Function nc::readv

pub fn readv(fd: i32, iov: &mut [iovec_t]) -> Result<ssize_t, Errno>

Read from a file descriptor into multiple buffers.

let path = "/etc/passwd";
let ret = nc::open(path, nc::O_RDONLY, 0);
assert!(ret.is_ok());
let fd = ret.unwrap();
let mut buf = [[0_u8; 64]; 4];
let capacity = 4 * 64;
let mut iov = Vec::with_capacity(buf.len());
for ref mut item in (&mut buf).iter() {
// TODO(Shaohua): Replace with as_mut_ptr()
    iov.push(nc::iovec_t {
        iov_len: item.len(),
        iov_base: item.as_ptr() as usize,
    });
}
let ret = nc::readv(fd, &mut iov);
assert!(ret.is_ok());
assert_eq!(ret, Ok(capacity as nc::ssize_t));
assert!(nc::close(fd).is_ok());