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get_names.c revision 1.14 
      1 /*	$NetBSD: get_names.c,v 1.14 2009/04/13 23:43:36 lukem 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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 #if 0
     35 static char sccsid[] = "@(#)get_names.c	8.1 (Berkeley) 6/6/93";
     36 #endif
     37 __RCSID("$NetBSD: get_names.c,v 1.14 2009/04/13 23:43:36 lukem Exp $");
     38 #endif /* not lint */
     39 
     40 #include "talk.h"
     41 #include <err.h>
     42 #include <sys/param.h>
     43 #include <pwd.h>
     44 #include <stdlib.h>
     45 #include <unistd.h>
     46 #include <util.h>
     47 
     48 extern	CTL_MSG msg;
     49 
     50 /*
     51  * Determine the local and remote user, tty, and machines
     52  */
     53 void
     54 get_names(argc, argv)
     55 	int argc;
     56 	char *argv[];
     57 {
     58 	char hostname[MAXHOSTNAMELEN + 1];
     59 	const char *his_name, *my_name;
     60 	const char *my_machine_name, *his_machine_name;
     61 	const char *his_tty;
     62 	char *cp;
     63 	char *names;
     64 
     65 	if (argc < 2 ) {
     66 		printf("usage: talk user [ttyname]\n");
     67 		exit(1);
     68 	}
     69 	if (!isatty(0)) {
     70 		printf("Standard input must be a tty, not a pipe or a file\n");
     71 		exit(1);
     72 	}
     73 	if ((my_name = getlogin()) == NULL) {
     74 		struct passwd *pw;
     75 
     76 		if ((pw = getpwuid(getuid())) == NULL) {
     77 			printf("You don't exist. Go away.\n");
     78 			exit(1);
     79 		}
     80 		my_name = pw->pw_name;
     81 	}
     82 	if ((cp = getenv("TALKHOST")) != NULL)
     83 		(void)estrlcpy(hostname, cp, sizeof(hostname));
     84 	else {
     85 		if (gethostname(hostname, sizeof(hostname)) == -1)
     86 			err(EXIT_FAILURE, "gethostname");
     87 		hostname[sizeof(hostname) - 1] = '\0';
     88 	}
     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 	free(names);
    129 }
    130