get_names.c revision 1.5 
1/*	$OpenBSD: get_names.c,v 1.5 1998/04/28 22:13:25 pjanzen Exp $	*/
2/*	$NetBSD: get_names.c,v 1.4 1994/12/09 02:14:16 jtc Exp $	*/
3
4/*
5 * Copyright (c) 1983, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38#if 0
39static char sccsid[] = "@(#)get_names.c	8.1 (Berkeley) 6/6/93";
40#endif
41static char rcsid[] = "$OpenBSD: get_names.c,v 1.5 1998/04/28 22:13:25 pjanzen Exp $";
42#endif /* not lint */
43
44#include "talk.h"
45#include <sys/param.h>
46#include <pwd.h>
47#include <unistd.h>
48
49extern	CTL_MSG msg;
50
51/*
52 * Determine the local and remote user, tty, and machines
53 */
54void
55get_names(argc, argv)
56	int argc;
57	char *argv[];
58{
59	char hostname[MAXHOSTNAMELEN];
60	char *his_name, *my_name;
61	char *my_machine_name, *his_machine_name;
62	char *his_tty;
63	register char *cp;
64	char *names;
65
66	if ((argc < 2 ) || ('@' == argv[1][0])) {
67		printf("Usage: talk user [ttyname]\n");
68		printf("       talk user@hostname [ttyname]\n");
69		exit(-1);
70	}
71	if (!isatty(0)) {
72		printf("Standard input must be a tty, not a pipe or a file\n");
73		exit(-1);
74	}
75
76	if ((my_name = getlogin()) == NULL) {
77		struct passwd *pw;
78
79		if ((pw = getpwuid(getuid())) == NULL) {
80			printf("You don't exist. Go away.\n");
81			exit(-1);
82		}
83		my_name = pw->pw_name;
84	}
85	gethostname(hostname, sizeof (hostname));
86	my_machine_name = hostname;
87	/* check for, and strip out, the machine name of the target */
88	names = strdup(argv[1]);
89	for (cp = names; *cp && !strchr("@:!.", *cp); cp++)
90		;
91	if (*cp == '\0') {
92		/* this is a local to local talk */
93		his_name = names;
94		his_machine_name = my_machine_name;
95	} else {
96		if (*cp++ == '@') {
97			/* user@host */
98			his_name = names;
99			his_machine_name = cp;
100		} else {
101			/* host.user or host!user or host:user */
102			his_name = cp;
103			his_machine_name = names;
104		}
105		*--cp = '\0';
106	}
107	if (argc > 2)
108		his_tty = argv[2];	/* tty name is arg 2 */
109	else
110		his_tty = "";
111	get_addrs(my_machine_name, his_machine_name);
112	/*
113	 * Initialize the message template.
114	 */
115	msg.vers = TALK_VERSION;
116	msg.addr.sa_family = htons(AF_INET);
117	msg.ctl_addr.sa_family = htons(AF_INET);
118	msg.id_num = htonl(0);
119	strncpy(msg.l_name, my_name, NAME_SIZE);
120	msg.l_name[NAME_SIZE - 1] = '\0';
121	strncpy(msg.r_name, his_name, NAME_SIZE);
122	msg.r_name[NAME_SIZE - 1] = '\0';
123	strncpy(msg.r_tty, his_tty, TTY_SIZE);
124	msg.r_tty[TTY_SIZE - 1] = '\0';
125}
126