get_names.c revision 1.7 
1/*	$OpenBSD: get_names.c,v 1.7 2000/12/31 00:24:51 hugh 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 1.7 2000/12/31 00:24:51 hugh 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 > 1 && !strcmp(argv[1], "-H")) {
67		argv[1] = argv[0];
68		++argv;
69		--argc;
70		high_print = 1;
71	}
72
73	if ((argc < 2 ) || ('@' == argv[1][0])) {
74		fprintf(stderr, "usage: talk user [ttyname]\n"
75				"       talk user@hostname [ttyname]\n");
76		exit(-1);
77	}
78	if (!isatty(0))
79		errx(1, "standard input must be a tty, not a pipe or a file");
80
81	if ((my_name = getlogin()) == NULL) {
82		struct passwd *pw;
83
84		if ((pw = getpwuid(getuid())) == NULL)
85			errx(1, "you don't exist in the passwd file.");
86		my_name = pw->pw_name;
87	}
88	gethostname(hostname, sizeof (hostname));
89	my_machine_name = hostname;
90	/* check for, and strip out, the machine name of the target */
91	names = strdup(argv[1]);
92	for (cp = names; *cp && !strchr("@:!.", *cp); cp++)
93		;
94	if (*cp == '\0') {
95		/* this is a local to local talk */
96		his_name = names;
97		his_machine_name = my_machine_name;
98	} else {
99		if (*cp++ == '@') {
100			/* user@host */
101			his_name = names;
102			his_machine_name = cp;
103		} else {
104			/* host.user or host!user or host:user */
105			his_name = cp;
106			his_machine_name = names;
107		}
108		*--cp = '\0';
109	}
110	if (argc > 2)
111		his_tty = argv[2];	/* tty name is arg 2 */
112	else
113		his_tty = "";
114	get_addrs(my_machine_name, his_machine_name);
115	/*
116	 * Initialize the message template.
117	 */
118	msg.vers = TALK_VERSION;
119	msg.addr.sa_family = htons(AF_INET);
120	msg.ctl_addr.sa_family = htons(AF_INET);
121	msg.id_num = htonl(0);
122	strncpy(msg.l_name, my_name, NAME_SIZE);
123	msg.l_name[NAME_SIZE - 1] = '\0';
124	strncpy(msg.r_name, his_name, NAME_SIZE);
125	msg.r_name[NAME_SIZE - 1] = '\0';
126	strncpy(msg.r_tty, his_tty, TTY_SIZE);
127	msg.r_tty[TTY_SIZE - 1] = '\0';
128}
129