/* sender for unix domain datagram demo */

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

help_msg()
{
	printf("format: idgs -[d] unix_sock_path_name\n");
	printf("          option: d set debug mode\n");
}

main(argc, argv)
int argc;
char *argv[];
{
	int sock; 
	struct sockaddr_un to;
	struct sockaddr_un addr;
	int n;
	char toBuf[1024];
	char fromBuf[1024];
	extern char *optarg;
	extern int   optind;
	int option_exist = 0;
	int c;
	int debug = 0;
	int length;
	int flag;

	/* process command line args */
	while ((c=getopt(argc,argv,"dn:")) != EOF)
	{
		option_exist = 1;
		switch(c)
		{
		case 'd':
			debug = 1;
			if (debug)
				printf("turn on debug mode.\n");
			break;

		case '?':
			help_msg();
			exit (1);
		default:
			fprintf (stderr, "unrecognized arg >%s<\n", optarg);
			help_msg();
			exit (1);
		}
	}

	to.sun_family = AF_UNIX;
	strcpy(to.sun_path, argv[optind++]);
	printf("The receiver's sun_path is %s\n", to.sun_path);

	/* create socket from which to read */
	sock = socket(AF_UNIX, SOCK_DGRAM, 0);
	if (sock < 0) {
		perror("opening datagram socket");
		exit(1);
	}
	/* create name structure with wildcard using INADDR_ANY */
	addr.sun_family = AF_UNIX;
	sprintf(addr.sun_path, "/tmp/cs522.%s.client", getlogin());
	unlink(addr.sun_path);
	if (bind(sock, &addr, sizeof(struct sockaddr_un))) {
		perror("binding name to datagram socket");
		exit(1);
	}
	printf("unix domain datagram client sun_path=%s\n", addr.sun_path);

	/*send message */
	printf("sending message: This is packet one!\n");
	sprintf(toBuf, "This is packet one!\n");
	if (sendto(sock, toBuf, strlen(toBuf), 0, &to, sizeof(to)) < 0) 
		perror("sending datagram message");
	n = recv(sock, fromBuf, 1024, 0);
	if (n < 0) perror("receiving datagram message");
	fromBuf[n] = 0; /* null terminate */
	printf("number of bytes received=%d\n", n);
	printf("received ack msg=%s\n", fromBuf);
	unlink(addr.sun_path);
	close(sock);
}