xref: /freebsd/bin/domainname/domainname.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/param.h>
33 
34 #include <err.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 
40 static void usage(void) __dead2;
41 
42 int
43 main(int argc, char *argv[])
44 {
45 	int ch;
46 	char domainname[MAXHOSTNAMELEN];
47 
48 	while ((ch = getopt(argc, argv, "")) != -1)
49 		switch (ch) {
50 		case '?':
51 			/* fall through */
52 		default:
53 			usage();
54 		}
55 	argc -= optind;
56 	argv += optind;
57 
58 	if (argc > 1)
59 		usage();
60 
61 	if (*argv) {
62 		if (setdomainname(*argv, (int)strlen(*argv)))
63 			err(1, "setdomainname");
64 	} else {
65 		if (getdomainname(domainname, (int)sizeof(domainname)))
66 			err(1, "getdomainname");
67 		(void)printf("%s\n", domainname);
68 	}
69 	exit(0);
70 }
71 
72 static void
73 usage(void)
74 {
75 	(void)fprintf(stderr, "usage: domainname [ypdomain]\n");
76 	exit(1);
77 }
78