TCP服务器/客户端代码示例

TCP服务器代码：

 #include <errno.h>
 #include <string.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <iostream>

 using namespace std;

 int main(int argc, char *argv[])
 {
     if (argc != )
     {
         cout << "usage: " << argv[] << " ip port" << endl;
         return -;
     }

     char *szIp = argv[];
     in_addr_t iIp = inet_addr(szIp);
     if (iIp == INADDR_NONE)
     {
         cerr << "fail to parse ip: " << szIp << endl;
         return -;
     }
     char *pEnd = NULL;
     uint16_t usPort = strtoul(argv[], &pEnd, );
     if (*pEnd != '\0')
     {
         cerr << "fail to parse port: " << argv[] << endl;
         return -;
     }

     int iSockFd = socket(AF_INET, SOCK_STREAM, );
     if (iSockFd < )
     {
         cerr << "fail to create socket, err: " << strerror(errno) << endl;
         return -;
     }
     cout << "create socket fd " << iSockFd << endl;

     sockaddr_in oAddr;
     memset(&oAddr, , sizeof(oAddr));
     oAddr.sin_family = AF_INET;
     oAddr.sin_addr.s_addr = iIp;
     oAddr.sin_port = htons(usPort);
     if (bind(iSockFd, (sockaddr *)&oAddr, sizeof(oAddr)) < )
     {
         cerr << "fail to bind addr " << szIp << ":" << usPort << ", err: " << strerror(errno) << endl;
         return -;
     }
     cout << "bind addr " << szIp << ":" << usPort << endl;

     if (listen(iSockFd, ) < )
     {
         cerr << "fail to listen on " << szIp << ":" << usPort << ", err: " << strerror(errno) << endl;
     }
     cout << "listen on socket fd " << iSockFd << endl;

     uint8_t acRecvBuf[ * ];
     while (true)
     {
         sockaddr_in oClientAddr;
         socklen_t iAddrLen = sizeof(oClientAddr);
         int iAcceptFd = accept(iSockFd, (sockaddr *)&oClientAddr, &iAddrLen);
         if (iAcceptFd < )
         {
             cerr << "fail to accpet, err: " << strerror(errno) << endl;
             continue;
         }
         cout << "recv connection from " << inet_ntoa(oClientAddr.sin_addr) << ":" << ntohs(oClientAddr.sin_port) << endl;

         while (true)
         {
             ssize_t iRecvLen = recv(iAcceptFd, acRecvBuf, sizeof(acRecvBuf), );
             if (iRecvLen < )
             {
                 cerr << "fail to recv, close connection, err: " << strerror(errno) << endl;
                 close(iAcceptFd);
                 break;
             }
             if (iRecvLen == )
             {
                 cout << "connection closed by client" << endl;
                 close(iAcceptFd);
                 break;
             }
             cout << "recv data len: " << iRecvLen << endl;

             ssize_t iSendLen = send(iAcceptFd, acRecvBuf, iRecvLen, );
             if (iSendLen < )
             {
                 cerr << "fail to send, err: " << strerror(errno) << endl;
                 close(iAcceptFd);
                 break;
             }
             cout << "echo to client, len: " << iSendLen << endl;
         }

     }
 }

TCP客户端代码:

 #include <errno.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <stdlib.h>
 #include <iostream>

 using namespace std;

 int main(int argc, char *argv[])
 {
     if (argc != )
     {
         cout << "usage: " << argv[] << " ip port message" << endl;
         return -;
     }

     char *szIp = argv[];
     in_addr_t iIp = inet_addr(szIp);
     if (iIp == INADDR_NONE)
     {
         cerr << "fail to parse ip: " << szIp << endl;
         return -;
     }
     char *pEnd = NULL;
     uint16_t usPort = strtoul(argv[], &pEnd, );
     if (*pEnd != '\0')
     {
         cerr << "fail to parse port: " << argv[] << endl;
         return -;
     }
     char *szMsg = argv[];
     size_t uiMsgLen = strlen(szMsg);

     int iSockFd = socket(AF_INET, SOCK_STREAM, );
     if (iSockFd < )
     {
         cerr << "fail to create socket, err: " << strerror(errno) << endl;
         return -;
     }
     cout << "create socket fd " << iSockFd << endl;

     sockaddr_in oServerAddr;
     memset(&oServerAddr, , sizeof(oServerAddr));
     oServerAddr.sin_family = AF_INET;
     oServerAddr.sin_addr.s_addr = iIp;
     oServerAddr.sin_port = htons(usPort);
     if (connect(iSockFd, (sockaddr *)&oServerAddr, sizeof(oServerAddr)) < )
     {
         cerr << "fail to connect to " << szIp << ":" << usPort << ", err: " << strerror(errno) << endl;
         return -;
     }
     cout << "connect to " << szIp << ":" << usPort << endl;

     ssize_t iSendLen = send(iSockFd, szMsg, uiMsgLen, );
     if (iSendLen < )
     {
         cerr << "fail to send, err: " << strerror(errno) << endl;
         return -;
     }
     cout << "send len: " << iSendLen << ", msg: " << szMsg << endl;

     char szRecvBuf[ * ];
     char *pRecvBuf = szRecvBuf;
     size_t uiBufLen = sizeof(szRecvBuf);
     size_t uiRecvTotal = ;
     while (uiRecvTotal < iSendLen)
     {
         ssize_t iRecvLen = recv(iSockFd, pRecvBuf, uiBufLen, );
         if (iRecvLen < )
         {
             cerr << "fail to recv, close connection, err: " << strerror(errno) << endl;
             close(iSockFd);
             return -;
         }
         if (iRecvLen == )
         {
             cout << "connection closed by server" << endl;
             close(iSockFd);
             break;
         }
         pRecvBuf += iRecvLen;
         uiBufLen -= iRecvLen;
         uiRecvTotal += iRecvLen;
     }
     szRecvBuf[uiRecvTotal] = '\0';
     cout << "recv len: " << uiRecvTotal << ", msg: " << szRecvBuf << endl;
     close(iSockFd);

     return ;
 }