doc: add code samples from uvbook (unadapted)

PR-URL: https://github.com/libuv/libuv/pull/1246
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/docs/code/tcp-echo-server/main.c b/docs/code/tcp-echo-server/main.c
new file mode 100644
index 00000000..63965bd9
--- /dev/null
+++ b/docs/code/tcp-echo-server/main.c
@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <uv.h>
+
+#define DEFAULT_PORT 7000
+#define DEFAULT_BACKLOG 128
+
+uv_loop_t *loop;
+struct sockaddr_in addr;
+
+typedef struct {
+    uv_write_t req;
+    uv_buf_t buf;
+} write_req_t;
+
+void free_write_req(uv_write_t *req) {
+    write_req_t *wr = (write_req_t*) req;
+    free(wr->buf.base);
+    free(wr);
+}
+
+void alloc_buffer(uv_handle_t *handle, size_t suggested_size, uv_buf_t *buf) {
+    buf->base = (char*) malloc(suggested_size);
+    buf->len = suggested_size;
+}
+
+void echo_write(uv_write_t *req, int status) {
+    if (status) {
+        fprintf(stderr, "Write error %s\n", uv_strerror(status));
+    }
+    free_write_req(req);
+}
+
+void echo_read(uv_stream_t *client, ssize_t nread, const uv_buf_t *buf) {
+    if (nread > 0) {
+        write_req_t *req = (write_req_t*) malloc(sizeof(write_req_t));
+        req->buf = uv_buf_init(buf->base, nread);
+        uv_write((uv_write_t*) req, client, &req->buf, 1, echo_write);
+        return;
+    }
+    if (nread < 0) {
+        if (nread != UV_EOF)
+            fprintf(stderr, "Read error %s\n", uv_err_name(nread));
+        uv_close((uv_handle_t*) client, NULL);
+    }
+
+    free(buf->base);
+}
+
+void on_new_connection(uv_stream_t *server, int status) {
+    if (status < 0) {
+        fprintf(stderr, "New connection error %s\n", uv_strerror(status));
+        // error!
+        return;
+    }
+
+    uv_tcp_t *client = (uv_tcp_t*) malloc(sizeof(uv_tcp_t));
+    uv_tcp_init(loop, client);
+    if (uv_accept(server, (uv_stream_t*) client) == 0) {
+        uv_read_start((uv_stream_t*) client, alloc_buffer, echo_read);
+    }
+    else {
+        uv_close((uv_handle_t*) client, NULL);
+    }
+}
+
+int main() {
+    loop = uv_default_loop();
+
+    uv_tcp_t server;
+    uv_tcp_init(loop, &server);
+
+    uv_ip4_addr("0.0.0.0", DEFAULT_PORT, &addr);
+
+    uv_tcp_bind(&server, (const struct sockaddr*)&addr, 0);
+    int r = uv_listen((uv_stream_t*) &server, DEFAULT_BACKLOG, on_new_connection);
+    if (r) {
+        fprintf(stderr, "Listen error %s\n", uv_strerror(r));
+        return 1;
+    }
+    return uv_run(loop, UV_RUN_DEFAULT);
+}