recv_from

fn recv_from(Stream s, Vec<byte> buf) -> Result<(int, string, int), IoError>

use io::net::udp::{recv_from};

Receives one datagram into the front of buf without waiting.

Returns (n, host, port): the number of bytes written to buf[0..n] and the sender’s IP address (IPv6 without brackets) and port. A datagram longer than buf.len() is cut to fit; the rest is lost. Returns Err(IoError::WouldBlock) when no datagram is waiting; then call wait_readable(s) and retry, or use io::sync::recv_from_wait. An empty buf returns (0, "", 0) at once. Needs no permission flag (the grant is checked at bind).

Parameters#

Returns#

Result<(int, string, int), IoError>

Examples#

use io::{wait_readable, IoError};
use io::net::udp::{bind, local_port, recv_from, send_to};
use string::{to_bytes};
use tests::assert;
fn run() -> Result<(int, string, int), IoError> {
    let server = bind("127.0.0.1", 0)?;
    let port = local_port(server)?;
    let client = bind("127.0.0.1", 0)?;
    send_to(client, to_bytes("hi"), "127.0.0.1", port)?;
    wait_readable(server)?;
    return recv_from(server, to_bytes("........"))?;
}

fn main() {
    let (n, host, port) = match run() {
        Result::Ok(t) => t,
        Result::Err(_) => (0, "", 0),
    };
    assert!(n == 2 && host == "127.0.0.1" && port > 0);
}

See also#

• io::sync::recv_from_wait
• io::net::udp::bind
• connect: Opens a UDP socket whose default peer is host on port.
• local_port: Returns the local port a UDP socket is bound to.
• send_to: Sends buf as one datagram to host on port and returns how many bytes were sent.