Function pwritev 

pub fn pwritev<Fd: AsFd>(
    fd: Fd,
    iov: &[IoSlice<'_>],
    offset: off_t,
) -> Result<usize>

Write to fd at offset from buffers in iov.

Buffers in iov will be written in order until all buffers have been written or an error occurs. The file offset is not changed.

See also: writev and pwrite