a libuv evented tcp client

libuv-tcp-client.c

#include <stdio.h>
#include <uv.h>

static void on_close(uv_handle_t* handle);
static void on_connect(uv_connect_t* req, int status);
static void on_write(uv_write_t* req, int status);

static uv_loop_t *loop;

static uv_buf_t alloc_cb(uv_handle_t* handle, size_t size) {
  return uv_buf_init(malloc(size), size);
}

void on_close(uv_handle_t* handle)
{
  printf("closed.");
}

void on_write(uv_write_t* req, int status)
{
  if (status) {
    uv_err_t err = uv_last_error(loop);
    fprintf(stderr, "uv_write error: %s\n", uv_strerror(err));
		return;
  }
	printf("wrote.\n");
	//uv_close((uv_handle_t*)req->handle, on_close);
}

void on_read(uv_stream_t* tcp, ssize_t nread, uv_buf_t buf)
{
	if(nread >= 0) {
		//printf("read: %s\n", tcp->data);
		printf("read: %s\n", buf.base);
	}
	else {
		//we got an EOF
    uv_close((uv_handle_t*)tcp, on_close);
	}

	//cargo-culted
	free(buf.base);
}

void on_connect(uv_connect_t* connection, int status)
{
	printf("connected.\n");

	uv_stream_t* stream = connection->handle;

	uv_buf_t buffer[] = {
		{.base = "hello", .len = 5},
		{.base = "world", .len = 5}
	};

	uv_write_t request;

	uv_write(&request, stream, buffer, 2, on_write);
	uv_read_start(stream, alloc_cb, on_read);
}


int main(int argc, char **argv) {
	loop = uv_default_loop();

	uv_tcp_t socket;
	uv_tcp_init(loop, &socket);
	uv_tcp_keepalive(&socket, 1, 60);

	struct sockaddr_in dest = uv_ip4_addr("0.0.0.0", 1234);

	uv_connect_t connect;
	uv_tcp_connect(&connect, &socket, dest, on_connect);
	
  uv_run(loop, UV_RUN_DEFAULT);
}

Local request objects in dangling in the callback, since they are not available in the callback's context.

@arijitvt is right, should have malloc a uv_write_t and free it in on_write callback.