chars from left until a chr$(0) ($NULL) is comming. The RegSetValue() function waits for a pointer and a length. This is what I read in Win32 Programmer's Referenz. So it might be wrong defined in the Win32Api.inc - but it will work if the last parameter cbData has the right len of needed chars.

I think your code failed in this line:

dwSize = Len(sData)

AS STRING: cData = "123"+$null+"456" -> len(cData) -> 7
AS ASCIIZ: sData = "123"+$null+"456" -> len(sData) -> 3

[David Roberts]

Hubert, you have Alan's and my code mixed up.

Alan's code failed because of dwSize = LEN(zRegVal)

[Hubert Brandel]

Hubert, you have Alan's and my code mixed up.
Alan's code failed because of dwSize = LEN(zRegVal)

not only the code, sorry for that.