1  /* Example of Reading Datagrams
       2     Copyright (C) 1991-2023 Free Software Foundation, Inc.
       3  
       4     This program is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU General Public License
       6     as published by the Free Software Foundation; either version 2
       7     of the License, or (at your option) any later version.
       8  
       9     This program is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU General Public License for more details.
      13  
      14     You should have received a copy of the GNU General Public License
      15     along with this program; if not, see <https://www.gnu.org/licenses/>.
      16  */
      17  
      18  #include <stdio.h>
      19  #include <errno.h>
      20  #include <unistd.h>
      21  #include <stdlib.h>
      22  #include <sys/socket.h>
      23  #include <sys/un.h>
      24  
      25  #define SERVER	"/tmp/serversocket"
      26  #define CLIENT	"/tmp/mysocket"
      27  #define MAXMSG	512
      28  #define MESSAGE	"Yow!!! Are we having fun yet?!?"
      29  
      30  int
      31  main (void)
      32  {
      33    extern int make_named_socket (const char *name);
      34    int sock;
      35    char message[MAXMSG];
      36    struct sockaddr_un name;
      37    size_t size;
      38    int nbytes;
      39  
      40    /* Make the socket. */
      41    sock = make_named_socket (CLIENT);
      42  
      43    /* Initialize the server socket address. */
      44    name.sun_family = AF_LOCAL;
      45    strcpy (name.sun_path, SERVER);
      46    size = strlen (name.sun_path) + sizeof (name.sun_family);
      47  
      48    /* Send the datagram. */
      49    nbytes = sendto (sock, MESSAGE, strlen (MESSAGE) + 1, 0,
      50  		   (struct sockaddr *) & name, size);
      51    if (nbytes < 0)
      52      {
      53        perror ("sendto (client)");
      54        exit (EXIT_FAILURE);
      55      }
      56  
      57    /* Wait for a reply. */
      58    nbytes = recvfrom (sock, message, MAXMSG, 0, NULL, 0);
      59    if (nbytes < 0)
      60      {
      61        perror ("recfrom (client)");
      62        exit (EXIT_FAILURE);
      63      }
      64  
      65    /* Print a diagnostic message. */
      66    fprintf (stderr, "Client: got message: %s\n", message);
      67  
      68    /* Clean up. */
      69    remove (CLIENT);
      70    close (sock);
      71  }