get_names.c revision 78733 
1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35#if 0
36static char sccsid[] = "@(#)get_names.c	8.1 (Berkeley) 6/6/93";
37#endif
38static const char rcsid[] =
39  "$FreeBSD: head/usr.bin/talk/get_names.c 78733 2001-06-24 23:22:14Z dd $";
40#endif /* not lint */
41
42#include <err.h>
43#include <pwd.h>
44#include <stdlib.h>
45#include <string.h>
46#include <sys/param.h>
47#include "talk.h"
48
49extern	CTL_MSG msg;
50
51static void
52usage(void)
53{
54	fprintf(stderr, "usage: talk person [ttyname]\n");
55	exit(1);
56}
57
58/*
59 * Determine the local and remote user, tty, and machines
60 */
61void
62get_names(argc, argv)
63	int argc;
64	char *argv[];
65{
66	char hostname[MAXHOSTNAMELEN];
67	char *his_name, *my_name;
68	char *my_machine_name, *his_machine_name;
69	char *my_tty, *his_tty;
70	register char *cp;
71
72	if (argc < 2 )
73		usage();
74	if (!isatty(0))
75		errx(1, "standard input must be a tty, not a pipe or a file");
76	if ((my_name = getlogin()) == NULL) {
77		struct passwd *pw;
78
79		if ((pw = getpwuid(getuid())) == NULL)
80			errx(1, "you don't exist. Go away");
81		my_name = pw->pw_name;
82	}
83	gethostname(hostname, sizeof (hostname));
84	my_machine_name = hostname;
85	/* check for, and strip out, the machine name of the target */
86	for (cp = argv[1]; *cp && !index("@:!", *cp); cp++)
87		;
88	if (*cp == '\0') {
89		/* this is a local to local talk */
90		his_name = argv[1];
91		his_machine_name = my_machine_name;
92	} else {
93		if (*cp++ == '@') {
94			/* user@host */
95			his_name = argv[1];
96			his_machine_name = cp;
97		} else {
98			/* host!user or host:user */
99			his_name = cp;
100			his_machine_name = argv[1];
101		}
102		*--cp = '\0';
103	}
104	if (argc > 2)
105		his_tty = argv[2];	/* tty name is arg 2 */
106	else
107		his_tty = "";
108	get_addrs(my_machine_name, his_machine_name);
109	/*
110	 * Initialize the message template.
111	 */
112	msg.vers = TALK_VERSION;
113	msg.addr.sa_family = htons(AF_INET);
114	msg.ctl_addr.sa_family = htons(AF_INET);
115	msg.id_num = htonl(0);
116	strncpy(msg.l_name, my_name, NAME_SIZE);
117	msg.l_name[NAME_SIZE - 1] = '\0';
118	strncpy(msg.r_name, his_name, NAME_SIZE);
119	msg.r_name[NAME_SIZE - 1] = '\0';
120	strncpy(msg.r_tty, his_tty, TTY_SIZE);
121	msg.r_tty[TTY_SIZE - 1] = '\0';
122}
123