get_names.c revision 14443
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#ifndef lint 35static char sccsid[] = "@(#)get_names.c 8.1 (Berkeley) 6/6/93"; 36#endif /* not lint */ 37 38#include <unistd.h> 39#include <string.h> 40#include <sys/param.h> 41#include <pwd.h> 42#include "talk.h" 43 44extern CTL_MSG msg; 45 46/* 47 * Determine the local and remote user, tty, and machines 48 */ 49void 50get_names(argc, argv) 51 int argc; 52 char *argv[]; 53{ 54 char hostname[MAXHOSTNAMELEN]; 55 char *his_name, *my_name; 56 char *my_machine_name, *his_machine_name; 57 char *my_tty, *his_tty; 58 register char *cp; 59 60 if (argc < 2 ) { 61 printf("Usage: talk user [ttyname]\n"); 62 exit(-1); 63 } 64 if (!isatty(0)) { 65 printf("Standard input must be a tty, not a pipe or a file\n"); 66 exit(-1); 67 } 68 if ((my_name = getlogin()) == NULL) { 69 struct passwd *pw; 70 71 if ((pw = getpwuid(getuid())) == NULL) { 72 printf("You don't exist. Go away.\n"); 73 exit(-1); 74 } 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 && !index("@:!", *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} 117