unix网络编程1章-daytimetcpcli3.c客户端

 1 #include        "unp.h"
  2
  3 int
  4 main(int argc, char **argv)
  5 {
  6         int                                     sockfd, n;
  7         socklen_t                       len;
  8         char                            recvline[MAXLINE + 1];
  9         struct sockaddr_in      servaddr, cliaddr;
 10
 11         if (argc != 2)
 12                 err_quit("usage: a.out <IPaddress>");
 13
 14         if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
 15                 err_sys("socket error");
 16
 17         bzero(&servaddr, sizeof(servaddr));
 18         servaddr.sin_family = AF_INET;
 19         servaddr.sin_port   = htons(13);        /* daytime server */
 20         if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0)
 21                 err_quit("inet_pton error for %s", argv[1]);
 22
 23         if (connect(sockfd, (SA *) &servaddr, sizeof(servaddr)) < 0)
 24                 err_sys("connect error");
 25
 26         len = sizeof(cliaddr);
 27         Getsockname(sockfd, (SA *) &cliaddr, &len);
 28         printf("local addr: %s\n",
 29                    Sock_ntop((SA *) &cliaddr, sizeof(cliaddr)));
 30
 31         while ( (n = read(sockfd, recvline, MAXLINE)) > 0) {
 32                 recvline[n] = 0;        /* null terminate */
 33                 if (fputs(recvline, stdout) == EOF)
 34                         err_sys("fputs error");
 35         }
 36         if (n < 0)
 37                 err_sys("read error");
 38
 39         exit(0);
 40 }