xref: /freebsd/share/doc/psd/20.ipctut/ustreamread.c (revision 97759ccc715c4b365432c16d763c50eecfcb1100)

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

#define NAME "socket"

/*
 * This program creates a socket in the UNIX domain and binds a name to it.
 * After printing the socket's name it begins a loop. Each time through the
 * loop it accepts a connection and prints out messages from it.  When the
 * connection breaks, or a termination message comes through, the program
 * accepts a new connection.
 */
main()
{
	int sock, msgsock, rval;
	struct sockaddr_un server;
	char buf[1024];

	/* Create socket */
	sock = socket(AF_UNIX, SOCK_STREAM, 0);
	if (sock < 0) {
		perror("opening stream socket");
		exit(1);
	}
	/* Name socket using file system name */
	server.sun_family = AF_UNIX;
	strcpy(server.sun_path, NAME);
	if (bind(sock, &server, sizeof(struct sockaddr_un))) {
		perror("binding stream socket");
		exit(1);
	}
	printf("Socket has name %s\en", server.sun_path);
	/* Start accepting connections */
	listen(sock, 5);
	for (;;) {
		msgsock = accept(sock, 0, 0);
		if (msgsock == -1)
			perror("accept");
		else do {
			bzero(buf, sizeof(buf));
			if ((rval = read(msgsock, buf, 1024)) < 0)
				perror("reading stream message");
			else if (rval == 0)
				printf("Ending connection\en");
			else
				printf("-->%s\en", buf);
		} while (rval > 0);
		close(msgsock);
	}
	/*
	 * The following statements are not executed, because they follow an
	 * infinite loop.  However, most ordinary programs will not run
	 * forever.  In the UNIX domain it is necessary to tell the file
	 * system that one is through using NAME.  In most programs one uses
	 * the call unlink() as below. Since the user will have to kill this
	 * program, it will be necessary to remove the name by a command from
	 * the shell.
	 */
	close(sock);
	unlink(NAME);
}