/* receiver for unix domain datagram demo */

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

help_msg()
{
	printf("format: ustr\n");
}

main(argc, argv)
int argc;
char *argv[];
{
	int sock; 
	int msgsock;
	struct sockaddr_un to;
	struct sockaddr_un addr;
	int n, i;
	char toBuf[2048];
	char fromBuf[2048];
	int length;
	int flag = 1;

	/* create socket */
	sock = socket(AF_UNIX, SOCK_STREAM, 0);
	if (sock < 0) {
		perror("opening stream socket");
		exit(1);
	}
	addr.sun_family = AF_UNIX;
	sprintf(addr.sun_path, "/tmp/cs522.%s.server", getlogin());
	unlink(addr.sun_path); /* if previous incarnation of server still exists */
	if (bind(sock, &addr, sizeof(struct sockaddr_un))) {
		perror("binding name to datagram socket");
		exit(1);
	}
	/* ls -F /tmp  you will find a file with the same name there */
	printf("unix domain stream server uses sun_path=%s\n", addr.sun_path);

	/* receive message */
	listen(sock, 2);
	do {
		msgsock = accept(sock, 0, 0);
		printf("msgsock=%d\n", msgsock);
		if (msgsock == -1) {
			perror("accept"); exit(2);
		} else do {
			n = read(msgsock, fromBuf, sizeof(fromBuf));
			if (n < 0) {
				perror("receiving datagram message");
				exit(3);
				}
			if (n == 0) {
				printf("The Client Ending connection\n");
				break;
				}
			fromBuf[n] = 0; /* null terminate */
			printf("The no. of bytes received=%d\n", n);
			printf("received msg=");
			for (i=0; i<n; i++) {
				if ((i+1)%80 == 0) printf("\n");
				else printf("%c", fromBuf[i]);
			}
	
			sprintf(toBuf, "received message: %s\n", fromBuf);
			if (write(msgsock, toBuf, strlen(toBuf)) < 0) { 
				perror("sending datagram message");
				exit(4);
				}
			} while (n != 0);
		close(msgsock);
	} while (1);
}