hostname.c revision 99109 
1/*
2 * Copyright (c) 1988, 1993
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
34#ifndef lint
35static char const copyright[] =
36"@(#) Copyright (c) 1988, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41#if 0
42static char sccsid[] = "@(#)hostname.c	8.1 (Berkeley) 5/31/93";
43#endif
44#endif /* not lint */
45#include <sys/cdefs.h>
46__FBSDID("$FreeBSD: head/bin/hostname/hostname.c 99109 2002-06-30 05:13:54Z obrien $");
47
48#include <sys/param.h>
49
50#include <err.h>
51#include <stdio.h>
52#include <stdlib.h>
53#include <string.h>
54#include <unistd.h>
55
56void usage(void);
57
58int
59main(int argc, char *argv[])
60{
61	int ch, sflag;
62	char *p, hostname[MAXHOSTNAMELEN];
63
64	sflag = 0;
65	while ((ch = getopt(argc, argv, "s")) != -1)
66		switch (ch) {
67		case 's':
68			sflag = 1;
69			break;
70		case '?':
71		default:
72			usage();
73		}
74	argc -= optind;
75	argv += optind;
76
77	if (argc > 1)
78		usage();
79
80	if (*argv) {
81		if (sethostname(*argv, (int)strlen(*argv)))
82			err(1, "sethostname");
83	} else {
84		if (gethostname(hostname, (int)sizeof(hostname)))
85			err(1, "gethostname");
86		if (sflag) {
87			p = strchr(hostname, '.');
88			if (p != NULL)
89				*p = '\0';
90		}
91		(void)printf("%s\n", hostname);
92	}
93	exit(0);
94}
95
96void
97usage(void)
98{
99
100	(void)fprintf(stderr, "usage: hostname [-s] [name-of-host]\n");
101	exit(1);
102}
103