服務端

#include<stdio.h>
#include <sys/socket.h>
#include<string.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netinet/in.h>
#define TCP_PORT 9999

int main()
{
     char ipbuf[32];
     char recbuf[0x1000];
     int socket_ser,socket_accept;
     socket_ser = socket(AF_INET,SOCK_STREAM,0);
     struct sockaddr_in addr,addr_c;
     bzero(&addr,sizeof(addr));
     addr.sin_family = AF_INET;
     addr.sin_port = htons(TCP_PORT);
     addr.sin_addr.s_addr = htonl(INADDR_ANY);
     bind(socket_ser,(struct sockaddr *)&addr,sizeof(addr));
     listen(socket_ser,128);
     while(1)
     {

         bzero(ipbuf, sizeof(ipbuf));
         bzero(&addr_c,sizeof(addr_c));
         bzero(recbuf,sizeof(recbuf));
         int len_c;
         socket_accept = accept(socket_ser,(struct sockaddr *)&addr_c,(socklen_t *)&len_c);
         inet_ntop(AF_INET,&addr_c.sin_addr.s_addr,ipbuf,sizeof(ipbuf));
         printf("Ip is %s,port is %d\n",ipbuf,ntohs(addr_c.sin_port));
 
         int len = read(socket_accept,recbuf,sizeof(recbuf));
         printf("%s\n",recbuf);
         write(socket_accept,recbuf,len);
         close(socket_accept);
     }
     close(socket_ser);
     return 0;
 }
 

客戶端

#include<stdio.h>
#include <sys/socket.h>
#include<string.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netinet/in.h>
#define TCP_PORT 9999

int main()
{
     int socket_fd,socket_accept;
     socket_fd = socket(AF_INET,SOCK_STREAM,0);
     struct sockaddr_in addr;
     bzero(&addr,sizeof(addr));
     addr.sin_family = AF_INET;
     addr.sin_port = htons(TCP_PORT);
     inet_pton(AF_INET,"127.0.0.1",&addr.sin_addr.s_addr);
     connect(socket_fd,(struct sockaddr*)&addr,sizeof(addr));
     char bufsend[] = "hello world";
     char bufrec[0x1000];
     bzero(bufrec,sizeof(bufrec));
     write(socket_fd,bufsend,strlen(bufsend));
     read(socket_fd,bufrec,sizeof(bufrec));
     printf("%s\n",bufrec);
     close(socket_fd);
     return 0;
 }
 

沒啥知識點，需要注意的是socket_accept即是三次握手完成，用inet_ntop轉換ip要好點 inet_ntop是可重入函式