1*075022b3Sagc .\" $NetBSD: dgramsend.c,v 1.3 2003/08/07 10:30:50 agc Exp $ 26d400d56Sperry .\" 3d9158b13Scgd .\" Copyright (c) 1986, 1993 4d9158b13Scgd .\" The Regents of the University of California. All rights reserved. 5d9158b13Scgd .\" 6d9158b13Scgd .\" Redistribution and use in source and binary forms, with or without 7d9158b13Scgd .\" modification, are permitted provided that the following conditions 8d9158b13Scgd .\" are met: 9d9158b13Scgd .\" 1. Redistributions of source code must retain the above copyright 10d9158b13Scgd .\" notice, this list of conditions and the following disclaimer. 11d9158b13Scgd .\" 2. Redistributions in binary form must reproduce the above copyright 12d9158b13Scgd .\" notice, this list of conditions and the following disclaimer in the 13d9158b13Scgd .\" documentation and/or other materials provided with the distribution. 14*075022b3Sagc .\" 3. Neither the name of the University nor the names of its contributors 15d9158b13Scgd .\" may be used to endorse or promote products derived from this software 16d9158b13Scgd .\" without specific prior written permission. 17d9158b13Scgd .\" 18d9158b13Scgd .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19d9158b13Scgd .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20d9158b13Scgd .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21d9158b13Scgd .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22d9158b13Scgd .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23d9158b13Scgd .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24d9158b13Scgd .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25d9158b13Scgd .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26d9158b13Scgd .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27d9158b13Scgd .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28d9158b13Scgd .\" SUCH DAMAGE. 29d9158b13Scgd .\" 30d9158b13Scgd .\" @(#)dgramsend.c 8.1 (Berkeley) 6/8/93 31d9158b13Scgd .\" 32d9158b13Scgd #include <sys/types.h> 33d9158b13Scgd #include <sys/socket.h> 34d9158b13Scgd #include <netinet/in.h> 35d9158b13Scgd #include <netdb.h> 36d9158b13Scgd #include <stdio.h> 37d9158b13Scgd 38d9158b13Scgd #define DATA "The sea is calm tonight, the tide is full . . ." 39d9158b13Scgd 40d9158b13Scgd /* 41d9158b13Scgd * Here I send a datagram to a receiver whose name I get from the command 42d9158b13Scgd * line arguments. The form of the command line is dgramsend hostname 43d9158b13Scgd * portnumber 44d9158b13Scgd */ 45d9158b13Scgd 46d9158b13Scgd main(argc, argv) 47d9158b13Scgd int argc; 48d9158b13Scgd char *argv[]; 49d9158b13Scgd { 50d9158b13Scgd int sock; 51d9158b13Scgd struct sockaddr_in name; 52d9158b13Scgd struct hostent *hp, *gethostbyname(); 53d9158b13Scgd 54d9158b13Scgd /* Create socket on which to send. */ 55d9158b13Scgd sock = socket(AF_INET, SOCK_DGRAM, 0); 56d9158b13Scgd if (sock < 0) { 57d9158b13Scgd perror("opening datagram socket"); 58d9158b13Scgd exit(1); 59d9158b13Scgd } 60d9158b13Scgd /* 61d9158b13Scgd * Construct name, with no wildcards, of the socket to send to. 62d9158b13Scgd * Getnostbyname() returns a structure including the network address 63d9158b13Scgd * of the specified host. The port number is taken from the command 64d9158b13Scgd * line. 65d9158b13Scgd */ 66d9158b13Scgd hp = gethostbyname(argv[1]); 67d9158b13Scgd if (hp == 0) { 68d9158b13Scgd fprintf(stderr, "%s: unknown host\n", argv[1]); 69d9158b13Scgd exit(2); 70d9158b13Scgd } 71d9158b13Scgd bcopy(hp->h_addr, &name.sin_addr, hp->h_length); 72d9158b13Scgd name.sin_family = AF_INET; 73d9158b13Scgd name.sin_port = htons(atoi(argv[2])); 74d9158b13Scgd /* Send message. */ 75d9158b13Scgd if (sendto(sock, DATA, sizeof(DATA), 0, &name, sizeof(name)) < 0) 76d9158b13Scgd perror("sending datagram message"); 77d9158b13Scgd close(sock); 78d9158b13Scgd } 79