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Diffstat (limited to 'third_party/rust/tokio-0.1.22/examples/udp-client.rs')
-rw-r--r-- | third_party/rust/tokio-0.1.22/examples/udp-client.rs | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/third_party/rust/tokio-0.1.22/examples/udp-client.rs b/third_party/rust/tokio-0.1.22/examples/udp-client.rs new file mode 100644 index 0000000000..900d3616df --- /dev/null +++ b/third_party/rust/tokio-0.1.22/examples/udp-client.rs @@ -0,0 +1,70 @@ +//! A UDP client that just sends everything it gets via `stdio` in a single datagram, and then +//! waits for a reply. +//! +//! For the reasons of simplicity data from `stdio` is read until `EOF` in a blocking manner. +//! +//! You can test this out by running an echo server: +//! +//! ``` +//! $ cargo run --example echo-udp -- 127.0.0.1:8080 +//! ``` +//! +//! and running the client in another terminal: +//! +//! ``` +//! $ cargo run --example udp-client +//! ``` +//! +//! You can optionally provide any custom endpoint address for the client: +//! +//! ``` +//! $ cargo run --example udp-client -- 127.0.0.1:8080 +//! ``` +//! +//! Don't forget to pass `EOF` to the standard input of the client! +//! +//! Please mind that since the UDP protocol doesn't have any capabilities to detect a broken +//! connection the server needs to be run first, otherwise the client will block forever. + +extern crate futures; +extern crate tokio; + +use std::env; +use std::io::stdin; +use std::net::SocketAddr; +use tokio::net::UdpSocket; +use tokio::prelude::*; + +fn get_stdin_data() -> Result<Vec<u8>, Box<std::error::Error>> { + let mut buf = Vec::new(); + stdin().read_to_end(&mut buf)?; + Ok(buf) +} + +fn main() -> Result<(), Box<std::error::Error>> { + let remote_addr: SocketAddr = env::args() + .nth(1) + .unwrap_or("127.0.0.1:8080".into()) + .parse()?; + // We use port 0 to let the operating system allocate an available port for us. + let local_addr: SocketAddr = if remote_addr.is_ipv4() { + "0.0.0.0:0" + } else { + "[::]:0" + } + .parse()?; + let socket = UdpSocket::bind(&local_addr)?; + const MAX_DATAGRAM_SIZE: usize = 65_507; + socket + .send_dgram(get_stdin_data()?, &remote_addr) + .and_then(|(socket, _)| socket.recv_dgram(vec![0u8; MAX_DATAGRAM_SIZE])) + .map(|(_, data, len, _)| { + println!( + "Received {} bytes:\n{}", + len, + String::from_utf8_lossy(&data[..len]) + ) + }) + .wait()?; + Ok(()) +} |