socket多人聊天程序C語言版(一)
本文實例為大家分享了C語言實現(xiàn)socket多人聊天程序的第一篇,供大家參考,具體內(nèi)容如下
首先,不要一步登天直接解決多人聊天這個問題,先把問題化簡。
1.多人聊天的核心問題是服務器如何標識不同的客戶端,如何根據(jù)客戶端的需求轉(zhuǎn)發(fā)消息給指定客戶端。
2.多人聊天轉(zhuǎn)化為C-C聊天,但是不再是直接C-C,而是通過server轉(zhuǎn)發(fā)消息,所以變成==>C-S-C。
3.server如何允許2個client同時連接,設置listen函數(shù)的第二個參數(shù),最大連接數(shù)。
4.server如何標識兩個client,用一個結(jié)構(gòu)體數(shù)組來存放兩個client的信息。
5.server如何轉(zhuǎn)發(fā)消息給client,很簡單,先接收到的發(fā)送給還沒接收到的。如圖:

6.server如何管理兩個client的連接狀態(tài),連接成功很簡單,就是accpet成功后就是連接成功了。但是怎么判斷連接斷開呢?這個涉及到的select函數(shù)的使用,有點復雜~,所以我就簡單的用了一個send函數(shù)發(fā)送一個空消息來判斷是否斷開連接,這個不嚴謹,容易出BUG,但是實踐起來簡單就使用了它。
7.要用線程來管理接收消息、發(fā)送消息、接受請求、管理連接狀態(tài)。
技術(shù)要點:C語言線程函數(shù)的使用。
_beginthreadex函數(shù)原型 _ACRTIMP uintptr_t __cdecl _beginthreadex ( _In_opt_ void* _Security,//安全屬性,NULL為默認安全屬性 _In_ unsigned _StackSize,//線程堆棧的大小。如果為0,則線程堆棧大小和創(chuàng)建它的線程的相同。一般用0 _In_ _beginthreadex_proc_type _StartAddress, //線程函數(shù)的地址 _In_opt_ void* _ArgList, //傳進線程的函數(shù) _In_ unsigned _InitFlag, //線程初始狀態(tài),0:立即運行;CREATE_SUSPEND:懸掛(如果出事狀態(tài)定義為懸掛,就要調(diào)用ResumeThread(HANDLE) 來激活線程的運行) _Out_opt_ unsigned* _ThrdAddr //用于記錄線程ID的地址 )
例子:
#include <process.h>
#include <stdio.h>
unsigned __stdcall Thread(void* param)
{
printf("%d\n", *(int*)param); //這里必須先要強行轉(zhuǎn)換為int*,不然void* 直接解引用會出錯。
return 0;
}
int main()
{
int i = 0;
_beginthreadex(NULL, 0, Thread, &i, 0, NULL);
return 0;
}
1V1,C-S-C聊天例子:
編寫環(huán)境:win10,VS2015
效果圖:



server code:
#include <WinSock2.h>
#include <process.h>
#include <stdio.h>
#include <stdlib.h>
#pragma comment(lib,"ws2_32.lib")
#define SEND_OVER 1 //已經(jīng)轉(zhuǎn)發(fā)消息
#define SEND_YET 0 //還沒轉(zhuǎn)發(fā)消息
int g_iStatus = SEND_YET;
SOCKET g_ServerSocket = INVALID_SOCKET; //服務端套接字
SOCKADDR_IN g_ClientAddr = { 0 }; //客戶端地址
int g_iClientAddrLen = sizeof(g_ClientAddr);
bool g_bCheckConnect = false; //檢查連接情況
HANDLE g_hRecv1 = NULL;
HANDLE g_hRecv2 = NULL;
//客戶端信息結(jié)構(gòu)體
typedef struct _Client
{
SOCKET sClient; //客戶端套接字
char buf[128]; //數(shù)據(jù)緩沖區(qū)
char userName[16]; //客戶端用戶名
char IP[20]; //客戶端IP
UINT_PTR flag; //標記客戶端,用來區(qū)分不同的客戶端
}Client;
Client g_Client[2] = { 0 }; //創(chuàng)建一個客戶端結(jié)構(gòu)體
//發(fā)送數(shù)據(jù)線程
unsigned __stdcall ThreadSend(void* param)
{
int ret = 0;
int flag = *(int*)param;
SOCKET client = INVALID_SOCKET; //創(chuàng)建一個臨時套接字來存放要轉(zhuǎn)發(fā)的客戶端套接字
char temp[128] = { 0 }; //創(chuàng)建一個臨時的數(shù)據(jù)緩沖區(qū),用來存放接收到的數(shù)據(jù)
memcpy(temp, g_Client[!flag].buf, sizeof(temp));
sprintf(g_Client[flag].buf, "%s: %s", g_Client[!flag].userName, temp);//添加一個用戶名頭
if (strlen(temp) != 0 && g_iStatus == SEND_YET) //如果數(shù)據(jù)不為空且還沒轉(zhuǎn)發(fā)則轉(zhuǎn)發(fā)
ret = send(g_Client[flag].sClient, g_Client[flag].buf, sizeof(g_Client[flag].buf), 0);
if (ret == SOCKET_ERROR)
return 1;
g_iStatus = SEND_OVER; //轉(zhuǎn)發(fā)成功后設置狀態(tài)為已轉(zhuǎn)發(fā)
return 0;
}
//接受數(shù)據(jù)
unsigned __stdcall ThreadRecv(void* param)
{
SOCKET client = INVALID_SOCKET;
int flag = 0;
if (*(int*)param == g_Client[0].flag) //判斷是哪個客戶端發(fā)來的消息
{
client = g_Client[0].sClient;
flag = 0;
}
else if (*(int*)param == g_Client[1].flag)
{
client = g_Client[1].sClient;
flag = 1;
}
char temp[128] = { 0 }; //臨時數(shù)據(jù)緩沖區(qū)
while (1)
{
memset(temp, 0, sizeof(temp));
int ret = recv(client, temp, sizeof(temp), 0); //接收數(shù)據(jù)
if (ret == SOCKET_ERROR)
continue;
g_iStatus = SEND_YET; //設置轉(zhuǎn)發(fā)狀態(tài)為未轉(zhuǎn)發(fā)
flag = client == g_Client[0].sClient ? 1 : 0; //這個要設置,否則會出現(xiàn)自己給自己發(fā)消息的BUG
memcpy(g_Client[!flag].buf, temp, sizeof(g_Client[!flag].buf));
_beginthreadex(NULL, 0, ThreadSend, &flag, 0, NULL); //開啟一個轉(zhuǎn)發(fā)線程,flag標記著要轉(zhuǎn)發(fā)給哪個客戶端
//這里也可能是導致CPU使用率上升的原因。
}
return 0;
}
//管理連接
unsigned __stdcall ThreadManager(void* param)
{
while (1)
{
if (send(g_Client[0].sClient, "", sizeof(""), 0) == SOCKET_ERROR)
{
if (g_Client[0].sClient != 0)
{
CloseHandle(g_hRecv1); //這里關(guān)閉了線程句柄,但是測試結(jié)果斷開連C/S接后CPU仍然瘋漲
CloseHandle(g_hRecv2);
printf("Disconnect from IP: %s,UserName: %s\n", g_Client[0].IP, g_Client[0].userName);
closesocket(g_Client[0].sClient); //這里簡單的判斷:若發(fā)送消息失敗,則認為連接中斷(其原因有多種),關(guān)閉該套接字
g_Client[0] = { 0 };
}
}
if (send(g_Client[1].sClient, "", sizeof(""), 0) == SOCKET_ERROR)
{
if (g_Client[1].sClient != 0)
{
CloseHandle(g_hRecv1);
CloseHandle(g_hRecv2);
printf("Disconnect from IP: %s,UserName: %s\n", g_Client[1].IP, g_Client[1].userName);
closesocket(g_Client[1].sClient);
g_Client[1] = { 0 };
}
}
Sleep(2000); //2s檢查一次
}
return 0;
}
//接受請求
unsigned __stdcall ThreadAccept(void* param)
{
int i = 0;
int temp1 = 0, temp2 = 0;
_beginthreadex(NULL, 0, ThreadManager, NULL, 0, NULL);
while (1)
{
while (i < 2)
{
if (g_Client[i].flag != 0)
{
++i;
continue;
}
//如果有客戶端申請連接就接受連接
if ((g_Client[i].sClient = accept(g_ServerSocket, (SOCKADDR*)&g_ClientAddr, &g_iClientAddrLen)) == INVALID_SOCKET)
{
printf("accept failed with error code: %d\n", WSAGetLastError());
closesocket(g_ServerSocket);
WSACleanup();
return -1;
}
recv(g_Client[i].sClient, g_Client[i].userName, sizeof(g_Client[i].userName), 0); //接收用戶名
printf("Successfuuly got a connection from IP:%s ,Port: %d,UerName: %s\n",
inet_ntoa(g_ClientAddr.sin_addr), htons(g_ClientAddr.sin_port), g_Client[i].userName);
memcpy(g_Client[i].IP, inet_ntoa(g_ClientAddr.sin_addr), sizeof(g_Client[i].IP)); //記錄客戶端IP
g_Client[i].flag = g_Client[i].sClient; //不同的socke有不同UINT_PTR類型的數(shù)字來標識
i++;
}
i = 0;
if (g_Client[0].flag != 0 && g_Client[1].flag != 0) //當兩個用戶都連接上服務器后才進行消息轉(zhuǎn)發(fā)
{
if (g_Client[0].flag != temp1) //每次斷開一個連接后再次連上會新開一個線程,導致cpu使用率上升,所以要關(guān)掉舊的
{
if (g_hRecv1) //這里關(guān)閉了線程句柄,但是測試結(jié)果斷開連C/S接后CPU仍然瘋漲
CloseHandle(g_hRecv1);
g_hRecv1 = (HANDLE)_beginthreadex(NULL, 0, ThreadRecv, &g_Client[0].flag, 0, NULL); //開啟2個接收消息的線程
}
if (g_Client[1].flag != temp2)
{
if (g_hRecv2)
CloseHandle(g_hRecv2);
g_hRecv2 = (HANDLE)_beginthreadex(NULL, 0, ThreadRecv, &g_Client[1].flag, 0, NULL);
}
}
temp1 = g_Client[0].flag; //防止ThreadRecv線程多次開啟
temp2 = g_Client[1].flag;
Sleep(3000);
}
return 0;
}
//啟動服務器
int StartServer()
{
//存放套接字信息的結(jié)構(gòu)
WSADATA wsaData = { 0 };
SOCKADDR_IN ServerAddr = { 0 }; //服務端地址
USHORT uPort = 18000; //服務器監(jiān)聽端口
//初始化套接字
if (WSAStartup(MAKEWORD(2, 2), &wsaData))
{
printf("WSAStartup failed with error code: %d\n", WSAGetLastError());
return -1;
}
//判斷版本
if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2)
{
printf("wVersion was not 2.2\n");
return -1;
}
//創(chuàng)建套接字
g_ServerSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (g_ServerSocket == INVALID_SOCKET)
{
printf("socket failed with error code: %d\n", WSAGetLastError());
return -1;
}
//設置服務器地址
ServerAddr.sin_family = AF_INET;//連接方式
ServerAddr.sin_port = htons(uPort);//服務器監(jiān)聽端口
ServerAddr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);//任何客戶端都能連接這個服務器
//綁定服務器
if (SOCKET_ERROR == bind(g_ServerSocket, (SOCKADDR*)&ServerAddr, sizeof(ServerAddr)))
{
printf("bind failed with error code: %d\n", WSAGetLastError());
closesocket(g_ServerSocket);
return -1;
}
//設置監(jiān)聽客戶端連接數(shù)
if (SOCKET_ERROR == listen(g_ServerSocket, 20000))
{
printf("listen failed with error code: %d\n", WSAGetLastError());
closesocket(g_ServerSocket);
WSACleanup();
return -1;
}
_beginthreadex(NULL, 0, ThreadAccept, NULL, 0, 0);
for (int k = 0;k < 100;k++) //讓主線程休眠,不讓它關(guān)閉TCP連接.
Sleep(10000000);
//關(guān)閉套接字
for (int j = 0;j < 2;j++)
{
if (g_Client[j].sClient != INVALID_SOCKET)
closesocket(g_Client[j].sClient);
}
closesocket(g_ServerSocket);
WSACleanup();
return 0;
}
int main()
{
StartServer(); //啟動服務器
return 0;
}
client code:
#define _WINSOCK_DEPRECATED_NO_WARNINGS
#include <WinSock2.h>
#include <process.h>
#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#pragma comment(lib,"ws2_32.lib")
#define RECV_OVER 1
#define RECV_YET 0
char userName[16] = { 0 };
int iStatus = RECV_YET;
//接受數(shù)據(jù)
unsigned __stdcall ThreadRecv(void* param)
{
char buf[128] = { 0 };
while (1)
{
int ret = recv(*(SOCKET*)param, buf, sizeof(buf), 0);
if (ret == SOCKET_ERROR)
{
Sleep(500);
continue;
}
if (strlen(buf) != 0)
{
printf("%s\n", buf);
iStatus = RECV_OVER;
}
else
Sleep(100);
}
return 0;
}
//發(fā)送數(shù)據(jù)
unsigned __stdcall ThreadSend(void* param)
{
char buf[128] = { 0 };
int ret = 0;
while (1)
{
int c = getch();
if(c == 72 || c == 0 || c == 68)//為了顯示美觀,加一個無回顯的讀取字符函數(shù)
continue; //getch返回值我是經(jīng)過實驗得出如果是返回這幾個值,則getch就會自動跳過,具體我也不懂。
printf("%s: ", userName);
gets_s(buf);
ret = send(*(SOCKET*)param, buf, sizeof(buf), 0);
if (ret == SOCKET_ERROR)
return 1;
}
return 0;
}
//連接服務器
int ConnectServer()
{
WSADATA wsaData = { 0 };//存放套接字信息
SOCKET ClientSocket = INVALID_SOCKET;//客戶端套接字
SOCKADDR_IN ServerAddr = { 0 };//服務端地址
USHORT uPort = 18000;//服務端端口
//初始化套接字
if (WSAStartup(MAKEWORD(2, 2), &wsaData))
{
printf("WSAStartup failed with error code: %d\n", WSAGetLastError());
return -1;
}
//判斷套接字版本
if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2)
{
printf("wVersion was not 2.2\n");
return -1;
}
//創(chuàng)建套接字
ClientSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (ClientSocket == INVALID_SOCKET)
{
printf("socket failed with error code: %d\n", WSAGetLastError());
return -1;
}
//輸入服務器IP
printf("Please input server IP:");
char IP[32] = { 0 };
gets_s(IP);
//設置服務器地址
ServerAddr.sin_family = AF_INET;
ServerAddr.sin_port = htons(uPort);//服務器端口
ServerAddr.sin_addr.S_un.S_addr = inet_addr(IP);//服務器地址
printf("connecting......\n");
//連接服務器
if (SOCKET_ERROR == connect(ClientSocket, (SOCKADDR*)&ServerAddr, sizeof(ServerAddr)))
{
printf("connect failed with error code: %d\n", WSAGetLastError());
closesocket(ClientSocket);
WSACleanup();
return -1;
}
printf("Connecting server successfully IP:%s Port:%d\n",
IP, htons(ServerAddr.sin_port));
printf("Please input your UserName: ");
gets_s(userName);
send(ClientSocket, userName, sizeof(userName), 0);
printf("\n\n");
_beginthreadex(NULL, 0, ThreadRecv, &ClientSocket, 0, NULL); //啟動接收和發(fā)送消息線程
_beginthreadex(NULL, 0, ThreadSend, &ClientSocket, 0, NULL);
for (int k = 0;k < 1000;k++)
Sleep(10000000);
closesocket(ClientSocket);
WSACleanup();
return 0;
}
int main()
{
ConnectServer(); //連接服務器
return 0;
}
這程序還有一些BUG,其中最大的就是關(guān)掉一個連接后CPU使用率瘋漲,我測試過我想到的可能,還是找不到結(jié)果~,希望有大神懂的告知一下。
下篇請點擊socket多人聊天程序C語言版(二)
以上就是本文的全部內(nèi)容,希望對大家的學習有所幫助,也希望大家多多支持腳本之家。
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