xref: /dragonfly/usr.bin/talk/get_names.c (revision 1de703da)
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  * @(#)get_names.c	8.1 (Berkeley) 6/6/93
34  * $FreeBSD: src/usr.bin/talk/get_names.c,v 1.6.2.1 2001/07/30 10:31:29 dd Exp $
35  * $DragonFly: src/usr.bin/talk/get_names.c,v 1.2 2003/06/17 04:29:32 dillon Exp $
36  */
37 
38 #include <err.h>
39 #include <pwd.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <sys/param.h>
43 #include "talk.h"
44 
45 extern	CTL_MSG msg;
46 
47 static void
48 usage(void)
49 {
50 	fprintf(stderr, "usage: talk person [ttyname]\n");
51 	exit(1);
52 }
53 
54 /*
55  * Determine the local and remote user, tty, and machines
56  */
57 void
58 get_names(argc, argv)
59 	int argc;
60 	char *argv[];
61 {
62 	char hostname[MAXHOSTNAMELEN];
63 	char *his_name, *my_name;
64 	char *my_machine_name, *his_machine_name;
65 	char *my_tty, *his_tty;
66 	register char *cp;
67 
68 	if (argc < 2 )
69 		usage();
70 	if (!isatty(0))
71 		errx(1, "standard input must be a tty, not a pipe or a file");
72 	if ((my_name = getlogin()) == NULL) {
73 		struct passwd *pw;
74 
75 		if ((pw = getpwuid(getuid())) == NULL)
76 			errx(1, "you don't exist. Go away");
77 		my_name = pw->pw_name;
78 	}
79 	gethostname(hostname, sizeof (hostname));
80 	my_machine_name = hostname;
81 	/* check for, and strip out, the machine name of the target */
82 	for (cp = argv[1]; *cp && !index("@:!", *cp); cp++)
83 		;
84 	if (*cp == '\0') {
85 		/* this is a local to local talk */
86 		his_name = argv[1];
87 		his_machine_name = my_machine_name;
88 	} else {
89 		if (*cp++ == '@') {
90 			/* user@host */
91 			his_name = argv[1];
92 			his_machine_name = cp;
93 		} else {
94 			/* host!user or host:user */
95 			his_name = cp;
96 			his_machine_name = argv[1];
97 		}
98 		*--cp = '\0';
99 	}
100 	if (argc > 2)
101 		his_tty = argv[2];	/* tty name is arg 2 */
102 	else
103 		his_tty = "";
104 	get_addrs(my_machine_name, his_machine_name);
105 	/*
106 	 * Initialize the message template.
107 	 */
108 	msg.vers = TALK_VERSION;
109 	msg.addr.sa_family = htons(AF_INET);
110 	msg.ctl_addr.sa_family = htons(AF_INET);
111 	msg.id_num = htonl(0);
112 	strncpy(msg.l_name, my_name, NAME_SIZE);
113 	msg.l_name[NAME_SIZE - 1] = '\0';
114 	strncpy(msg.r_name, his_name, NAME_SIZE);
115 	msg.r_name[NAME_SIZE - 1] = '\0';
116 	strncpy(msg.r_tty, his_tty, TTY_SIZE);
117 	msg.r_tty[TTY_SIZE - 1] = '\0';
118 }
119