xref: /netbsd-src/usr.bin/talk/get_names.c (revision 4472dbe5e3bd91ef2540bada7a7ca7384627ff9b)
1 /*	$NetBSD: get_names.c,v 1.7 1998/07/26 22:26:29 mycroft Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)get_names.c	8.1 (Berkeley) 6/6/93";
40 #endif
41 __RCSID("$NetBSD: get_names.c,v 1.7 1998/07/26 22:26:29 mycroft Exp $");
42 #endif /* not lint */
43 
44 #include "talk.h"
45 #include <sys/param.h>
46 #include <pwd.h>
47 #include <unistd.h>
48 
49 extern	CTL_MSG msg;
50 
51 /*
52  * Determine the local and remote user, tty, and machines
53  */
54 void
55 get_names(argc, argv)
56 	int argc;
57 	char *argv[];
58 {
59 	char hostname[MAXHOSTNAMELEN + 1];
60 	const char *his_name, *my_name;
61 	const char *my_machine_name, *his_machine_name;
62 	char *his_tty;
63 	char *cp;
64 	char *names;
65 
66 	if (argc < 2 ) {
67 		printf("Usage: talk user [ttyname]\n");
68 		exit(-1);
69 	}
70 	if (!isatty(0)) {
71 		printf("Standard input must be a tty, not a pipe or a file\n");
72 		exit(-1);
73 	}
74 	if ((my_name = getlogin()) == NULL) {
75 		struct passwd *pw;
76 
77 		if ((pw = getpwuid(getuid())) == NULL) {
78 			printf("You don't exist. Go away.\n");
79 			exit(-1);
80 		}
81 		my_name = pw->pw_name;
82 	}
83 	gethostname(hostname, sizeof (hostname));
84 	hostname[sizeof(hostname) - 1] = '\0';
85 	my_machine_name = hostname;
86 	/* check for, and strip out, the machine name of the target */
87 	names = strdup(argv[1]);
88 	for (cp = names; *cp && !strchr("@:!.", *cp); cp++)
89 		;
90 	if (*cp == '\0') {
91 		/* this is a local to local talk */
92 		his_name = names;
93 		his_machine_name = my_machine_name;
94 	} else {
95 		if (*cp++ == '@') {
96 			/* user@host */
97 			his_name = names;
98 			his_machine_name = cp;
99 		} else {
100 			/* host.user or host!user or host:user */
101 			his_name = cp;
102 			his_machine_name = names;
103 		}
104 		*--cp = '\0';
105 	}
106 	if (argc > 2)
107 		his_tty = argv[2];	/* tty name is arg 2 */
108 	else
109 		his_tty = "";
110 	get_addrs(my_machine_name, his_machine_name);
111 	/*
112 	 * Initialize the message template.
113 	 */
114 	msg.vers = TALK_VERSION;
115 	msg.addr.sa_family = htons(AF_INET);
116 	msg.ctl_addr.sa_family = htons(AF_INET);
117 	msg.id_num = htonl(0);
118 	strncpy(msg.l_name, my_name, NAME_SIZE);
119 	msg.l_name[NAME_SIZE - 1] = '\0';
120 	strncpy(msg.r_name, his_name, NAME_SIZE);
121 	msg.r_name[NAME_SIZE - 1] = '\0';
122 	strncpy(msg.r_tty, his_tty, TTY_SIZE);
123 	msg.r_tty[TTY_SIZE - 1] = '\0';
124 }
125