1 /* $OpenBSD: tty.c,v 1.7 2013/11/27 13:32:02 okan Exp $ */ 2 /* $NetBSD: tty.c,v 1.4 1994/12/07 00:46:57 jtc Exp $ */ 3 4 /* 5 * Copyright (c) 1988, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <unistd.h> 36 37 static void usage(void); 38 39 int 40 main(int argc, char *argv[]) 41 { 42 int ch, sflag; 43 char *t; 44 45 sflag = 0; 46 while ((ch = getopt(argc, argv, "s")) != -1) { 47 switch(ch) { 48 case 's': 49 sflag = 1; 50 break; 51 case '?': 52 default: 53 usage(); 54 /* NOTREACHED */ 55 } 56 } 57 58 t = ttyname(STDIN_FILENO); 59 if (!sflag) 60 puts(t ? t : "not a tty"); 61 exit(t ? 0 : 1); 62 } 63 64 65 static void 66 usage(void) 67 { 68 fprintf(stderr, "usage: tty [-s]\n"); 69 exit(2); 70 } 71