1/*	$OpenBSD: hostname.c,v 1.10 2016/02/01 22:27:25 gsoares Exp $	*/
2/*	$NetBSD: hostname.c,v 1.10 1995/09/07 06:28:40 jtc Exp $	*/
3
4/*
5 * Copyright (c) 1988, 1993
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 <string.h>
37#include <unistd.h>
38#include <limits.h>
39
40extern	char *__progname;
41
42static void __dead usage(void);
43
44int
45main(int argc, char *argv[])
46{
47	int ch, sflag;
48	char *p, hostname[HOST_NAME_MAX+1];
49
50	sflag = 0;
51	while ((ch = getopt(argc, argv, "s")) != -1)
52		switch (ch) {
53		case 's':
54			sflag = 1;
55			break;
56		default:
57			usage();
58		}
59	argc -= optind;
60	argv += optind;
61
62	if (argc > 1)
63		usage();
64
65	if (*argv) {
66		if (sethostname(*argv, strlen(*argv)))
67			err(1, "sethostname");
68	} else {
69		if (gethostname(hostname, sizeof(hostname)))
70			err(1, "gethostname");
71		if (sflag && (p = strchr(hostname, '.')))
72			*p = '\0';
73		(void)printf("%s\n", hostname);
74	}
75	return(0);
76}
77
78static void __dead
79usage(void)
80{
81	(void)fprintf(stderr, "usage: %s [-s] [name-of-host]\n", __progname);
82	exit(1);
83}
84