civetweb/examples/websocket/websocket.c

// Copyright (c) 2004-2012 Sergey Lyubka
// This file is a part of civetweb project, http://github.com/sunsetbrew/civetweb

#include <stdio.h>
#include <string.h>
#include "civetweb.h"

static void websocket_ready_handler(struct mg_connection *conn)
{
    static const char *message = "server ready";
    mg_websocket_write(conn, WEBSOCKET_OPCODE_TEXT, message, strlen(message));
}

// Arguments:
//   flags: first byte of websocket frame, see websocket RFC,
//          http://tools.ietf.org/html/rfc6455, section 5.2
//   data, data_len: payload data. Mask, if any, is already applied.
static int websocket_data_handler(struct mg_connection *conn, int flags,
                                  char *data, size_t data_len)
{
    (void) flags; // Unused
    mg_websocket_write(conn, WEBSOCKET_OPCODE_TEXT, data, data_len);

    // Returning zero means stoping websocket conversation.
    // Close the conversation if client has sent us "exit" string.
    return memcmp(data, "exit", 4);
}

int main(void)
{
    struct mg_context *ctx;
    struct mg_callbacks callbacks;
    const char *options[] = {
        "listening_ports", "8080",
        "document_root", "websocket_html_root",
        NULL
    };

    memset(&callbacks, 0, sizeof(callbacks));
    callbacks.websocket_ready = websocket_ready_handler;
    callbacks.websocket_data = websocket_data_handler;
    ctx = mg_start(&callbacks, NULL, options);
    getchar();  // Wait until user hits "enter"
    mg_stop(ctx);

    return 0;
}