Similar to RtlNtPathNameToDosPathName but does not do any heap allocation.
The possible transformations are:
??\C:\Some\Path -> C:\Some\Path
??\UNC\server\share\foo -> \server\share\foo
If the path does not have the NT namespace prefix, then error.NotNtPath is returned.
Functionality is based on the ReactOS test cases found here: https://github.com/reactos/reactos/blob/master/modules/rostests/apitests/ntdll/RtlNtPathNameToDosPathName.c
path should be encoded as WTF-16LE.
Supports in-place modification (path and out may refer to the same slice).
pub fn ntToWin32Namespace(path: []const u16, out: []u16) errorpub fn ntToWin32Namespace(path: []const u16, out: []u16) error{ NameTooLong, NotNtPath }![]u16 {
if (path.len > PATH_MAX_WIDE) return error.NameTooLong;
if (!hasCommonNtPrefix(u16, path)) return error.NotNtPath;
var dest_index: usize = 0;
var after_prefix = path[4..]; // after the `\??\`
// The prefix \??\UNC\ means this is a UNC path, in which case the
// `\??\UNC\` should be replaced by `\\` (two backslashes)
const is_unc = after_prefix.len >= 4 and
eqlIgnoreCaseWtf16(after_prefix[0..3], std.unicode.utf8ToUtf16LeStringLiteral("UNC")) and
std.fs.path.PathType.windows.isSep(u16, after_prefix[3]);
const win32_len = path.len - @as(usize, if (is_unc) 6 else 4);
if (out.len < win32_len) return error.NameTooLong;
if (is_unc) {
out[0] = comptime std.mem.nativeToLittle(u16, '\\');
dest_index += 1;
// We want to include the last `\` of `\??\UNC\`
after_prefix = path[7..];
}
@memmove(out[dest_index..][0..after_prefix.len], after_prefix);
return out[0..win32_len];
}