1 .\" $NetBSD: dgramsend.c,v 1.2 1998/01/09 06:54:59 perry Exp $ 2 .\" 3 .\" Copyright (c) 1986, 1993 4 .\" The Regents of the University of California. All rights reserved. 5 .\" 6 .\" Redistribution and use in source and binary forms, with or without 7 .\" modification, are permitted provided that the following conditions 8 .\" are met: 9 .\" 1. Redistributions of source code must retain the above copyright 10 .\" notice, this list of conditions and the following disclaimer. 11 .\" 2. Redistributions in binary form must reproduce the above copyright 12 .\" notice, this list of conditions and the following disclaimer in the 13 .\" documentation and/or other materials provided with the distribution. 14 .\" 3. All advertising materials mentioning features or use of this software 15 .\" must display the following acknowledgement: 16 .\" This product includes software developed by the University of 17 .\" California, Berkeley and its contributors. 18 .\" 4. Neither the name of the University nor the names of its contributors 19 .\" may be used to endorse or promote products derived from this software 20 .\" without specific prior written permission. 21 .\" 22 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 .\" SUCH DAMAGE. 33 .\" 34 .\" @(#)dgramsend.c 8.1 (Berkeley) 6/8/93 35 .\" 36 #include <sys/types.h> 37 #include <sys/socket.h> 38 #include <netinet/in.h> 39 #include <netdb.h> 40 #include <stdio.h> 41 42 #define DATA "The sea is calm tonight, the tide is full . . ." 43 44 /* 45 * Here I send a datagram to a receiver whose name I get from the command 46 * line arguments. The form of the command line is dgramsend hostname 47 * portnumber 48 */ 49 50 main(argc, argv) 51 int argc; 52 char *argv[]; 53 { 54 int sock; 55 struct sockaddr_in name; 56 struct hostent *hp, *gethostbyname(); 57 58 /* Create socket on which to send. */ 59 sock = socket(AF_INET, SOCK_DGRAM, 0); 60 if (sock < 0) { 61 perror("opening datagram socket"); 62 exit(1); 63 } 64 /* 65 * Construct name, with no wildcards, of the socket to send to. 66 * Getnostbyname() returns a structure including the network address 67 * of the specified host. The port number is taken from the command 68 * line. 69 */ 70 hp = gethostbyname(argv[1]); 71 if (hp == 0) { 72 fprintf(stderr, "%s: unknown host\n", argv[1]); 73 exit(2); 74 } 75 bcopy(hp->h_addr, &name.sin_addr, hp->h_length); 76 name.sin_family = AF_INET; 77 name.sin_port = htons(atoi(argv[2])); 78 /* Send message. */ 79 if (sendto(sock, DATA, sizeof(DATA), 0, &name, sizeof(name)) < 0) 80 perror("sending datagram message"); 81 close(sock); 82 } 83