I get objectGUID data from LDAP as binary data. I need to convert ubyte[] data into a readable UUID. As far as I understand, it is possible to do this via toHexString(), but I have reached a dead end. Is there a way to make it more elegant, like this technique?

ubyte[] => [159, 199, 22, 163, 13, 74, 145, 73, 158, 112, 7, 192, 12, 193, 7, 194]
hex     => 9FC716A30D4A91499E7007C00CC107C2

On Monday, 27 March 2023 at 17:56:22 UTC, Alexander Zhirov wrote:

ubyte[] => [159, 199, 22, 163, 13, 74, 145, 73, 158, 112, 7, 192, 12, 193, 7, 194]
hex     => 9FC716A30D4A91499E7007C00CC107C2

https://run.dlang.io/is/JP01aZ

```
void main(){
    import std.stdio: writeln;
    import std.format: format;
    ubyte[] a = [159, 199, 22, 163, 13, 74, 145, 73, 158, 112, 7, 192, 12, 193, 7, 194];
    string b = format("%(%.2X%)",a);
    writeln(b);
}
```

On Monday, 27 March 2023 at 18:33:46 UTC, novice2 wrote:

```
void main(){
    import std.stdio: writeln;
    import std.format: format;
    ubyte[] a = [159, 199, 22, 163, 13, 74, 145, 73, 158, 112, 7, 192, 12, 193, 7, 194];
    string b = format("%(%.2X%)",a);
    writeln(b);
}
```

Yes, the same result. I probably didn't write my post quite correctly. I mean get the UUID data type itself. Just using this example cast(ubyte[16])ubyte[] will not work, conversion error.

On 3/27/23 1:56 PM, Alexander Zhirov wrote:

ubyte[] => [159, 199, 22, 163, 13, 74, 145, 73, 158, 112, 7, 192, 12, 193, 7, 194]
hex     => 9FC716A30D4A91499E7007C00CC107C2

auto uuid = UUID(cast(ubyte[16])youruuiddata.ptr);

-Steve

On Tuesday, 28 March 2023 at 00:51:43 UTC, Steven Schveighoffer wrote:

ubyte[] arr = cast(ubyte[])value.attributes["objectGUID"][0].dup;
writeln(UUID(cast(ubyte[16])arr.ptr));

Error: cannot cast expression 'cast(ubyte*)arr' of type 'ubyte*' to 'ubyte[16]'

No, it's not possible to transform. The array is initially immutable(char[]).

On Monday, 27 March 2023 at 18:39:19 UTC, Alexander Zhirov wrote:
I mean get the UUID data type itself. Just using

writeln(toHexString(cast(ubyte[])value.attributes["objectGUID"][0]));

When converting to HEX, I get the string 121F4C264DED5E41A33F445B0A1CAE32, in which some values are reversed. I found ways on the Internet to transform the permutation method into the desired result, but most likely it will be a crutch rather than the right solution to lead to the final result 264c1f12-ed4d-415e-a33f-445b0a1cae32.

This guid is (int,short,short,byte[8]) in little endian byte order. So if you want to convert it to big endian, you'll need to swap bytes in those int and two shorts.

ubyte[] guid=...
int* g1=cast(int*)guid.ptr;
*g1=bswap(*g1);

On Tuesday, 28 March 2023 at 05:26:08 UTC, Alexander Zhirov wrote:

So far it has been possible to convert like this

{
    writeln(value.attributes["objectGUID"][0].toUUID);
}

UUID toUUID(const char[] objectGUID)
{
    if(objectGUID.length != 16)
        throw new Exception("objectGUID does not match the length");

    auto arr = (cast(ubyte[])objectGUID).array;

    auto part1 = arr[0 .. 4].reverse;
    auto part2 = arr[4 .. 6].reverse;
    auto part3 = arr[6 .. 8].reverse;
    auto part4 = arr[8 .. 10];
    auto part5 = arr[10 .. $];

    string hex =
        toHexString(part1) ~ '-' ~
        toHexString(part2) ~ '-' ~
        toHexString(part3) ~ '-' ~
        toHexString(part4) ~ '-' ~
        toHexString(part5);

    return cast(UUID)hex;
}

On Tuesday, 28 March 2023 at 08:15:03 UTC, Alexander Zhirov wrote:

The idea was borrowed from here.

On Tuesday, 28 March 2023 at 05:05:58 UTC, Alexander Zhirov wrote:

Here is the working example:

import std.stdio;
import std.uuid;

void main()
{
	ubyte[] arr = [159, 199, 22, 163, 13, 74, 145, 73, 158, 112, 7, 192, 12, 193, 7, 194];
	UUID(arr[0 .. 16]).writeln;
}

You just need to take a slice of your array to guarantee that it has only 16 elements, and thus, pass it to UUID.