最近由于實驗需要，要求寫一個c程序與java程序通信的軟件，為了測試首先寫了一個windows環境下c語言的socket（tcp）通信程序。

首先socket通信的步驟：

?? 圖一???? socket通信步驟（轉載)

??????????????????????????????????????????? 圖二 三次握手協議（轉載）

? 圖三??? 三次握手協議（轉載）

代碼? 服務器端

??? #include <winsock2.h>
??? #include <windows.h>
??? #pragma comment(lib,"ws2_32.lib")
??? ?
??? int main(int argc, char* argv[])
??? {
?? ??? ?//初始化WSA
?? ??? ?WORD sockVersion = MAKEWORD(2, 2);
?? ??? ?WSADATA wsaData;
?? ??? ?if (WSAStartup(sockVersion, &wsaData) != 0)
?? ??? ?{
?? ??? ??? ?return 0;
?? ??? ?}
??? ?
?? ??? ?//創建套接字
?? ??? ?SOCKET slisten = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
?? ??? ?if (slisten == INVALID_SOCKET)
?? ??? ?{
?? ??? ??? ?printf("socket error !");
?? ??? ??? ?return 0;
?? ??? ?}
??? ?
?? ??? ?//綁定IP和端口
?? ??? ?struct sockaddr_in sin;
?? ??? ?sin.sin_family = AF_INET;
?? ??? ?sin.sin_port = htons(8888);
?? ??? ?sin.sin_addr.S_un.S_addr = INADDR_ANY;
?? ??? ?if (bind(slisten, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)
?? ??? ?{
?? ??? ??? ?printf("bind error !");
?? ??? ?}
??? ?
?? ??? ?//開始監聽
?? ??? ?if (listen(slisten, 5) == SOCKET_ERROR)
?? ??? ?{
?? ??? ??? ?printf("listen error !");
?? ??? ??? ?return 0;
?? ??? ?}
??? ?
?? ??? ?//循環接收數據
?? ??? ?SOCKET sClient;
?? ??? ?struct sockaddr_in remoteAddr;
?? ??? ?int nAddrlen = sizeof(remoteAddr);
?? ??? ?//char revData[255];
?? ??? ?printf("等待連接...\n");
?? ??? ?sClient = accept(slisten, (SOCKADDR *)&remoteAddr, &nAddrlen);
?? ??? ?while (1)
?? ??? ?{
?? ??? ??? ?char revData[255];
?? ??? ??? ?//printf("等待連接...\n");
?? ??? ??? ?//sClient = accept(slisten, (SOCKADDR *)&remoteAddr, &nAddrlen);
?? ??? ??? ?if (sClient == INVALID_SOCKET)
?? ??? ??? ?{
?? ??? ??? ??? ?printf("accept error !");
?? ??? ??? ??? ?continue;
?? ??? ??? ?}
?? ??? ??? ?printf("接受到一個連接：%s \r\n", inet_ntoa(remoteAddr.sin_addr));
??? ?
?? ??? ??? ?//接收數據
?? ??? ??? ?int ret = recv(sClient, revData, 255, 0);
?? ??? ??? ?//printf(ret);
?? ??? ??? ?if (ret > 0)
?? ??? ??? ?{
?? ??? ??? ??? ?revData[ret] = 0x00;
?? ??? ??? ??? ?printf(revData);
?? ??? ??? ?}
?? ??? ??? ?//發送數據
?? ??? ??? ?char * sendData = "你好，TCP客戶端！\n";
?? ??? ??? ?send(sClient, sendData, strlen(sendData), 0);
?? ??? ?}
?? ??? ??? ?closesocket(sClient);
?? ??? ?closesocket(slisten);
?? ??? ?WSACleanup();
?? ??? ?return 0;
??? }

代碼?? 客戶端

??? #include <winsock2.h>
??? #include <windows.h>
??? #pragma comment(lib,"ws2_32.lib")
??? #include <STDIO.H>
??? int main(int argc, char* argv[])
??? {
?? ??? ?WORD sockVersion = MAKEWORD(2, 2);
?? ??? ?WSADATA data;
?? ??? ?if (WSAStartup(sockVersion, &data) != 0)
?? ??? ?{
?? ??? ??? ?return 0;
?? ??? ?}
??? ?
?? ??? ?SOCKET sclient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
?? ??? ?if (sclient == INVALID_SOCKET)
?? ??? ?{
?? ??? ??? ?printf("invalid socket !");
?? ??? ??? ?return 0;
?? ??? ?}
??? ?
?? ??? ?struct sockaddr_in serAddr;
?? ??? ?serAddr.sin_family = AF_INET;
?? ??? ?serAddr.sin_port = htons(8888);
?? ??? ?serAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
?? ??? ?if (connect(sclient, (struct sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR)
?? ??? ?{
?? ??? ??? ?printf("connect error !");
?? ??? ??? ?closesocket(sclient);
?? ??? ??? ?return 0;
?? ??? ?}
?? ??? ?for (int i = 0; i < 1000; i++)
?? ??? ?{
??? ?
?? ??? ??? ?char * sendData = "csi接收? 二進制文件未解析\n";
?? ??? ??? ?send(sclient, sendData, strlen(sendData), 0);
?? ??? ??? ?char recData[255];
?? ??? ??? ?/*int ret = recv(sclient, recData, 255, 0);
?? ??? ??? ?if (ret > 0)
?? ??? ??? ?{
?? ??? ?
?? ??? ??? ??? ?recData[ret] = 0x00;
?? ??? ??? ??? ?//printf(recData);
?? ??? ??? ??? ?printf("%d%s",i,recData);
?? ??? ??? ?}
?? ??? ??? ?*/
?? ??? ?}
?? ??? ?closesocket(sclient);
?? ??? ?WSACleanup();
?? ??? ?return 0;
??? }

后續會給出c程序與java程序通信的例子。

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