/share/doc/psd/20.ipctut/ustreamread.c

 1.\" Copyright (c) 1986, 1993
 2.\"	The Regents of the University of California.  All rights reserved.
 3.\"
 4.\" Redistribution and use in source and binary forms, with or without
 5.\" modification, are permitted provided that the following conditions
 6.\" are met:
 7.\" 1. Redistributions of source code must retain the above copyright
 8.\"    notice, this list of conditions and the following disclaimer.
 9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\" 3. All advertising materials mentioning features or use of this software
13.\"    must display the following acknowledgement:
14.\"	This product includes software developed by the University of
15.\"	California, Berkeley and its contributors.
16.\" 4. Neither the name of the University nor the names of its contributors
17.\"    may be used to endorse or promote products derived from this software
18.\"    without specific prior written permission.
19.\"
20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30.\" SUCH DAMAGE.
31.\"
32.\"	@(#)ustreamread.c	8.1 (Berkeley) 6/8/93
33.\"
34#include <sys/types.h>
35#include <sys/socket.h>
36#include <sys/un.h>
37#include <stdio.h>
38
39#define NAME "socket"
40
41/*
42 * This program creates a socket in the UNIX domain and binds a name to it.
43 * After printing the socket's name it begins a loop. Each time through the
44 * loop it accepts a connection and prints out messages from it.  When the
45 * connection breaks, or a termination message comes through, the program
46 * accepts a new connection.
47 */
48main()
49{
50	int sock, msgsock, rval;
51	struct sockaddr_un server;
52	char buf[1024];
53
54	/* Create socket */
55	sock = socket(AF_UNIX, SOCK_STREAM, 0);
56	if (sock < 0) {
57		perror("opening stream socket");
58		exit(1);
59	}
60	/* Name socket using file system name */
61	server.sun_family = AF_UNIX;
62	strcpy(server.sun_path, NAME);
63	if (bind(sock, &server, sizeof(struct sockaddr_un))) {
64		perror("binding stream socket");
65		exit(1);
66	}
67	printf("Socket has name %s\en", server.sun_path);
68	/* Start accepting connections */
69	listen(sock, 5);
70	for (;;) {
71		msgsock = accept(sock, 0, 0);
72		if (msgsock == -1)
73			perror("accept");
74		else do {
75			bzero(buf, sizeof(buf));
76			if ((rval = read(msgsock, buf, 1024)) < 0)
77				perror("reading stream message");
78			else if (rval == 0)
79				printf("Ending connection\en");
80			else
81				printf("-->%s\en", buf);
82		} while (rval > 0);
83		close(msgsock);
84	}
85	/*
86	 * The following statements are not executed, because they follow an
87	 * infinite loop.  However, most ordinary programs will not run
88	 * forever.  In the UNIX domain it is necessary to tell the file
89	 * system that one is through using NAME.  In most programs one uses
90	 * the call unlink() as below. Since the user will have to kill this
91	 * program, it will be necessary to remove the name by a command from
92	 * the shell.
93	 */
94	close(sock);
95	unlink(NAME);
96}