1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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 33 #ifndef lint 34 static const char sccsid[] = "@(#)get_names.c 8.1 (Berkeley) 6/6/93"; 35 #endif 36 37 #include <sys/param.h> 38 39 #include <err.h> 40 #include <pwd.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include <unistd.h> 44 45 #include "talk.h" 46 47 extern CTL_MSG msg; 48 49 static void 50 usage(void) 51 { 52 fprintf(stderr, "usage: talk person [ttyname]\n"); 53 exit(1); 54 } 55 56 /* 57 * Determine the local and remote user, tty, and machines 58 */ 59 void 60 get_names(int argc, char *argv[]) 61 { 62 char hostname[MAXHOSTNAMELEN]; 63 char *his_name, *my_name; 64 const char *my_machine_name, *his_machine_name; 65 const char *his_tty; 66 char *cp; 67 68 if (argc < 2 ) 69 usage(); 70 if (!isatty(0)) 71 errx(1, "standard input must be a tty, not a pipe or a file"); 72 if ((my_name = getlogin()) == NULL) { 73 struct passwd *pw; 74 75 if ((pw = getpwuid(getuid())) == NULL) 76 errx(1, "you don't exist. Go away"); 77 my_name = pw->pw_name; 78 } 79 gethostname(hostname, sizeof (hostname)); 80 my_machine_name = hostname; 81 /* check for, and strip out, the machine name of the target */ 82 cp = argv[1] + strcspn(argv[1], "@:!"); 83 if (*cp == '\0') { 84 /* this is a local to local talk */ 85 his_name = argv[1]; 86 my_machine_name = his_machine_name = "localhost"; 87 } else { 88 if (*cp++ == '@') { 89 /* user@host */ 90 his_name = argv[1]; 91 his_machine_name = cp; 92 } else { 93 /* host!user or host:user */ 94 his_name = cp; 95 his_machine_name = argv[1]; 96 } 97 *--cp = '\0'; 98 } 99 if (argc > 2) 100 his_tty = argv[2]; /* tty name is arg 2 */ 101 else 102 his_tty = ""; 103 get_addrs(my_machine_name, his_machine_name); 104 /* 105 * Initialize the message template. 106 */ 107 msg.vers = TALK_VERSION; 108 msg.addr.sa_family = htons(AF_INET); 109 msg.ctl_addr.sa_family = htons(AF_INET); 110 msg.id_num = htonl(0); 111 strlcpy(msg.l_name, my_name, NAME_SIZE); 112 strlcpy(msg.r_name, his_name, NAME_SIZE); 113 strlcpy(msg.r_tty, his_tty, TTY_SIZE); 114 } 115