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get_names.c revision 1.9 
      1 /*	$NetBSD: get_names.c,v 1.9 2001/04/06 11:13:46 wiz 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 1.9 2001/04/06 11:13:46 wiz Exp $");
     42 #endif /* not lint */
     43 
     44 #include "talk.h"
     45 #include <sys/param.h>
     46 #include <pwd.h>
     47 #include <stdlib.h>
     48 #include <unistd.h>
     49 
     50 extern	CTL_MSG msg;
     51 
     52 /*
     53  * Determine the local and remote user, tty, and machines
     54  */
     55 void
     56 get_names(argc, argv)
     57 	int argc;
     58 	char *argv[];
     59 {
     60 	char hostname[MAXHOSTNAMELEN + 1];
     61 	const char *his_name, *my_name;
     62 	const char *my_machine_name, *his_machine_name;
     63 	char *his_tty;
     64 	char *cp;
     65 	char *names;
     66 
     67 	if (argc < 2 ) {
     68 		printf("Usage: talk user [ttyname]\n");
     69 		exit(1);
     70 	}
     71 	if (!isatty(0)) {
     72 		printf("Standard input must be a tty, not a pipe or a file\n");
     73 		exit(1);
     74 	}
     75 	if ((my_name = getlogin()) == NULL) {
     76 		struct passwd *pw;
     77 
     78 		if ((pw = getpwuid(getuid())) == NULL) {
     79 			printf("You don't exist. Go away.\n");
     80 			exit(1);
     81 		}
     82 		my_name = pw->pw_name;
     83 	}
     84 	gethostname(hostname, sizeof (hostname));
     85 	hostname[sizeof(hostname) - 1] = '\0';
     86 	my_machine_name = hostname;
     87 	/* check for, and strip out, the machine name of the target */
     88 	names = strdup(argv[1]);
     89 	for (cp = names; *cp && !strchr("@:!.", *cp); cp++)
     90 		;
     91 	if (*cp == '\0') {
     92 		/* this is a local to local talk */
     93 		his_name = names;
     94 		his_machine_name = my_machine_name;
     95 	} else {
     96 		if (*cp++ == '@') {
     97 			/* user@host */
     98 			his_name = names;
     99 			his_machine_name = cp;
    100 		} else {
    101 			/* host.user or host!user or host:user */
    102 			his_name = cp;
    103 			his_machine_name = names;
    104 		}
    105 		*--cp = '\0';
    106 	}
    107 	if (argc > 2)
    108 		his_tty = argv[2];	/* tty name is arg 2 */
    109 	else
    110 		his_tty = "";
    111 	get_addrs(my_machine_name, his_machine_name);
    112 	/*
    113 	 * Initialize the message template.
    114 	 */
    115 	msg.vers = TALK_VERSION;
    116 	msg.addr.sa_family = htons(AF_INET);
    117 	msg.ctl_addr.sa_family = htons(AF_INET);
    118 	msg.id_num = htonl(0);
    119 	strncpy(msg.l_name, my_name, NAME_SIZE);
    120 	msg.l_name[NAME_SIZE - 1] = '\0';
    121 	strncpy(msg.r_name, his_name, NAME_SIZE);
    122 	msg.r_name[NAME_SIZE - 1] = '\0';
    123 	strncpy(msg.r_tty, his_tty, TTY_SIZE);
    124 	msg.r_tty[TTY_SIZE - 1] = '\0';
    125 }
    126