回射程序改进1

原回射程序

回射程序改良，将源main函数中的某些操作定义为单独的函数，使其便于修改

chat_cli.c 文件

  1 #include "net.h"
  2 
  3 int main(int argc, char **argv)
  4 {
  5     int sockfd;
  6 
  7     if (argc != 2)
  8     {
  9         printf("Error arg!\n");
 10         exit(1);
 11     }
 12     sockfd = tcp_connect(argv[1], SERV_PORT);
 13     printf("Success init!\n");
 14     cli_io(sockfd);
 15 
 16     return 0;
 17 }

fun_cli.c 文件

  1 #include "net.h"
  2 
  3 // 建立一个TCP套接字(IPv4)，并与给定主机端口连接，并返回连接后的套接字
  4 int tcp_connect(char *ser_ip, int port)
  5 {
  6     int sockfd;
  7     struct sockaddr_in servaddr;
  8 
  9     if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0 )
 10     {
 11         printf("Error socket!\n");
 12         exit(1);
 13     }
 14 
 15     bzero(&servaddr, sizeof(servaddr));
 16     servaddr.sin_family = AF_INET;
 17     servaddr.sin_port = htons(port);
 18 
 19     if (inet_pton(AF_INET, ser_ip, &servaddr.sin_addr) <= 0)
 20     {
 21         printf("Error inet_pton!\n");
 22         exit(1);
 23     }
 24 
 25     if (connect(sockfd, (SA *) &servaddr, sizeof(servaddr)) < 0)
 26     {
 27         printf("Error connect!\n");
 28         exit(1);
 29     }
 30 
 31     return sockfd;
 32 }
 33 
 34 // 回射程序客户端对套接字的读写
 35 void cli_io(int sockfd)
 36 {
 37     int n;
 38     char sendline[MAXLINE], recvline[MAXLINE];
 39 
 40     while (fgets(sendline, MAXLINE, stdin) != NULL)
 41     {
 42         if (write(sockfd, sendline, strlen(sendline)) < 0)
 43         {
 44             printf("Error write!\n");
 45             exit(1);
 46         }
 47 
 48         if ( (n = read(sockfd, recvline, MAXLINE)) > 0 )
 49         {
 50             recvline[n] = '\0';
 51             fputs(recvline, stdout);
 52         }
 53     }
 54 
 55     return;
 56 }

chat_serv.c 文件

  1 #include "net.h"
  2 
  3 int main(int argc, char **argv)
  4 {
  5     int listenfd, connfd, n;
  6     struct cliaddr;
  7     pid_t childpid;
  8     socklen_t clilen;
  9     
 10     listenfd = tcp_listen(SERV_PORT);
 11     
 12     for ( ; ; )
 13     {   
 14         clilen = sizeof(cliaddr);
 15         
 16         if ( (connfd = accept(listenfd, (SA *) &cliaddr, &clilen)) < 0 )
 17         {   
 18             printf("Error accept!\n");
 19             exit(0);
 20         }
 21         
 22         if ( (childpid = fork()) == 0 )
 23         {   
 24             if (close(listenfd) < 0)
 25             {   
 26                 printf("Error close!\n");
 27                 exit(1);
 28             }
 29             
 30             serv_io(connfd);
 31             exit(0);
 32         }
 33     }
 34 }

fun_serv.c文件

  1 #include "net.h"
  2 
  3 // 创建一个tcp套接字，并在指定端口上监听
  4 int tcp_listen(int port)
  5 {
  6     int listenfd;
  7     struct sockaddr_in servaddr;
  8 
  9     if ( (listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0 )
 10     {
 11         printf("Error socket!\n");
 12         exit(1);
 13     }
 14 
 15     bzero(&servaddr, sizeof(servaddr));
 16     servaddr.sin_family = AF_INET;
 17     servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
 18     servaddr.sin_port = htons(port);
 19 
 20     if (bind(listenfd, (SA *) &servaddr, sizeof(servaddr)) < 0)
 21     {
 22         printf("Error bind!\n");
 23         exit(1);
 24     }
 25 
 26     if (listen(listenfd, LISTENQ) < 0)
 27     {
 28         printf("Error listen!\n");
 29         exit(1);
 30     }
 31 
 32     return listenfd;
 33 }
 34 
 35 // 服务端io
 36 void serv_io(int connfd)
 37 {
 38     char buff[MAXLINE];
 39     int n;
 40 
 41     while ( (n = read(connfd, buff, MAXLINE)) > 0 )
 42     {
 43         buff[n] = '\0';
 44         fputs(buff, stdout);
 45 
 46         if (write(connfd, buff, strlen(buff)) < 0)
 47         {
 48             printf("Error write!\n");
 49             exit(1);
 50         }
 51     }
 52 
 53     return;
 54 }