1 /* 2 * Copyright (c) 1988, 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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#) Copyright (c) 1988, 1993 The Regents of the University of California. All rights reserved. 30 * @(#)tty.c 8.1 (Berkeley) 6/6/93 31 * $FreeBSD: src/usr.bin/tty/tty.c,v 1.4.2.1 2001/07/30 10:16:47 dd Exp $ 32 * $DragonFly: src/usr.bin/tty/tty.c,v 1.4 2004/12/23 15:17:21 liamfoy Exp $ 33 */ 34 35 #include <stdio.h> 36 #include <stdlib.h> 37 #include <unistd.h> 38 39 static void usage(void); 40 41 int 42 main(int argc, char **argv) 43 { 44 int ch, sflag; 45 char *t; 46 47 sflag = 0; 48 while ((ch = getopt(argc, argv, "s")) != -1) 49 switch(ch) { 50 case 's': 51 sflag = 1; 52 break; 53 case '?': 54 default: 55 usage(); 56 } 57 58 t = ttyname(0); 59 if (!sflag) 60 puts(t ? t : "not a tty"); 61 exit(t ? 0 : 1); 62 } 63 64 static void 65 usage(void) 66 { 67 fprintf(stderr, "usage: tty [-s]\n"); 68 exit(2); 69 } 70