1 /* $OpenBSD: logname.c,v 1.10 2016/10/13 11:51:02 schwarze Exp $ */ 2 /* $NetBSD: logname.c,v 1.6 1994/12/22 06:39:32 jtc Exp $ */ 3 4 /*- 5 * Copyright (c) 1991, 1993, 1994 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 <err.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <unistd.h> 37 38 static void __dead 39 usage(void) 40 { 41 (void)fprintf(stderr, "usage: logname\n"); 42 exit(1); 43 } 44 45 int 46 main(int argc, char *argv[]) 47 { 48 int ch; 49 char *p; 50 51 if (pledge("stdio", NULL) == -1) 52 err(1, "pledge"); 53 54 while ((ch = getopt(argc, argv, "")) != -1) 55 switch (ch) { 56 default: 57 usage(); 58 } 59 60 if (argc != optind) 61 usage(); 62 63 if ((p = getlogin()) == NULL) 64 err(1, NULL); 65 66 (void)printf("%s\n", p); 67 return 0; 68 } 69