struct lws_context* context = lws_create_context(&info);
时间: 2024-05-30 17:10:02 浏览: 11
这是一个使用libwebsockets库创建WebSocket服务器的代码片段。它调用`lws_create_context()`函数来创建一个WebSocket上下文,并将其存储在指向`struct lws_context`类型的指针变量`context`中。`&info`参数是一个指向`struct lws_context_creation_info`类型的结构体,其中包含有关WebSocket服务器的配置信息,例如端口号、协议等。
相关问题
#include <stdio.h> #include <string.h> #include <libwebsockets.h> #define BUFFER_SIZE 4096 static struct lws *wsi_client = NULL; static int callback_chat(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len) { switch (reason) { case LWS_CALLBACK_CLIENT_ESTABLISHED: // 连接建立,记录wsi_client wsi_client = wsi; break; case LWS_CALLBACK_CLIENT_RECEIVE: // 接收到服务端发来的消息,输出到控制台 printf("[Client] Message received: %s\n", (char *)in); break; case LWS_CALLBACK_CLIENT_CLOSED: // 连接关闭,设置wsi_client为NULL wsi_client = NULL; break; default: break; } return 0; } static struct lws_protocols protocols[] = { { "chat", callback_chat, 0, BUFFER_SIZE }, { NULL, NULL, 0, 0 } }; int main(int argc, char **argv) { struct lws_context_creation_info info; memset(&info, 0, sizeof(info)); info.port = CONTEXT_PORT_NO_LISTEN; info.protocols = protocols; info.gid = -1; info.uid = -1; struct lws_context *context = lws_create_context(&info); if (context == NULL) { fprintf(stderr, "Error: Failed to create libwebsocket context\n"); return -1; } struct lws_client_connect_info connect_info; memset(&connect_info, 0, sizeof(connect_info)); connect_info.context = context; connect_info.address = "localhost"; connect_info.port = 8080; connect_info.path = "/"; connect_info.host = lws_canonical_hostname(context); connect_info.origin = connect_info.host; connect_info.protocol = protocols[0].name; struct lws *wsi = lws_client_connect_via_info(&connect_info); if (wsi == NULL) { fprintf(stderr, "Error: Failed to connect to server\n"); lws_context_destroy(context); return -1; } while (wsi_client == NULL) { lws_service(context, 50); } char buffer[BUFFER_SIZE]; while (fgets(buffer, BUFFER_SIZE, stdin)) { if (wsi_client == NULL) { break; } buffer[strlen(buffer) - 1] = '\0'; lws_write(wsi_client, (unsigned char *)buffer, strlen(buffer), LWS_WRITE_TEXT); } lws_context_destroy(context); return 0; }这段代码是否有问题?
这段代码似乎没有问题,它使用libwebsockets库创建了一个WebSocket客户端,连接到本地主机的端口8080上,并在控制台上显示接收到的消息。在main函数中,先创建一个libwebsocket的上下文,然后通过connect_info结构体配置WebSocket客户端连接信息,最后使用lws_client_connect_via_info函数连接WebSocket服务器。然后使用lws_service函数在while循环中等待连接建立,等到wsi_client不为空时,就可以向服务器发送消息了。在fgets函数中获取输入的消息,使用lws_write函数将消息发送给服务器。最后使用lws_context_destroy函数销毁libwebsockets上下文。
libwebsockets domo
以下是使用 libwebsockets 实现一个简单的 WebSocket 服务器和客户端的示例:
服务器端代码:
```c
#include <libwebsockets.h>
#include <string.h>
#include <stdio.h>
static int callback_echo(struct lws *wsi, enum lws_callback_reasons reason,
void *user, void *in, size_t len)
{
switch (reason) {
case LWS_CALLBACK_ESTABLISHED: {
printf("connection established\n");
break;
}
case LWS_CALLBACK_RECEIVE: {
char buf[1024];
strncpy(buf, (char *)in, len);
buf[len] = '\0';
printf("received message: %s\n", buf);
lws_write(wsi, (unsigned char *)in, len, LWS_WRITE_TEXT);
break;
}
default:
break;
}
return 0;
}
static struct lws_protocols protocols[] = {
{
"echo-protocol",
callback_echo,
0,
1024,
},
{ NULL, NULL, 0, 0 }
};
int main(void)
{
struct lws_context_creation_info info;
memset(&info, 0, sizeof(info));
info.port = 8000;
info.protocols = protocols;
struct lws_context *context;
context = lws_create_context(&info);
if (!context) {
printf("Failed to create libwebsocket context\n");
return -1;
}
while (1) {
lws_service(context, 50);
}
lws_context_destroy(context);
return 0;
}
```
客户端代码:
```c
#include <libwebsockets.h>
#include <string.h>
#include <stdio.h>
static int callback_echo(struct lws *wsi, enum lws_callback_reasons reason,
void *user, void *in, size_t len)
{
switch (reason) {
case LWS_CALLBACK_CLIENT_ESTABLISHED: {
printf("connection established\n");
lws_write(wsi, (unsigned char *)"Hello, server!", 14, LWS_WRITE_TEXT);
break;
}
case LWS_CALLBACK_CLIENT_RECEIVE: {
char buf[1024];
strncpy(buf, (char *)in, len);
buf[len] = '\0';
printf("received message: %s\n", buf);
break;
}
default:
break;
}
return 0;
}
static struct lws_protocols protocols[] = {
{
"echo-protocol",
callback_echo,
0,
1024,
},
{ NULL, NULL, 0, 0 }
};
int main(void)
{
struct lws_context_creation_info info;
memset(&info, 0, sizeof(info));
info.port = CONTEXT_PORT_NO_LISTEN;
info.protocols = protocols;
struct lws_context *context;
context = lws_create_context(&info);
if (!context) {
printf("Failed to create libwebsocket context\n");
return -1;
}
struct lws_client_connect_info connect_info;
memset(&connect_info, 0, sizeof(connect_info));
connect_info.context = context;
connect_info.address = "localhost";
connect_info.port = 8000;
connect_info.path = "/";
connect_info.host = "localhost";
connect_info.origin = "http://localhost";
struct lws *wsi;
wsi = lws_client_connect_via_info(&connect_info);
if (!wsi) {
printf("Failed to connect to server\n");
lws_context_destroy(context);
return -1;
}
while (1) {
lws_service(context, 50);
}
lws_context_destroy(context);
return 0;
}
```
以上代码实现了一个简单的 WebSocket 服务器和客户端,服务器收到客户端发送的消息后,会将消息原样返回给客户端。