c++实现的linux下 socket通信

服务端:

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

#define ListenNum 20
#define BufLen 1024

using namespace std;

int main()
{
    int sock,sock_new;
    int buf_len;
    socklen_t sin_size=sizeof(struct sockaddr);
    int re,se;
    char * buf_r=new char [BufLen];
    char * buf_s=new char [BufLen];
    struct sockaddr_in my_addr;
    struct sockaddr_in ob_addr;

    sock=socket(AF_INET,SOCK_STREAM,0);
    if(sock==-1) {cout<<"socket error"<<endl;exit(0);}
    else {cout<<sock<<endl;}
    my_addr.sin_family=AF_INET; 
    my_addr.sin_port=htons(3490);
    my_addr.sin_addr.s_addr=INADDR_ANY;

    if(bind(sock,(struct sockaddr *)& my_addr,sizeof(struct sockaddr))<0)
    {
        cout<<"bind error"<<endl;
        exit(0);
    }
    cout<<"socket port: "<<ntohs(my_addr.sin_port)<<endl;
    if(listen(sock,ListenNum)<0)
    {
        cout<<"listen error"<<endl;
        exit(0);
    }
   
    while(1)
    {
        sock_new=accept(sock,(sockaddr *)&ob_addr,&sin_size);
        if(sock_new<0)
        {
            cout<<"accept error"<<endl;
            exit(0);
        }
        else
        {
            int p=fork();
            if(p==0)
            {
                cout<<"connect to :"<<inet_ntoa(ob_addr.sin_addr)<<" : "<<htons(ob_addr.sin_port)<<endl;
                int s=fork();
                if(s==0)
                {
                    do
                    {               
                        memset(buf_r,0,sizeof(buf_r));
                        re=recv(sock_new,buf_r,BufLen,0);

                        if(re==-1)
                        {
                            cout<<"recv error"<<endl;
                            exit(0);
                        }
                        else if(re==0)
                        {
                            cout<<inet_ntoa(ob_addr.sin_addr)<<"connection ended"<<endl;
                            close(sock_new);
                        }
                        else
                        {
                            cout<<inet_ntoa(ob_addr.sin_addr)<<" -> "<<buf_r<<endl;
                        }
                    }while(re>0);
                }
                else
                {
                    do
                    {
                        memset(buf_s,0,sizeof(buf_s));
                        cin.getline(buf_s,BufLen);
                        se=send(sock_new,buf_s,BufLen,0);
                        if(se==-1)
                        {
                            cout<<"send error"<<endl;
                            exit(0);
                        }
                        else
                        {
                            cout<<"sended!"<<endl;
                        }
                    }while(1);
                }
            }
        }
    }   
    close(sock);
    return 0;
}

客户端:

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

#define ListenNum 20
#define BufLen 1024

using namespace std;

int main()
{
   
    int sock,sock_new;
    int buf_len;
    socklen_t sin_size=sizeof(struct sockaddr);
    char * buf_s=new char [BufLen];
    char * buf_r=new char [BufLen];
    char * ip=new char [20];
    int re;
    memset(ip,0,sizeof(ip));
    struct sockaddr_in my_addr;
    struct sockaddr_in ob_addr;

    sock=socket(AF_INET,SOCK_STREAM,0);
    if(sock==-1) {cout<<"socket error"<<endl;exit(0);}
    else {cout<<sock<<endl;}

    my_addr.sin_family=AF_INET; 
    my_addr.sin_port=htons(0);
    my_addr.sin_addr.s_addr=INADDR_ANY;

    if(bind(sock,(struct sockaddr *)& my_addr,sin_size)<0)
    {
        cout<<"bind error"<<endl;
        exit(0);
    }
   
    cout<<"socket port: "<<ntohs(my_addr.sin_port)<<endl;

    cout<<"input ip : ";
    cin.getline(ip,20);
   
    ob_addr.sin_family=AF_INET;
    ob_addr.sin_addr.s_addr=inet_addr(ip);
    ob_addr.sin_port=htons(3490);

    if(connect(sock,(sockaddr *)&ob_addr,sizeof(sockaddr))<0)
    {
        cout<<"connect error"<<endl;
        exit(0);
    }
    else
    {
        cout<<"connect success"<<endl;
        int p=fork();
        if(p==0)
        {
            while(cin.getline(buf_s,BufLen))
            {
                if(send(sock,buf_s,BufLen,0)!=-1)
                    cout<<"sended!"<<endl;
                else cout<<"send error"<<endl;
            }
        }
        else
        {
            do
            {
                memset(buf_r,0,sizeof(buf_r));
                re=recv(sock,buf_r,BufLen,0);
                if(re==-1)
                {
                    cout<<"recv error"<<endl;
                    exit(0);
                }
                else if(re==0)
                {
                    cout<<inet_ntoa(ob_addr.sin_addr)<<"connection ended"<<endl;
                    close(sock);
                }
                else
                {
                    cout<<inet_ntoa(ob_addr.sin_addr)<<" -> "<<buf_r<<endl;
                }
            }while(re>0);
        }
    }
    return 0;
}

服务器测试的好例子