Linux c 通过TCP协议实现多个客户端连接服务器

通过父子进程实现TCP的多个客户端连接服务器 
tcp_sever_fork.c

#include <stdio.h>  #include <string.h>  #include <stdlib.h>  #include <sys/types.h>  #include <sys/socket.h>  #include <errno.h>  #include <arpa/inet.h>  #define PORT 3333  int main()  {      int sockfd;      int sock_fd;      struct sockaddr_in server_addr;      struct sockaddr_in client_addr;      int addrlen = sizeof(struct sockaddr);      int addrinlen = sizeof(struct sockaddr_in);      int recvbytes;      char buf[1024];      //服务器创建套接字      if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)      {          fprintf(stderr, "socket error:%s\n", strerror(errno));      exit(1);      }      //服务器填充sockaddr结构      bzero(&server_addr, addrinlen);      server_addr.sin_family = AF_INET;      //server_addr.sin_addr.s_addr = htonl(INADDR_ANY);//INADDR_ANY表示可以接收任意IP地址的数据，即绑定所有的IP      server_addr.sin_addr.s_addr = inet_addr("192.168.1.222");//用于绑定到一个固定的IP，inet_addr用于把数字加格式的IP转化为整形IP      server_addr.sin_port = htons(PORT);      //绑定socket到IP地址      if(bind(sockfd, (struct sockaddr *)&server_addr, addrlen) < 0)      {          fprintf(stderr, "bind error:%s\n", strerror(errno));      exit(1);      }      //设置允许连接的最大客户端数目      if(listen(sockfd, 5) < 0)      {          fprintf(stderr, "listen error:%s\n", strerror(errno));      exit(1);      }      while(1)      {          //建立连接      if((sock_fd = accept(sockfd, (struct sockaddr *)&client_addr, &addrinlen)) < 0)      {              fprintf(stderr, "accept error:%s\n", strerror(errno));          exit(1);      }          if(fork() == 0)      {          if((recvbytes = recv(sock_fd, buf, 1024, 0)) < 0)          {                  fprintf(stderr, "recv error:%s\n", strerror(errno));              exit(1);           }              buf[recvbytes] = '\0';              printf("buf is %s\n", buf);          close(sockfd);          close(sock_fd);          exit(0);      }      else      {          //通讯结束              close(sock_fd);      }      }      //关闭      close(sockfd);      return 0;  }  
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tcp_client_fork.c

#include <stdio.h>  #include <string.h>  #include <stdlib.h>  #include <sys/types.h>  #include <sys/socket.h>  #include <errno.h>  #include <arpa/inet.h>  #define PORT 3333  int main()  {      int sockfd;      struct sockaddr_in server_addr;      int addrlen = sizeof(struct sockaddr);      int addrinlen = sizeof(struct sockaddr_in);      char buf[512];      char buf1[1024];      //客户端程序创建套接字      if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)      {          fprintf(stderr, "socket error:%s\n", strerror(errno));      exit(1);      }      //客户端程序填充服务器的资料      bzero(&server_addr, addrlen);//初始化，置0      server_addr.sin_family = AF_INET;//IPv4      //server_addr.sin_addr.s_addr = htonl(INADDR_ANY);//      server_addr.sin_addr.s_addr = inet_addr("192.168.1.222");      server_addr.sin_port = htons(PORT);//将本机的short数据转化为网络上的short数据——端口号      //服务器发起连接请求      if(connect(sockfd, (struct sockaddr *)&server_addr, addrlen) < 0)      {          fprintf(stderr, "bind error:%s\n", strerror(errno));      exit(1);      }      //while(1)      //{      //连接成功      printf("Please input:\n");      fgets(buf, 512, stdin);      //发送数据      if(send(sockfd, buf, 512, 0) < 0)      {          fprintf(stderr, "listen error:%s\n", strerror(errno));      close(sockfd);      exit(1);      }      //write(sockfd, buf, strlen(buf));      #if 0      memset(buf1, 0, sizeof(buf1));      if(read(sockfd, buf1, sizeof(buf1)) < 0)      {          fprintf(stderr, "listen error:%s\n", strerror(errno));      exit(1);      }      printf("read is %s\n", buf1);      #endif     // }      //关闭套接字      close(sockfd);      return 0;  }  
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运行结果：