Linux-Tcp-IP

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

 #define DEFAULT_PORT 8800

 int main(int argc, char** argv)
 {
     int cPort = DEFAULT_PORT;
     int cClient = ;
     int cLen = ;
     struct sockaddr_in cli;
     char cbuf[] = {};

     if(argc < )
     {
         printf("Uasge: client[server IP address]\n");
         return -;
     }

     memset(cbuf, , sizeof(cbuf));

     cli.sin_family = AF_INET;
     cli.sin_port = htons(cPort);
     cli.sin_addr.s_addr = inet_addr(argv[]);

     cClient = socket(AF_INET, SOCK_STREAM, );
     if(cClient < )
     {
         printf("socket() failure!\n");
         return -;
     }

     if(connect(cClient, (struct sockaddr*)&cli, sizeof(cli)) < )
     {
         printf("connect() failure!\n");
         return -;
     }

     cLen = recv(cClient, cbuf, sizeof(cbuf),);
     if((cLen < )||(cLen == ))
     {
           printf("recv() failure!\n");
         return -;
     }
     printf("recv() Data From Server: [%s]\n", cbuf);

     close(cClient);

     return ;
 }

 //编译代码：gcc -o tcp_clt  client_tcp.c

 //执行命令：./tcp_clt 192.168.0.230

 //TCP scoket服务端程序代码

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

 /*********************************************************************
 *filename: tcpserver.c
 *purpose:tcp服务端程序
 ********************************************************************/
 int main(int argc, char ** argv)
 {
     int sockfd,new_fd;　　　　 /* 监听socket: sock_fd,数据传输socket: new_fd */
     struct sockaddr_in my_addr; /* 本机地址信息 */
     struct sockaddr_in their_addr; /* 客户地址信息 */
     unsigned int sin_size, myport, lisnum; 

     if(argv[])  myport = atoi(argv[]);
     else myport = ; 

     if(argv[])  lisnum = atoi(argv[]);
     else lisnum = ; 

     if ((sockfd = socket(PF_INET, SOCK_STREAM, )) == -) {
         perror("socket");
         exit();
     }
  printf("socket %d ok \n",myport);

     my_addr.sin_family=PF_INET;
     my_addr.sin_port=htons(myport);
     my_addr.sin_addr.s_addr = INADDR_ANY;
     bzero(&(my_addr.sin_zero), );
     if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -) {
         perror("bind");
         exit();
     }
  printf("bind ok \n");

     if (listen(sockfd, lisnum) == -) {
         perror("listen");
         exit();
     }
  printf("listen ok \n");

  /*
     while(1) {
         sin_size = sizeof(struct sockaddr_in);
         if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size)) == -1) {
             perror("accept");
             continue;
         }

         printf("server: got connection from %s\n",inet_ntoa(their_addr.sin_addr));
         if (!fork()) { //子进程代码段
             if (send(new_fd, "Hello, world!\n", 14, 0) == -1) {
                 perror("send");
                 close(new_fd);
                 exit(0);
             }
         }
         close(new_fd); //父进程不再需要该socket
         waitpid(-1,NULL,WNOHANG);//等待子进程结束，清除子进程所占用资源
     }
  */

     sin_size = sizeof(struct sockaddr_in);
     if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size)) == -) {
         perror("accept");
   exit();
     }
     printf("server: got connection from %s\n",inet_ntoa(their_addr.sin_addr));

  int   step = ;
  while() {
   char  szSnd[] = {};
   sprintf(szSnd,"i am server [%d]\n",step);
   step++;
         if (send(new_fd, szSnd, strlen(szSnd), ) == -) {
             perror("send");
             close(new_fd);
             break;
         }

   printf("send msg: %s \n",szSnd);

   sleep();
  }

  exit();
 }
 }

 //编译指令：gcc -o tcp_srv tcpserver.c 

 //执行服务器端程序：./tcp_srv

 //创建成功，绑定端口成功，监听成功后，循环发送i am server字符串。