xref: /openbsd/usr.bin/logname/logname.c (revision 404b540a)
1 /*	$OpenBSD: logname.c,v 1.6 2003/06/10 22:20:47 deraadt 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 #ifndef lint
34 static char copyright[] =
35 "@(#) Copyright (c) 1991, 1993, 1994\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)logname.c	8.2 (Berkeley) 4/3/94";
42 #endif
43 static char rcsid[] = "$OpenBSD: logname.c,v 1.6 2003/06/10 22:20:47 deraadt Exp $";
44 #endif /* not lint */
45 
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <locale.h>
49 #include <unistd.h>
50 #include <err.h>
51 
52 void usage(void);
53 
54 int
55 main(int argc, char *argv[])
56 {
57 	int ch;
58 	char *p;
59 
60 	setlocale(LC_ALL, "");
61 
62 	while ((ch = getopt(argc, argv, "")) != -1)
63 		switch (ch) {
64 		case '?':
65 		default:
66 			usage();
67 			/* NOTREACHED */
68 		}
69 
70 	if (argc != optind) {
71 		usage();
72 		/* NOTREACHED */
73 	}
74 
75 	if ((p = getlogin()) == NULL)
76 		err(1, NULL);
77 	(void)printf("%s\n", p);
78 	exit(0);
79 }
80 
81 void
82 usage(void)
83 {
84 	(void)fprintf(stderr, "usage: logname\n");
85 	exit(1);
86 }
87