1 /* Example of Reading Datagrams
2    Copyright (C) 1991-2022 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
main(void)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 }
72