1 .\" Copyright (c) 1986 Regents of the University of California.
2 .\" All rights reserved.  The Berkeley software License Agreement
3 .\" specifies the terms and conditions for redistribution.
4 .\"
5 .\"	@(#)strchkread.c	6.1 (Berkeley) 05/04/86
6 .\"
7 #include <sys/types.h>
8 #include <sys/socket.h>
9 #include <netinet/in.h>
10 #include <netdb.h>
11 #include <stdio.h>
12 #define TRUE 1
13 
14 /*
15  * This program uses select() to check that someone is trying to connect
16  * before calling accept().
17  */
18 
19 main()
20 {
21 	int             sock, length;
22 	struct sockaddr_in server;
23 	int             msgsock;
24 	char            buf[1024];
25 	int             rval;
26 	int             i;
27 	int             ready;
28 	struct timeval  to;
29 
30 	/* Create socket */
31 	sock = socket(AF_INET, SOCK_STREAM, 0);
32 	if (sock < 0) {
33 		perror("opening stream socket");
34 		exit(0);
35 	}
36 	/* Name socket using wildcards */
37 	server.sin_family = AF_INET;
38 	server.sin_addr.s_addr = INADDR_ANY;
39 	server.sin_port = 0;
40 	if (bind(sock, &server, sizeof(server))) {
41 		perror("binding stream socket");
42 	}
43 	/* Find out assigned port number and print it out */
44 	length = sizeof(server);
45 	if (getsockname(sock, &server, &length)) {
46 		perror("getting socket name");
47 		exit(0);
48 	}
49 	printf("Socket has port #%d\en", ntohs(server.sin_port));
50 
51 	/* Start accepting connections */
52 	listen(sock, 5);
53 	do {
54 		ready = 1 << sock;
55 		to.tv_sec = 5;
56 		select(20, &ready, 0, 0, &to);
57 		if (ready) {
58 			msgsock = accept(sock, 0, 0);
59 			do {
60 				for (i = 0; i < 1024; i++)
61 					buf[i] = '\e0';
62 				if ((rval = read(msgsock, buf, 1024)) < 0)
63 					perror("reading stream message");
64 				i = 0;
65 				if (rval == 0)
66 					printf("Ending connection\en");
67 				else
68 					printf("-->%s\en", buf);
69 			} while (rval != 0);
70 			close(msgsock);
71 		} else
72 			printf("Do something else\en");
73 	} while (TRUE);
74 }
75