xref: /freebsd/share/doc/psd/20.ipctut/ustreamread.c (revision bc96366c864c07ef352edb92017357917c75b36c)
1 .\" Copyright (c) 1986, 1993
2 .\"	The Regents of the University of California.  All rights reserved.
3 .\"
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9 .\" 2. Redistributions in binary form must reproduce the above copyright
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11 .\"    documentation and/or other materials provided with the distribution.
12 .\" 3. Neither the name of the University nor the names of its contributors
13 .\"    may be used to endorse or promote products derived from this software
14 .\"    without specific prior written permission.
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16 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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18 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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28 .\"	@(#)ustreamread.c	8.1 (Berkeley) 6/8/93
29 .\"
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <sys/un.h>
33 #include <stdio.h>
34 
35 #define NAME "socket"
36 
37 /*
38  * This program creates a socket in the UNIX domain and binds a name to it.
39  * After printing the socket's name it begins a loop. Each time through the
40  * loop it accepts a connection and prints out messages from it.  When the
41  * connection breaks, or a termination message comes through, the program
42  * accepts a new connection.
43  */
44 main()
45 {
46 	int sock, msgsock, rval;
47 	struct sockaddr_un server;
48 	char buf[1024];
49 
50 	/* Create socket */
51 	sock = socket(AF_UNIX, SOCK_STREAM, 0);
52 	if (sock < 0) {
53 		perror("opening stream socket");
54 		exit(1);
55 	}
56 	/* Name socket using file system name */
57 	server.sun_family = AF_UNIX;
58 	strcpy(server.sun_path, NAME);
59 	if (bind(sock, &server, sizeof(struct sockaddr_un))) {
60 		perror("binding stream socket");
61 		exit(1);
62 	}
63 	printf("Socket has name %s\en", server.sun_path);
64 	/* Start accepting connections */
65 	listen(sock, 5);
66 	for (;;) {
67 		msgsock = accept(sock, 0, 0);
68 		if (msgsock == -1)
69 			perror("accept");
70 		else do {
71 			bzero(buf, sizeof(buf));
72 			if ((rval = read(msgsock, buf, 1024)) < 0)
73 				perror("reading stream message");
74 			else if (rval == 0)
75 				printf("Ending connection\en");
76 			else
77 				printf("-->%s\en", buf);
78 		} while (rval > 0);
79 		close(msgsock);
80 	}
81 	/*
82 	 * The following statements are not executed, because they follow an
83 	 * infinite loop.  However, most ordinary programs will not run
84 	 * forever.  In the UNIX domain it is necessary to tell the file
85 	 * system that one is through using NAME.  In most programs one uses
86 	 * the call unlink() as below. Since the user will have to kill this
87 	 * program, it will be necessary to remove the name by a command from
88 	 * the shell.
89 	 */
90 	close(sock);
91 	unlink(NAME);
92 }
93