Linux下socket双向通信

linux下的socket与windows下的类似，就是少一个初始化的过程。

服务端                         客户端

1 创建socket            1 创建socket

2 绑定                        2 连接

3 监听

4 接受

发送与接受消息，客户端与服务端都是用的recv与send，在使用完成后记得close，以释放端口资源。

下面是服务端

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <unistd.h>#include <iostream>using namespace std;#include <pthread.h>void* receiveMsg(void *sock){    char buffer[4096];    int* socket = (int*)sock;    while (1) {        memset(buffer,0,sizeof(buffer));        ssize_t byteCount = recv(*socket, buffer, 4096, 0);    if(byteCount <= 0)        {            continue;        }        cout << "recv:" <<buffer << endl;    }}void* sendMsg(void* sock){    while (1) {        usleep(500);        char buffer[4096];        memset(buffer, 0, sizeof(buffer));        cin >> buffer;        if(strlen(buffer) < 0)        {            continue;        }        ssize_t byteCount = send(*(int*)sock, buffer, 4096, 0);        if(byteCount < 0)        {            cout << "send failed" << endl;        }    }}int main(){    pthread_t sendPthread;    pthread_t recvPthread;    in_port_t servPort = 7777;    int servSock;    if ((servSock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)//创建socket    {        cout << "socket error" << endl;    }    struct sockaddr_in servAddr;    memset(&servAddr, '\0', sizeof(struct sockaddr_in));    servAddr.sin_family = AF_INET;    servAddr.sin_addr.s_addr = htonl(INADDR_ANY);//让系统自动填充地址，不用自己去查明本机的地址是多少    servAddr.sin_port = htons(servPort);    if(bind(servSock, (struct sockaddr*)&servAddr, sizeof(servAddr)) < 0) //把套接字绑定到指定的地址与端口    {        cout << "bind error" << endl;    }    if(listen(servSock, 5)< 0)//开始监听，等待客户端的连接，listen调用之前，客户端无法连接到服务端，第二个参数为最大连接数    {        cout << "listen filed" << endl;    }    struct sockaddr_in clntAddr;    socklen_t clntAddrLen = sizeof(clntAddr);    int clntSock = accept(servSock, (struct sockaddr*)&clntAddr, &clntAddrLen);    if (clntSock < 0)    {        cout << "accept error" << endl;    }    char clntName[1024];    if (inet_ntop(AF_INET, &clntAddr.sin_addr.s_addr, clntName, sizeof(clntName)) != NULL) {        cout << "Handling client: " << clntName << " port: " << ntohs(clntAddr.sin_port) << endl;;    } else {        cout << "client address get failed " << endl;    }    pthread_create(&sendPthread, NULL, sendMsg, &clntSock);    pthread_create(&recvPthread, NULL, receiveMsg, &clntSock);    pthread_join(sendPthread, 0);    pthread_join(recvPthread, 0);}

下面是客户端

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <unistd.h>#include <iostream>using namespace std;void* sendMsg(void * socket){    int sock = *((int*)socket);    while (1) {        char msg[4096];        memset(msg, 0, sizeof(msg));        cin >> msg;        size_t outputlength = strlen(msg);        if (0 == outputlength)        {            continue;        }        ssize_t bytecount = send(sock, msg, outputlength, 0);//发送消息        if (bytecount < 0) {            cout << "send failed" << endl;        }    }}void* recvMsg(void * socket){    int sock = *((int*)socket);    while (1) {        char msg[4096];        memset(msg, 0, sizeof(msg));        ssize_t bytecount = recv(sock, msg, sizeof(msg), 0); //接收消息        if (bytecount <= 0) {            continue;        } else {            cout << "recv:" << msg << endl;        }    }}int main(){    pthread_t recv;    pthread_t send;    char ipaddr[14] = "127.0.0.1";    int port = 7777;    int sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);//AF_INET指明使用ipv4，sock_stream指定使用流套接字，ipproto_tcp指定使用tcp协议    if (sock < 0) {        cout << "socket() failed" << endl;    }    struct sockaddr_in servAddr;//结构体用于存放地址    memset(&servAddr, '\0', sizeof(struct sockaddr_in));    servAddr.sin_family = AF_INET;    int rtn = inet_pton(AF_INET, ipaddr, &servAddr.sin_addr.s_addr);//转换ip地址格式，从本机字节序转换成为网络字节序    if (rtn == 0) {        cout << "address wrong ,inet_pton() failed" << endl;    } else if (rtn < 0) {        cout << "inet_pton() failed" << endl;    }    servAddr.sin_port = htons(port);    if(connect(sock, (struct sockaddr*)&servAddr, sizeof(servAddr)) < 0)//连接到服务器    {        cout << "connect failed" << endl;    }    pthread_create(&recv, NULL, recvMsg, &sock);    pthread_create(&send, NULL, sendMsg, &sock);    pthread_join(recv, 0);    pthread_join(recv, 0);    close(sock);}

注意：网络接收到的数据可能是不安全的，在使用printf等函数时要注意安全。