pub fn preadv(
fd: RawFd,
iov: &[IoVec<&mut [u8]>],
offset: off_t
) -> Result<usize>
Read from fd at offset filling buffers in iov.
Buffers in iov will be filled in order until all buffers have been filled,
no more bytes are available, or an error occurs. The file offset is not
changed.
See also: readv and pread