xref: /dragonfly/usr.bin/logname/logname.c (revision 9bb2a92d)
1 /*-
2  * Copyright (c) 1991, 1993, 1994
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#) Copyright (c) 1991, 1993, 1994 The Regents of the University of California.  All rights reserved.
34  * @(#)logname.c	8.2 (Berkeley) 4/3/94
35  *
36  * $DragonFly: src/usr.bin/logname/logname.c,v 1.3 2003/10/04 20:36:48 hmp Exp $
37  */
38 
39 #include <err.h>
40 #include <errno.h>
41 #include <unistd.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 void usage(void);
47 
48 int
49 main(int argc, char **argv)
50 {
51 	int ch;
52 	char *p;
53 
54 	while ((ch = getopt(argc, argv, "")) != -1)
55 		switch (ch) {
56 		case '?':
57 		default:
58 			usage();
59 		}
60 	argc -= optind;
61 	argv += optind;
62 
63 	if ((p = getlogin()) == NULL)
64 		err(1, NULL);
65 	(void)printf("%s\n", p);
66 	exit(0);
67 }
68 
69 void
70 usage(void)
71 {
72 	(void)fprintf(stderr, "usage: logname\n");
73 	exit(1);
74 }
75