stat

pub fn stat(self: File) StatError!Stat {
    if (builtin.os.tag == .windows) {
        var io_status_block: windows.IO_STATUS_BLOCK = undefined;
        var info: windows.FILE_ALL_INFORMATION = undefined;
        const rc = windows.ntdll.NtQueryInformationFile(self.handle, &io_status_block, &info, @sizeOf(windows.FILE_ALL_INFORMATION), .FileAllInformation);
        switch (rc) {
            .SUCCESS => {},
            // Buffer overflow here indicates that there is more information available than was able to be stored in the buffer
            // size provided. This is treated as success because the type of variable-length information that this would be relevant for
            // (name, volume name, etc) we don't care about.
            .BUFFER_OVERFLOW => {},
            .INVALID_PARAMETER => unreachable,
            .ACCESS_DENIED => return error.AccessDenied,
            else => return windows.unexpectedStatus(rc),
        }
        return .{
            .inode = info.InternalInformation.IndexNumber,
            .size = @as(u64, @bitCast(info.StandardInformation.EndOfFile)),
            .mode = 0,
            .kind = if (info.BasicInformation.FileAttributes & windows.FILE_ATTRIBUTE_REPARSE_POINT != 0) reparse_point: {
                var tag_info: windows.FILE_ATTRIBUTE_TAG_INFO = undefined;
                const tag_rc = windows.ntdll.NtQueryInformationFile(self.handle, &io_status_block, &tag_info, @sizeOf(windows.FILE_ATTRIBUTE_TAG_INFO), .FileAttributeTagInformation);
                switch (tag_rc) {
                    .SUCCESS => {},
                    // INFO_LENGTH_MISMATCH and ACCESS_DENIED are the only documented possible errors
                    // https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-fscc/d295752f-ce89-4b98-8553-266d37c84f0e
                    .INFO_LENGTH_MISMATCH => unreachable,
                    .ACCESS_DENIED => return error.AccessDenied,
                    else => return windows.unexpectedStatus(rc),
                }
                if (tag_info.ReparseTag & windows.reparse_tag_name_surrogate_bit != 0) {
                    break :reparse_point .sym_link;
                }
                // Unknown reparse point
                break :reparse_point .unknown;
            } else if (info.BasicInformation.FileAttributes & windows.FILE_ATTRIBUTE_DIRECTORY != 0)
                .directory
            else
                .file,
            .atime = windows.fromSysTime(info.BasicInformation.LastAccessTime),
            .mtime = windows.fromSysTime(info.BasicInformation.LastWriteTime),
            .ctime = windows.fromSysTime(info.BasicInformation.ChangeTime),
        };
    }

    if (builtin.os.tag == .wasi and !builtin.link_libc) {
        const st = try std.os.fstat_wasi(self.handle);
        return Stat.fromWasi(st);
    }

    if (builtin.os.tag == .linux) {
        var stx = std.mem.zeroes(linux.Statx);

        const rc = linux.statx(
            self.handle,
            "",
            linux.AT.EMPTY_PATH,
            linux.STATX_TYPE | linux.STATX_MODE | linux.STATX_ATIME | linux.STATX_MTIME | linux.STATX_CTIME,
            &stx,
        );

        return switch (linux.E.init(rc)) {
            .SUCCESS => Stat.fromLinux(stx),
            .ACCES => unreachable,
            .BADF => unreachable,
            .FAULT => unreachable,
            .INVAL => unreachable,
            .LOOP => unreachable,
            .NAMETOOLONG => unreachable,
            .NOENT => unreachable,
            .NOMEM => error.SystemResources,
            .NOTDIR => unreachable,
            else => |err| posix.unexpectedErrno(err),
        };
    }

    const st = try posix.fstat(self.handle);
    return Stat.fromPosix(st);
}