Synchronous file IO in Lua?

[Tomas Mudrunka <mudrunka@...>]

Hello,
i have Lua script on Linux that opens file handle using io.open(),
writes to it using :write() and closes it using :close().

I really need way to call fsync() on that file descriptor.
https://man7.org/linux/man-pages/man2/fsync.2.html

Either as an argument, eg.: file:write(true) file:close(true)
or as separate call file:sync(). Is there way to do that?
If not, can you see this being added in the future?

I know as a workaround i can call os.execute("sync");
But that triggers system wide sync of all files and filesystems, which 
is not really desirable.

--
S pozdravem
Best regards
     Tomáš Mudruňka