MPI_File_iwrite(3) on Linux
The text 4bd196d865e0, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy) shipped it.
Nonblocking write using individual file pointer