books/apitue/sample-code/08/streamwrite.c

101 lines
3.4 KiB
C

/* This file is part of the sample code and exercises
* used by the class "Advanced Programming in the UNIX
* Environment" taught by Jan Schaumann
* <jschauma@netmeister.org> at Stevens Institute of
* Technology.
*
* https://stevens.netmeister.org/631/
*/
/* $NetBSD: streamwrite.c,v 1.3 2003/08/07 10:30:50 agc Exp $
*
* Copyright (c) 1986, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)streamwrite.c 8.1 (Berkeley) 6/8/93
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/* http://poetry.eserver.org/light-brigade.html */
#define DATA "Half a league, half a league . . ."
/*
* This program creates a socket and initiates a connection with the socket
* given in the command line. One message is sent over the connection and
* then the socket is closed, ending the connection. The form of the command
* line is streamwrite hostname portnumber
*/
int main(int argc, char **argv)
{
int sock, port;
struct sockaddr_in6 server;
struct hostent *hp;
memset(&server, 0, sizeof(server));
if (argc != 3) {
(void)printf("Usage: %s hostname port\n", argv[0]);
exit(EXIT_FAILURE);
}
port = atoi(argv[2]);
if ((port < 1) || (port > 65536)) {
(void)fprintf(stderr, "Invalid port: %s\n", argv[2]);
exit(EXIT_FAILURE);
}
if ((sock = socket(PF_INET6, SOCK_STREAM, 0)) < 0) {
perror("opening stream socket");
exit(EXIT_FAILURE);
}
server.sin6_family = PF_INET6;
if ((hp = gethostbyname2(argv[1], PF_INET6)) == NULL) {
(void)fprintf(stderr, "%s: unknown host\n", argv[1]);
exit(EXIT_FAILURE);
}
bcopy(hp->h_addr, &server.sin6_addr, hp->h_length);
server.sin6_port = htons(port);
if (connect(sock, (struct sockaddr *)&server, sizeof(server)) < 0) {
perror("connecting stream socket");
exit(EXIT_FAILURE);
}
if (write(sock, DATA, sizeof(DATA)) < 0)
perror("writing on stream socket");
(void)close(sock);
return EXIT_FAILURE;
}