manual/examples/inetcli.c

   1 #include <stdio.h>
   2 #include <errno.h>
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5 #include <sys/types.h>
   6 #include <sys/socket.h>
   7 #include <netinet/in.h>
   8 #include <netdb.h>
   9
  10 #define PORT            5555
  11 #define MESSAGE         "Yow!!! Are we having fun yet?!?"
  12 #define SERVERHOST      "mescaline.gnu.org"
  13
  14 void
  15 write_to_server (int filedes)
  16 {
  17   int nbytes;
  18
  19   nbytes = write (filedes, MESSAGE, strlen (MESSAGE) + 1);
  20   if (nbytes < 0)
  21     {
  22       perror ("write");
  23       exit (EXIT_FAILURE);
  24     }
  25 }
  26
  27
  28 int
  29 main (void)
  30 {
  31   extern void init_sockaddr (struct sockaddr_in *name,
  32                              const char *hostname,
  33                              uint16_t port);
  34   int sock;
  35   struct sockaddr_in servername;
  36
  37   /* Create the socket.  */
  38   sock = socket (PF_INET, SOCK_STREAM, 0);
  39   if (sock < 0)
  40     {
  41       perror ("socket (client)");
  42       exit (EXIT_FAILURE);
  43     }
  44
  45   /* Connect to the server.  */
  46   init_sockaddr (&servername, SERVERHOST, PORT);
  47   if (0 > connect (sock,
  48                    (struct sockaddr *) &servername,
  49                    sizeof (servername)))
  50     {
  51       perror ("connect (client)");
  52       exit (EXIT_FAILURE);
  53     }
  54
  55   /* Send data to the server.  */
  56   write_to_server (sock);
  57   close (sock);
  58   exit (EXIT_SUCCESS);
  59 }