socket基本使用

UDP发送和接收

MainRecv.cpp

#include <iostream>
#include <WinSock2.h>
#include <sstream>

#pragma comment(lib,"ws2_32.lib")

#define RECV_IP "127.0.0.1"
#define RECV_PORT 8899
#define LEN_RECV_BUF 2048

int main()
{
    std::ostringstream ossTemp;
    WSAData wsaData;

    std::cout<<"Start..."<<std::endl;

    WSAStartup(MAKEWORD(2,2),&wsaData);
    SOCKET sktRecv=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);

    sockaddr_in addrRecv;
    addrRecv.sin_family=AF_INET;
    addrRecv.sin_addr.s_addr=inet_addr(RECV_IP);
         //htonl(INADDR_ANY);
    addrRecv.sin_port=htons(RECV_PORT);

    int retVal;

    retVal=bind(sktRecv,(sockaddr*)&addrRecv,sizeof(addrRecv));

    sockaddr_in addrClient;
    char buf[LEN_RECV_BUF];
    int len=sizeof(addrClient);
    while(true)
    {
        memset(buf,0,LEN_RECV_BUF);
        retVal=recvfrom(sktRecv,buf,LEN_RECV_BUF,0,(sockaddr*)&addrClient,&len);
        if(SOCKET_ERROR==retVal)
        {
            ossTemp<<"recvfrom error : "<<retVal<<"\n";
            OutputDebugString(ossTemp.str().c_str());
            break;
        }
        if(strlen(buf)>0)
            std::cout<<buf<<std::endl;
    }

    closesocket(sktRecv);
    WSACleanup();

    std::cout<<"Recv Over"<<std::endl;
    getchar();
    return -1;
}

MainSend.cpp

#include <iostream>
#include <sstream>
#include <WinSock2.h>

#define IP_SEND "127.0.0.1"
#define PORT_SEND 8899
#define LEN_SEND_BUF 1024

#pragma comment(lib,"ws2_32.lib")

int main()
{
    WSAData wsaData;
    WSAStartup(MAKEWORD(2,2),&wsaData);

    std::cout<<"Begin Sending..."<<std::endl;

    std::ostringstream ossTemp;
    SOCKET sktSend=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
    sockaddr_in addrSend;
    addrSend.sin_family=AF_INET;
    addrSend.sin_addr.s_addr=inet_addr(IP_SEND);
    addrSend.sin_port=htons(PORT_SEND);
    int retVal;

    char buf[LEN_SEND_BUF];
    int len=sizeof(addrSend);
    int index=0;
    while(true)
    {
        if(index>255)
            break;
        ossTemp.str("");
        ossTemp<<index;
        memset(buf,0,LEN_SEND_BUF);
        memcpy(buf,ossTemp.str().c_str(),sizeof(int));
        retVal=sendto(sktSend,buf,LEN_SEND_BUF,0,(sockaddr*)&addrSend,len);
        if(SOCKET_ERROR==retVal)
        {
            ossTemp.str("");
            ossTemp<<"sendto error : "<<retVal;
            OutputDebugString( ossTemp.str().c_str() );
            break;
        }
        std::cout<<"Send : "<<buf<<std::endl;
        index++;
    }

    closesocket(sktSend);
    WSACleanup();

    std::cout<<"Send Over"<<std::endl;
    getchar();
    return 0;
}

========================

linux下socket使用备忘:

先看文件列表:

Config.h...........................................

#define SERVER_IP "192.168.6.129"
#define SERVER_PORT 12345

Makefile

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>　　//inet_addr需要引用
#include <string.h>　　//memset方法需要引用
#include <unistd.h>　　//close(sock_id)方法需要引用

#include "Config.h"

#define BUFSIZE 1024

int main(int argc,char* argv[])
{
int server_sockfd;
int client_sockfd;
int len;
struct sockaddr_in server_addr;
struct sockaddr_in client_addr;
int sin_size;
char buf[BUFSIZE];
memset(&server_addr,0,sizeof(server_addr));
server_addr.sin_family=AF_INET;
server_addr.sin_addr.s_addr=inet_addr("192.168.6.129");
//inet_pton(AF_INET,"192.168.6.129",&(server_addr.sin_addr));
server_addr.sin_port=htons(SERVER_PORT);

if( (server_sockfd=socket(AF_INET,SOCK_STREAM,0))<0 ){
perror("create sockets failed.");
return -1;
}

if( bind(server_sockfd,(struct sockaddr*)&server_addr,sizeof(struct sockaddr))<0 ){
perror("bind the socket failed.");
return -1;
}

listen(server_sockfd,5);

sin_size=sizeof(struct sockaddr_in);

if( (client_sockfd=accept(server_sockfd,(struct sockaddr*)&client_addr,(socklen_t*)&sin_size))<0 ){
perror("accept the connect failed.");
return -1;
}
printf( "accept client %s\n",inet_ntoa(client_addr.sin_addr) );
len=send(client_sockfd,"Welcome to my server\n",21,0);

while( (len=recv(client_sockfd,buf,BUFSIZE,0))>0 ){
buf[len]='\0';
printf("%s\n",buf);
if( send(client_sockfd,buf,len,0)<0 ){
perror("write failed.");
return -1;
}
}

close(client_sockfd);
close(server_sockfd);
return 0;
}

MySockTcpClient.cpp...........................................

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <unistd.h>

#include "Config.h"

#define BUFSIZE 1024

int main(int argc,char* argv[])
{
int client_sockfd;
int len;
struct sockaddr_in server_addr;
char buf[BUFSIZE];
memset(&server_addr,0,sizeof(server_addr));
server_addr.sin_family=AF_INET;
server_addr.sin_addr.s_addr=inet_addr(SERVER_IP);
//inet_pton(AF_INET,SERVER_IP,&(server_addr.sin_addr));
server_addr.sin_port=htons(SERVER_PORT);

if( (client_sockfd=socket(PF_INET,SOCK_STREAM,0))<0 ){
perror("create the socket failed.");
return -1;
}

if( connect(client_sockfd,(struct sockaddr*)&server_addr,sizeof(struct sockaddr))<0 ){
perror("connect the server failed.");
}

printf("connected to server\n");
len=recv( client_sockfd,buf,BUFSIZE,0 );
buf[len]='\0';
printf("%s",buf);

while(1){
printf("Enter string to send:");
scanf("%s",buf);
if( !strcmp(buf,"quit") )
break;
len=send(client_sockfd,buf,strlen(buf),0);
len=recv(client_sockfd,buf,BUFSIZE,0);
buf[len]='\0';
printf("received:%s\n",buf);
}

close(client_sockfd);
return 0;

}

Makefile..................................................

CC=g++
CFLAGS=-I. -g

all:MySockTcpServer MySockTcpClient

MySockTcpServer:MySockTcpServer.o
　　$(CC) -o MySockTcpServer MySockTcpServer.o -I.
MySockTcpClient:MySockTcpClient.o
　　$(CC) -o MySockTcpClient MySockTcpClient.o -I.

clean:
　　rm -f *.o MySockTcpClient MySockTcpServer

注意:

比较window,差别是:

1,头文件不同;

2,对socket的类型定义上有差别;

设置端口缓存大小:

//2. may set socket behavior 
int nErrCode;
unsigned int uiRcvBuf;
int uiRcvBufLen = sizeof(uiRcvBuf);
nErrCode= getsockopt(m_tcpClient, SOL_SOCKET, SO_RCVBUF, (char*)&uiRcvBuf, &uiRcvBufLen);
if(SOCKET_ERROR == nErrCode) return FALSE;
if(uiRcvBuf!=1024*8){
　　//uiRcvBuf *= BUF_MULTIPLE;
　　uiRcvBuf=1024*8;
　　nErrCode = setsockopt(m_tcpClient, SOL_SOCKET, SO_RCVBUF,(char*)&uiRcvBuf, uiRcvBufLen);
if (SOCKET_ERROR == nErrCode) return FALSE;

nErrCode=getsockopt(m_tcpClient, SOL_SOCKET, SO_RCVBUF,(char*)&uiRcvBuf, &uiRcvBufLen);
if (SOCKET_ERROR == nErrCode) return FALSE;
if(uiRcvBuf!=1024*8) return FALSE;
}