xref: /freebsd/usr.bin/talk/get_names.c (revision a8445737e740901f5f2c8d24c12ef7fc8b00134e)
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
36 static char sccsid[] = "@(#)get_names.c	8.1 (Berkeley) 6/6/93";
37 #endif
38 static const char rcsid[] =
39 	"$Id$";
40 #endif /* not lint */
41 
42 #include <err.h>
43 #include <pwd.h>
44 #include <string.h>
45 #include <sys/param.h>
46 #include "talk.h"
47 
48 extern	CTL_MSG msg;
49 
50 static void
51 usage(void)
52 {
53 	fprintf(stderr, "usage: talk person [ttyname]\n");
54 	exit(1);
55 }
56 
57 /*
58  * Determine the local and remote user, tty, and machines
59  */
60 void
61 get_names(argc, argv)
62 	int argc;
63 	char *argv[];
64 {
65 	char hostname[MAXHOSTNAMELEN];
66 	char *his_name, *my_name;
67 	char *my_machine_name, *his_machine_name;
68 	char *my_tty, *his_tty;
69 	register char *cp;
70 
71 	if (argc < 2 )
72 		usage();
73 	if (!isatty(0))
74 		errx(1, "standard input must be a tty, not a pipe or a file");
75 	if ((my_name = getlogin()) == NULL) {
76 		struct passwd *pw;
77 
78 		if ((pw = getpwuid(getuid())) == NULL)
79 			errx(1, "you don't exist. Go away");
80 		my_name = pw->pw_name;
81 	}
82 	gethostname(hostname, sizeof (hostname));
83 	my_machine_name = hostname;
84 	/* check for, and strip out, the machine name of the target */
85 	for (cp = argv[1]; *cp && !index("@:!", *cp); cp++)
86 		;
87 	if (*cp == '\0') {
88 		/* this is a local to local talk */
89 		his_name = argv[1];
90 		his_machine_name = my_machine_name;
91 	} else {
92 		if (*cp++ == '@') {
93 			/* user@host */
94 			his_name = argv[1];
95 			his_machine_name = cp;
96 		} else {
97 			/* host!user or host:user */
98 			his_name = cp;
99 			his_machine_name = argv[1];
100 		}
101 		*--cp = '\0';
102 	}
103 	if (argc > 2)
104 		his_tty = argv[2];	/* tty name is arg 2 */
105 	else
106 		his_tty = "";
107 	get_addrs(my_machine_name, his_machine_name);
108 	/*
109 	 * Initialize the message template.
110 	 */
111 	msg.vers = TALK_VERSION;
112 	msg.addr.sa_family = htons(AF_INET);
113 	msg.ctl_addr.sa_family = htons(AF_INET);
114 	msg.id_num = htonl(0);
115 	strncpy(msg.l_name, my_name, NAME_SIZE);
116 	msg.l_name[NAME_SIZE - 1] = '\0';
117 	strncpy(msg.r_name, his_name, NAME_SIZE);
118 	msg.r_name[NAME_SIZE - 1] = '\0';
119 	strncpy(msg.r_tty, his_tty, TTY_SIZE);
120 	msg.r_tty[TTY_SIZE - 1] = '\0';
121 }
122