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
usage(void)39 usage(void)
40 {
41 (void)fprintf(stderr, "usage: logname\n");
42 exit(1);
43 }
44
45 int
main(int argc,char * argv[])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