#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <stdio.h>

#define DATA "The sea is calm tonight, the tide is full . . ."

/*
 * Here I send a datagram to a receiver whose name I get from the command
 * line arguments. The form of the command line is udgramsend pathname
 */

main(argc, argv)
     int argc;
     char *argv[];
{
     int sock;
     struct sockaddr_un name;

     /* Create socket on which to send. */
     sock = socket(AF_UNIX, SOCK_DGRAM, 0);
     if (sock < 0) {
          perror("opening datagram socket");
          exit(1);
     }

     /* Construct name of socket to send to. */
     name.sun_family = AF_UNIX;
     strcpy(name.sun_path, argv[1]);

     /* Send message. */
     if (sendto(sock, DATA, sizeof(DATA), 0,
          &name, sizeof(struct sockaddr_un)) < 0) {
          perror("sending datagram message");
     }
     close(sock);
}