On 2020-01-29 15:22, Trey Harris wrote:
On Wed, Jan 29, 2020 at 17:52 ToddAndMargo via perl6-users <perl6-us...@perl.org <mailto:perl6-us...@perl.org>> wrote:On 2020-01-29 14:20, Trey Harris wrote: > I don’t care about IpData or ValueData—those are completely unremarkable > fields. Showing me more code relating to them—or any other fields > besides cData—isn’t helpful to understanding how the 3-bytes UTF + null > cData field works. hi Trey, I think what I am missing is your "3-bytes UTF + null" question. It is only four bytes long when addressed as a REG_DWORD (32 bit unsigned integer). There is no nul at the end. The bounds are 0x0..0xFFFF_FFFF. No boxing allowed $cbData = 4; If your are addressing is as a REG_SZ (registry string), it can be as many bytes as you want when. You just have to terminate it with a 0x0000 $cbData = $lpData.elems * 2; # words are two bytes long Does that help?Could you show the API definition again, please? The copy I see says that field is a `DWORD cbData`. I don’t see the “as many bytes as you want when. You just have to terminate it with a 0x0000” part of the definition. Could you highlight it?
https://docs.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regsetvalueexw lpData The data to be stored. For string-based types, such as REG_SZ, the string must be null-terminated. cbData The size of the information pointed to by the lpData parameter, in bytes. If the data is of type REG_SZ, REG_EXPAND_SZ, or REG_MULTI_SZ, cbData must include the size of the terminating null character or characters. Any better?
