/* This file is part of the sample code and exercises
 * used by the class "Advanced Programming in the UNIX
 * Environment" taught by Jan Schaumann
 * <jschauma@netmeister.org> at Stevens Institute of
 * Technology.
 *
 * https://stevens.netmeister.org/631/
 */

/*	$NetBSD: udgramread.c,v 1.3 2003/08/07 10:30:50 agc Exp $
 *
 * Copyright (c) 1986, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)udgramread.c	8.1 (Berkeley) 6/8/93
 */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>

/*
 * In the included file <sys/un.h> a sockaddr_un is defined as follows
 * struct sockaddr_un {
 *	short	sun_family;
 *	char	sun_path[108];
 * };
 */

#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define NAME "socket"

/*
 * This program creates a UNIX domain datagram socket, binds a name to it,
 * then reads from the socket.
 */
int main()
{
	int sock;
	struct sockaddr_un name;
	char buf[BUFSIZ];

	if ((sock = socket(PF_LOCAL, SOCK_DGRAM, 0)) < 0) {
		perror("opening datagram socket");
		exit(EXIT_FAILURE);
	}

	name.sun_family = PF_LOCAL;
	(void)strncpy(name.sun_path, NAME, sizeof(name.sun_path));
	if (bind(sock, (struct sockaddr *)&name, sizeof(struct sockaddr_un))) {
		perror("binding name to datagram socket");
		exit(EXIT_FAILURE);
	}
	(void)printf("socket --> %s\n", NAME);

	while (1) {
		bzero(buf, BUFSIZ);
		if (read(sock, buf, BUFSIZ) < 0)
			perror("reading from socket");
		(void)printf("--> %s\n", buf);
	}
	(void)close(sock);

	/* A UNIX domain datagram socket is a 'file'.  If you don't unlink
	 * it, it will remain in the file system. */
	(void)unlink(NAME);
	return EXIT_SUCCESS;
}