usr.bin/talk/get_names.c

   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 1.4 2004/08/30 18:06:50 eirikn 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(int argc, char **argv)
  59 {
  60         char hostname[MAXHOSTNAMELEN];
  61         char *his_name, *my_name;
  62         char *my_machine_name, *his_machine_name;
  63         char *my_tty, *his_tty;
  64         register char *cp;
  65
  66         if (argc < 2 )
  67                 usage();
  68         if (!isatty(0))
  69                 errx(1, "standard input must be a tty, not a pipe or a file");
  70         if ((my_name = getlogin()) == NULL) {
  71                 struct passwd *pw;
  72
  73                 if ((pw = getpwuid(getuid())) == NULL)
  74                         errx(1, "you don't exist. Go away");
  75                 my_name = pw->pw_name;
  76         }
  77         gethostname(hostname, sizeof (hostname));
  78         my_machine_name = hostname;
  79         /* check for, and strip out, the machine name of the target */
  80         for (cp = argv[1]; *cp && !strchr("@:!", *cp); cp++)
  81                 ;
  82         if (*cp == '\0') {
  83                 /* this is a local to local talk */
  84                 his_name = argv[1];
  85                 his_machine_name = my_machine_name;
  86         } else {
  87                 if (*cp++ == '@') {
  88                         /* user@host */
  89                         his_name = argv[1];
  90                         his_machine_name = cp;
  91                 } else {
  92                         /* host!user or host:user */
  93                         his_name = cp;
  94                         his_machine_name = argv[1];
  95                 }
  96                 *--cp = '\0';
  97         }
  98         if (argc > 2)
  99                 his_tty = argv[2];      /* tty name is arg 2 */
 100         else
 101                 his_tty = "";
 102         get_addrs(my_machine_name, his_machine_name);
 103         /*
 104          * Initialize the message template.
 105          */
 106         msg.vers = TALK_VERSION;
 107         msg.addr.sa_family = htons(AF_INET);
 108         msg.ctl_addr.sa_family = htons(AF_INET);
 109         msg.id_num = htonl(0);
 110         strncpy(msg.l_name, my_name, NAME_SIZE);
 111         msg.l_name[NAME_SIZE - 1] = '\0';
 112         strncpy(msg.r_name, his_name, NAME_SIZE);
 113         msg.r_name[NAME_SIZE - 1] = '\0';
 114         strncpy(msg.r_tty, his_tty, TTY_SIZE);
 115         msg.r_tty[TTY_SIZE - 1] = '\0';
 116 }