[Raspberry] TCP/IP 傳輸之 server/client 程式

Socket 在哪邊:

TCP:

UDP:

hostaddress 由4 byte的數字組成,socket中的struct in_addr 將這個整束包裝起來,定義在in.h

struct in_addr {

__be32    s_addr;

}

特殊的host address number:

l   INADDR_LOOPBACK:指本機的address,也就是127.0,0,1(localhost)

l   INADDR_ANY:指任何連上來的address

l   INADDR_BROADCAST:傳送broadcast訊息才可使用

l   INADDR_NONE:某些function錯誤時的回傳值

字節順序轉換函數：

htonl():把32位值從主機字節序轉換成網絡字節序

htons():把16位值從主機字節序轉換成網絡字節序

ntohl():把32位值從網絡字節序轉換成主機字節序

ntohs():把16位值從網絡字節序轉換成主機字節序

Bind函數將socket與本機上的一個埠相關聯.你就可以在該埠監聽服務請求

Client端:

#include <cstdlib>

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

using namespace std;

/*
 *
 */
int main(int argc, char** argv) {

    int sockfd=0,n=0;
    char recvBuff[1024];
    struct sockaddr_in serv_addr;
   
    if(argc!=2)
    {
        printf("\n Usage:%s <ip of server> \n",argv[0]);
        return 1;
    }
   
    memset(recvBuff,'0',sizeof(recvBuff));
   
    if((sockfd=socket(AF_INET,SOCK_STREAM,0))<0)
    {
        printf("\n Error: Could not create socket \n");
        return 1;
    }
   
    memset(&serv_addr,'0',sizeof(serv_addr));
   
    serv_addr.sin_family=AF_INET;
   
    serv_addr.sin_port=htons(5000);
   
    if(inet_pton(AF_INET,argv[1],&serv_addr.sin_addr)<=0)
    {
        printf("\n inet_pton error occured\n");
        return 1;
    }
   
    if(connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr))<0)
    {
        printf("\n Error:Connect Failed \n");
        return 1;
    }
   
   
    while((n=read(sockfd,recvBuff,sizeof(recvBuff)-1))>0)
    {
        recvBuff[n]=0;
        if(fputs(recvBuff,stdout)==EOF)
        {
            printf("\n Error:Fputs error \n");
        }
    }
   
    if(n<0)
    {
        printf("\n Read error\n");
    }
 
    return 0;
}



SERVER端:
#include <cstdlib>

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

using namespace std;

/*
 *
 */

int main(int argc, char** argv) {

    int listenfd=0,connfd=0;
   
    struct sockaddr_in serv_addr;
   
    char sendBuff[1025];
   
    time_t ticks;
   
    listenfd=socket(AF_INET,SOCK_STREAM,0);

    memset(&serv_addr,'0',sizeof(serv_addr));
   
    memset(sendBuff,'0',sizeof(sendBuff));
   
    serv_addr.sin_family=AF_INET;
   
    serv_addr.sin_addr.s_addr=htonl(INADDR_ANY);
   
    serv_addr.sin_port=htons(5000);
   
    bind(listenfd,(struct sockaddr*)&serv_addr,sizeof(serv_addr));
   
    listen(listenfd,10);
   
    while(1)
    {
        connfd=accept(listenfd,(struct sockaddr *)NULL,NULL);
       
        ticks=time(NULL);
       
        snprintf(sendBuff,sizeof(sendBuff),"%.24s\r\n",ctime(&ticks));
               
        write(connfd,sendBuff,strlen(sendBuff));
       
        close(connfd);
       
        sleep(1);
    } 
    return 0;
}



 

參考:

http://www.thegeekstuff.com/2011/12/c-socket-programming/