remote_cmds/talk.tproj/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
  34 #include <sys/cdefs.h>
  35
  36 #ifndef __APPLE__
  37 __FBSDID("$FreeBSD: src/usr.bin/talk/get_names.c,v 1.9 2004/06/14 22:34:13 bms Exp $");
  38
  39 #ifndef lint
  40 static const char sccsid[] = "@(#)get_names.c   8.1 (Berkeley) 6/6/93";
  41 #endif
  42 #endif /* __APPLE__ */
  43
  44 #include <sys/param.h>
  45
  46 #include <err.h>
  47 #include <pwd.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50
  51 #include "talk.h"
  52
  53 extern  CTL_MSG msg;
  54
  55 static void
  56 usage(void)
  57 {
  58         fprintf(stderr, "usage: talk person [ttyname]\n");
  59         exit(1);
  60 }
  61
  62 /*
  63  * Determine the local and remote user, tty, and machines
  64  */
  65 void
  66 get_names(argc, argv)
  67         int argc;
  68         char *argv[];
  69 {
  70         char hostname[MAXHOSTNAMELEN];
  71         char *his_name, *my_name;
  72         char *my_machine_name, *his_machine_name;
  73         const char *his_tty;
  74         char *cp;
  75
  76         if (argc < 2 )
  77                 usage();
  78         if (!isatty(0))
  79                 errx(1, "standard input must be a tty, not a pipe or a file");
  80         if ((my_name = getlogin()) == NULL) {
  81                 struct passwd *pw;
  82
  83                 if ((pw = getpwuid(getuid())) == NULL)
  84                         errx(1, "you don't exist. Go away");
  85                 my_name = pw->pw_name;
  86         }
  87         gethostname(hostname, sizeof (hostname));
  88         my_machine_name = hostname;
  89         /* check for, and strip out, the machine name of the target */
  90         for (cp = argv[1]; *cp && !index("@:!", *cp); cp++)
  91                 ;
  92         if (*cp == '\0') {
  93                 /* this is a local to local talk */
  94                 his_name = argv[1];
  95                 my_machine_name = his_machine_name = "localhost";
  96         } else {
  97                 if (*cp++ == '@') {
  98                         /* user@host */
  99                         his_name = argv[1];
 100                         his_machine_name = cp;
 101                 } else {
 102                         /* host!user or host:user */
 103                         his_name = cp;
 104                         his_machine_name = argv[1];
 105                 }
 106                 *--cp = '\0';
 107         }
 108         if (argc > 2)
 109                 his_tty = argv[2];      /* tty name is arg 2 */
 110         else
 111                 his_tty = "";
 112         get_addrs(my_machine_name, his_machine_name);
 113         /*
 114          * Initialize the message template.
 115          */
 116         msg.vers = TALK_VERSION;
 117         msg.addr.sa_family = htons(AF_INET);
 118         msg.ctl_addr.sa_family = htons(AF_INET);
 119         msg.id_num = htonl(0);
 120         strncpy(msg.l_name, my_name, NAME_SIZE);
 121         msg.l_name[NAME_SIZE - 1] = '\0';
 122         strncpy(msg.r_name, his_name, NAME_SIZE);
 123         msg.r_name[NAME_SIZE - 1] = '\0';
 124         strncpy(msg.r_tty, his_tty, TTY_SIZE);
 125         msg.r_tty[TTY_SIZE - 1] = '\0';
 126 }