hostname.c revision 26403 
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 *	$Id: hostname.c,v 1.6 1997/03/28 15:24:20 imp Exp $
34 */
35
36#ifndef lint
37static char const copyright[] =
38"@(#) Copyright (c) 1988, 1993\n\
39	The Regents of the University of California.  All rights reserved.\n";
40#endif /* not lint */
41
42#ifndef lint
43static char const sccsid[] = "@(#)hostname.c	8.1 (Berkeley) 5/31/93";
44#endif /* not lint */
45
46#include <sys/param.h>
47
48#include <err.h>
49#include <stdio.h>
50#include <stdlib.h>
51#include <string.h>
52#include <unistd.h>
53
54extern char *__progname;
55
56void usage __P((void));
57
58int
59main(argc,argv)
60	int argc;
61	char *argv[];
62{
63	int ch, sflag;
64	char *p, hostname[MAXHOSTNAMELEN];
65
66	sflag = 0;
67	while ((ch = getopt(argc, argv, "s")) != -1)
68		switch (ch) {
69		case 's':
70			sflag = 1;
71			break;
72		case '?':
73		default:
74			usage();
75		}
76	argc -= optind;
77	argv += optind;
78
79	if (argc > 1)
80		usage();
81
82	if (*argv) {
83		if (sethostname(*argv, strlen(*argv)))
84			err(1, "sethostname");
85	} else {
86		if (gethostname(hostname, sizeof(hostname)))
87			err(1, "gethostname");
88		if (sflag && (p = strchr(hostname, '.')))
89			*p = '\0';
90		(void)printf("%s\n", hostname);
91	}
92	exit(0);
93}
94
95void
96usage()
97{
98
99	(void)fprintf(stderr, "usage: %s [-s] [name-of-host]\n", __progname);
100	exit(1);
101}
102