81 lines
3.0 KiB
C
81 lines
3.0 KiB
C
.\" Copyright (c) 1986, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)dgramsend.c 8.1 (Berkeley) 6/8/93
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.\"
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <netdb.h>
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#include <stdio.h>
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#define DATA "The sea is calm tonight, the tide is full . . ."
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/*
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* Here I send a datagram to a receiver whose name I get from the command
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* line arguments. The form of the command line is dgramsend hostname
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* portnumber
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*/
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main(argc, argv)
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int argc;
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char *argv[];
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{
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int sock;
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struct sockaddr_in name;
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struct hostent *hp, *gethostbyname();
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/* Create socket on which to send. */
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sock = socket(AF_INET, SOCK_DGRAM, 0);
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if (sock < 0) {
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perror("opening datagram socket");
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exit(1);
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}
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/*
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* Construct name, with no wildcards, of the socket to send to.
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* Getnostbyname() returns a structure including the network address
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* of the specified host. The port number is taken from the command
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* line.
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*/
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hp = gethostbyname(argv[1]);
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if (hp == 0) {
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fprintf(stderr, "%s: unknown host\n", argv[1]);
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exit(2);
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}
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bcopy(hp->h_addr, &name.sin_addr, hp->h_length);
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name.sin_family = AF_INET;
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name.sin_port = htons(atoi(argv[2]));
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/* Send message. */
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if (sendto(sock, DATA, sizeof(DATA), 0, &name, sizeof(name)) < 0)
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perror("sending datagram message");
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close(sock);
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}
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