C++ 的websocket的开发实例

#!/bin/sh
# wget http://git.warmcat.com/cgi-bin/cgit/libwebsockets/snapshot/libwebsockets-1.4-chrome43-firefox-36.tar.gz
# tar xvzf libwebsockets-1.4-chrome43-firefox-36.tar.gz
#cd libwebsockets-1.4-chrome43-firefox-36
 
# build
git clone https://github.com/warmcat/libwebsockets.git
cd libwebsockets
documentRoot=`pwd`
mkdir build
cmake ..
make
 

./libwebsockets-test-server

这样就是完整的结果了。

搭建自己的websocket server

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <libwebsockets.h>
 
#define KGRN "\033[0;32;32m"
#define KCYN "\033[0;36m"
#define KRED "\033[0;32;31m"
#define KYEL "\033[1;33m"
#define KMAG "\033[0;35m"
#define KBLU "\033[0;32;34m"
#define KCYN_L "\033[1;36m"
#define RESET "\033[0m"
 
static int destroy_flag = 0;
 
static void INT_HANDLER(int signo) {
    destroy_flag = 0;
}
 
/* *
 * websocket_write_back: write the string data to the destination wsi.
 */
int websocket_write_back(struct lws *wsi_in, char *str, int str_size_in) 
{
    if (str == NULL || wsi_in == NULL)
        return -1;
 
    int n;
    int len;
    unsigned char *out = NULL;
 
    if (str_size_in < 1) 
        len = strlen(str);
    else
        len = str_size_in;
 
    out = (unsigned char *)malloc(sizeof(unsigned char)*(LWS_SEND_BUFFER_PRE_PADDING + len + LWS_SEND_BUFFER_POST_PADDING));
    //* setup the buffer*/
    memcpy (out + LWS_SEND_BUFFER_PRE_PADDING, str, len );
    //* write out*/
    n = lws_write(wsi_in, out + LWS_SEND_BUFFER_PRE_PADDING, len, LWS_WRITE_TEXT);
 
    printf(KBLU"[websocket_write_back] %s\n"RESET, str);
    //* free the buffer*/
    free(out);
 
    return n;
}
 
 
static int ws_service_callback(
                         struct lws *wsi,
                         enum lws_callback_reasons reason, void *user,
                         void *in, size_t len)
{
 
    switch (reason) {
 
        case LWS_CALLBACK_ESTABLISHED:
            printf(KYEL"[Main Service] Connection established\n"RESET);
            break;
 
        //* If receive a data from client*/
        case LWS_CALLBACK_RECEIVE:
            printf(KCYN_L"[Main Service] Server recvived:%s\n"RESET,(char *)in);
 
            //* echo back to client*/
            websocket_write_back(wsi ,(char *)in, -1);
 
            break;
    case LWS_CALLBACK_CLOSED:
            printf(KYEL"[Main Service] Client close.\n"RESET);
        break;
 
    default:
            break;
    }
 
    return 0;
}
 
struct per_session_data {
    int fd;
};
 
int main(void) {
    // server url will usd port 5000
    int port = 5000;
    const char *interface = NULL;
    struct lws_context_creation_info info;
    struct lws_protocols protocol;
    struct lws_context *context;
    // Not using ssl
    const char *cert_path = NULL;
    const char *key_path = NULL;
    // no special options
    int opts = 0;
 
 
    //* register the signal SIGINT handler */
    struct sigaction act;
    act.sa_handler = INT_HANDLER;
    act.sa_flags = 0;
    sigemptyset(&act.sa_mask);
    sigaction( SIGINT, &act, 0);
 
    //* setup websocket protocol */
    protocol.name = "my-echo-protocol";
    protocol.callback = ws_service_callback;
    protocol.per_session_data_size=sizeof(struct per_session_data);
    protocol.rx_buffer_size = 0;
 
    //* setup websocket context info*/
    memset(&info, 0, sizeof info);
    info.port = port;
    info.iface = interface;
    info.protocols = &protocol;
    info.extensions = lws_get_internal_extensions();
    info.ssl_cert_filepath = cert_path;
    info.ssl_private_key_filepath = key_path;
    info.gid = -1;
    info.uid = -1;
    info.options = opts;
 
    //* create libwebsocket context. */
    context = lws_create_context(&info);
    if (context == NULL) {
        printf(KRED"[Main] Websocket context create error.\n"RESET);
        return -1;
    }
 
    printf(KGRN"[Main] Websocket context create success.\n"RESET);
 
    //* websocket service */
    while ( !destroy_flag ) {
        lws_service(context, 50);
    }
    usleep(10);
    lws_context_destroy(context);
 
    return 0;
}
执行脚本:

#!/bin/sh
libdir=libwebsockets
 
g++ -g -o <span style="font-family:Arial, Helvetica, sans-serif;">ws_server  </span><span style="font-family:Arial, Helvetica, sans-serif;">test_ws_server.cpp -I$libdir/lib -I$libdir/build -L$libdir/build/lib -lwebsockets</span>

编写自己的websocket client
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <pthread.h>
#include <libwebsockets.h>
 
#define KGRN "\033[0;32;32m"
#define KCYN "\033[0;36m"
#define KRED "\033[0;32;31m"
#define KYEL "\033[1;33m"
#define KBLU "\033[0;32;34m"
#define KCYN_L "\033[1;36m"
#define KBRN "\033[0;33m"
#define RESET "\033[0m"
 
static int destroy_flag = 0;
static int connection_flag = 0;
static int writeable_flag = 0;
 
static void INT_HANDLER(int signo) {
    destroy_flag = 0;
}
 
struct session_data {
    int fd;
};
 
struct pthread_routine_tool {
    struct lws_context *context;
    struct lws *wsi;
};
 
static int websocket_write_back(struct lws *wsi_in, char *str, int str_size_in) 
{
    if (str == NULL || wsi_in == NULL)
        return -1;
 
    int n;
    int len;
    unsigned char *out = NULL;
 
    if (str_size_in < 1) 
        len = strlen(str);
    else
        len = str_size_in;
 
    out = (unsigned char *)malloc(sizeof(unsigned char)*(LWS_SEND_BUFFER_PRE_PADDING + len + LWS_SEND_BUFFER_POST_PADDING));
    //* setup the buffer*/
    memcpy (out + LWS_SEND_BUFFER_PRE_PADDING, str, len );
    //* write out*/
    n = lws_write(wsi_in, out + LWS_SEND_BUFFER_PRE_PADDING, len, LWS_WRITE_TEXT);
 
    printf(KBLU"[websocket_write_back] %s\n"RESET, str);
    //* free the buffer*/
    free(out);
 
    return n;
}
 
 
static int ws_service_callback(
                         struct lws *wsi,
                         enum lws_callback_reasons reason, void *user,
                         void *in, size_t len)
{
 
    switch (reason) {
 
        case LWS_CALLBACK_CLIENT_ESTABLISHED:
            printf(KYEL"[Main Service] Connect with server success.\n"RESET);
            connection_flag = 1;
            break;
 
        case LWS_CALLBACK_CLIENT_CONNECTION_ERROR:
            printf(KRED"[Main Service] Connect with server error.\n"RESET);
            destroy_flag = 1;
            connection_flag = 0;
            break;
 
        case LWS_CALLBACK_CLOSED:
            printf(KYEL"[Main Service] LWS_CALLBACK_CLOSED\n"RESET);
            destroy_flag = 1;
            connection_flag = 0;
            break;
 
        case LWS_CALLBACK_CLIENT_RECEIVE:
            printf(KCYN_L"[Main Service] Client recvived:%s\n"RESET, (char *)in);
 
            if (writeable_flag)
                destroy_flag = 1;
 
            break;
        case LWS_CALLBACK_CLIENT_WRITEABLE :
            printf(KYEL"[Main Service] On writeable is called. send byebye message\n"RESET);
            websocket_write_back(wsi, "Byebye! See you later", -1);
            writeable_flag = 1;
            break;
 
        default:
            break;
    }
 
    return 0;
}
 
static void *pthread_routine(void *tool_in)
{
    struct pthread_routine_tool *tool = (struct pthread_routine_tool*)tool_in;
 
    printf(KBRN"[pthread_routine] Good day. This is pthread_routine.\n"RESET);
 
    //* waiting for connection with server done.*/
    while(!connection_flag)
        usleep(1000*20);
 
    //*Send greeting to server*/
    printf(KBRN"[pthread_routine] Server is ready. send a greeting message to server.\n"RESET); 
    websocket_write_back(tool->wsi, "Good day", -1);
 
    printf(KBRN"[pthread_routine] sleep 2 seconds then call onWritable\n"RESET);
    sleep(1);
    printf(KBRN"------------------------------------------------------\n"RESET);
    sleep(1);
    //printf(KBRN"[pthread_routine] sleep 2 seconds then call onWritable\n"RESET);
 
    //*involked wriable*/
    printf(KBRN"[pthread_routine] call on writable.\n"RESET);   
    lws_callback_on_writable(tool->wsi);
 
}
 
int main(void)
{
    //* register the signal SIGINT handler */
    struct sigaction act;
    act.sa_handler = INT_HANDLER;
    act.sa_flags = 0;
    sigemptyset(&act.sa_mask);
    sigaction( SIGINT, &act, 0);
 
 
    struct lws_context *context = NULL;
    struct lws_context_creation_info info;
    struct lws *wsi = NULL;
    struct lws_protocols protocol;
 
    memset(&info, 0, sizeof info);
    info.port = CONTEXT_PORT_NO_LISTEN;
    info.iface = NULL;
    info.protocols = &protocol;
    info.ssl_cert_filepath = NULL;
    info.ssl_private_key_filepath = NULL;
    info.extensions = lws_get_internal_extensions();
    info.gid = -1;
    info.uid = -1;
    info.options = 0;
 
    protocol.name  = "my-echo-protocol";
    protocol.callback = &ws_service_callback;
    protocol.per_session_data_size = sizeof(struct session_data);
    protocol.rx_buffer_size = 0;
    protocol.id = 0;
    protocol.user = NULL;
 
    context = lws_create_context(&info);
    printf(KRED"[Main] context created.\n"RESET);
 
    if (context == NULL) {
        printf(KRED"[Main] context is NULL.\n"RESET);
        return -1;
    }
 
 
wsi = lws_client_connect(context, "localhost", 5000, 0,

"/", "localhost:5000", NULL, protocol.name, -1); if (wsi == NULL) { printf(KRED"[Main] wsi create error.\n"RESET); return -1; } printf(KGRN"[Main] wsi create success.\n"RESET); struct pthread_routine_tool tool; tool.wsi = wsi; tool.context = context; pthread_t pid; pthread_create(&pid, NULL, pthread_routine, &tool); pthread_detach(pid); while(!destroy_flag) { lws_service(context, 50); } lws_context_destroy(context); return 0; } 编写脚本:
#!/bin/sh
libdir=libwebsockets
 
g++ -g -o ws_client test_ws_client.cpp -I$libdir/lib -I$libdir/build -L$libdir/build/lib -lwebsockets -lpthread

运行结果

红线部分是交互的结果.这样就是完整的一套逻辑了
--------------------- 
作者：ruoshui13 
来源：CSDN 
原文：https://blog.csdn.net/yuanwei1314/article/details/76228495 
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