/* * Copyright (c) 1986 The Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that the above copyright notice and this paragraph are * duplicated in all such forms and that any documentation, * advertising materials, and other materials related to such * distribution and use acknowledge that the software was developed * by the University of California, Berkeley. The name of the * University may not be used to endorse or promote products derived * from this software without specific prior written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #ifndef lint char copyright[] = "@(#) Copyright (c) 1986 The Regents of the University of California.\n\ All rights reserved.\n"; #endif /* not lint */ #ifndef lint static char sccsid[] = "@(#)dgramsend.c 6.3 (Berkeley) 03/07/89"; #endif /* not lint */ #include #include #include #include #include #define DATA "The sea is calm tonight, the tide is full . . ." /* * Here I send a datagram to a receiver whose name I get from the command * line arguments. The form of the command line is dgramsend hostname * portnumber */ main(argc, argv) int argc; char *argv[]; { int sock; struct sockaddr_in name; struct hostent *hp, *gethostbyname(); /* Create socket on which to send. */ sock = socket(AF_INET, SOCK_DGRAM, 0); if (sock < 0) { perror("opening datagram socket"); exit(1); } /* * Construct name, with no wildcards, of the socket to send to. * Getnostbyname() returns a structure including the network address * of the specified host. The port number is taken from the command * line. */ hp = gethostbyname(argv[1]); if (hp == 0) { fprintf(stderr, "%s: unknown host\n", argv[1]); exit(2); } bcopy(hp->h_addr, &name.sin_addr, hp->h_length); name.sin_family = AF_INET; name.sin_port = htons(atoi(argv[2])); /* Send message. */ if (sendto(sock, DATA, sizeof(DATA), 0, &name, sizeof(name)) < 0) perror("sending datagram message"); close(sock); }