UDP connection example for Zig language

00_UDP_example.txt

UDP connection example for Zig language

udp_client.zig

const std = @import("std");
const os = std.os;
const log = std.log;
const time = std.time;

const UDP_PAYLOADSIZE = 65507;

fn helloToServer(ipaddr: []const u8, port: u16, verbose:bool) !void {
    var buf: [UDP_PAYLOADSIZE]u8 = .{};

    const sockfd = try os.socket(os.AF.INET, os.SOCK.DGRAM | os.SOCK.CLOEXEC, 0);
    defer os.closeSocket(sockfd);

    const addr = try std.net.Address.resolveIp(ipaddr, port);
    try os.connect(sockfd, &addr.any, addr.getOsSockLen());

    const message = "Hello Server, this is zig client";
    const send_bytes = try os.send(sockfd, message, 0);
    if (verbose) {
        log.info("{d}: send_bytes={d}", .{time.milliTimestamp(), send_bytes});
    }
    const recv_bytes = try os.recv(sockfd, buf[0..], 0);
    if (verbose) {
        log.info("{d}: recv_bytes={d}, [{s}]", .{time.milliTimestamp(), recv_bytes, buf[0..recv_bytes]});
    }
 }

pub fn main() !void {
    // TODO: get parameters from command line options
    const verbose = true;
    const port: u16 = 7200;
    const adr = "127.0.0.1";
    try helloToServer(adr, port, verbose);
}

udp_server.zig

const std = @import("std");
const os = std.os;
const log = std.log;
const time = std.time;

const UDP_PAYLOADSIZE = 65507;

fn serverLoop(port: u16) !void {
    const ip4_addr = "0.0.0.0";
    var buf: [UDP_PAYLOADSIZE]u8 = .{};

    const sockfd = try os.socket(os.AF.INET, os.SOCK.DGRAM | os.SOCK.CLOEXEC, 0);
    defer os.closeSocket(sockfd);

    const addr = try std.net.Address.resolveIp(ip4_addr, port);
    try os.bind(sockfd, &addr.any, addr.getOsSockLen());
    
    log.info("{d}: ready. port={d}", .{time.milliTimestamp(), port});
    var cliaddr: std.os.linux.sockaddr = undefined;
    var cliaddrlen: std.os.socklen_t = @sizeOf(os.linux.sockaddr);
    while (true) {
        const recv_bytes = try os.recvfrom(sockfd, buf[0..], 0, &cliaddr, &cliaddrlen);
        log.info("{d}: recv_bytes={d}, [{s}]", .{time.milliTimestamp(), recv_bytes, buf[0..recv_bytes]});
        const message = "Hi client, this is zig server.";
        const send_bytes = try os.sendto(sockfd, message, 0, &cliaddr, cliaddrlen);
        log.info("{d}: send_bytes={d}", .{time.milliTimestamp(), send_bytes});
    }
 }

pub fn main() !void {
    // TODO: get parameters from command line options
    const port: u16 = 7200;

    try serverLoop(port);
}