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. 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. 15 .\" 16 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 .\" SUCH DAMAGE. 27 .\" 28 #include <sys/types.h> 29 #include <sys/socket.h> 30 #include <sys/un.h> 31 #include <stdio.h> 32 33 #define NAME "socket" 34 35 /* 36 * This program creates a socket in the UNIX domain and binds a name to it. 37 * After printing the socket's name it begins a loop. Each time through the 38 * loop it accepts a connection and prints out messages from it. When the 39 * connection breaks, or a termination message comes through, the program 40 * accepts a new connection. 41 */ 42 main() 43 { 44 int sock, msgsock, rval; 45 struct sockaddr_un server; 46 char buf[1024]; 47 48 /* Create socket */ 49 sock = socket(AF_UNIX, SOCK_STREAM, 0); 50 if (sock < 0) { 51 perror("opening stream socket"); 52 exit(1); 53 } 54 /* Name socket using file system name */ 55 server.sun_family = AF_UNIX; 56 strcpy(server.sun_path, NAME); 57 if (bind(sock, &server, sizeof(struct sockaddr_un))) { 58 perror("binding stream socket"); 59 exit(1); 60 } 61 printf("Socket has name %s\en", server.sun_path); 62 /* Start accepting connections */ 63 listen(sock, 5); 64 for (;;) { 65 msgsock = accept(sock, 0, 0); 66 if (msgsock == -1) 67 perror("accept"); 68 else do { 69 bzero(buf, sizeof(buf)); 70 if ((rval = read(msgsock, buf, 1024)) < 0) 71 perror("reading stream message"); 72 else if (rval == 0) 73 printf("Ending connection\en"); 74 else 75 printf("-->%s\en", buf); 76 } while (rval > 0); 77 close(msgsock); 78 } 79 /* 80 * The following statements are not executed, because they follow an 81 * infinite loop. However, most ordinary programs will not run 82 * forever. In the UNIX domain it is necessary to tell the file 83 * system that one is through using NAME. In most programs one uses 84 * the call unlink() as below. Since the user will have to kill this 85 * program, it will be necessary to remove the name by a command from 86 * the shell. 87 */ 88 close(sock); 89 unlink(NAME); 90 } 91