hostname.c revision 1556 
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 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
41static char sccsid[] = "@(#)hostname.c	8.1 (Berkeley) 5/31/93";
42#endif /* not lint */
43
44#include <sys/param.h>
45
46#include <err.h>
47#include <stdio.h>
48#include <stdlib.h>
49#include <string.h>
50#include <unistd.h>
51
52int
53main(argc,argv)
54	int argc;
55	char *argv[];
56{
57	extern int optind;
58	int ch, sflag;
59	char *p, hostname[MAXHOSTNAMELEN];
60
61	sflag = 0;
62	while ((ch = getopt(argc, argv, "s")) != EOF)
63		switch (ch) {
64		case 's':
65			sflag = 1;
66			break;
67		case '?':
68		default:
69			(void)fprintf(stderr,
70			    "usage: hostname [-s] [hostname]\n");
71			exit(1);
72		}
73	argc -= optind;
74	argv += optind;
75
76	if (*argv) {
77		if (sethostname(*argv, strlen(*argv)))
78			err(1, "sethostname");
79	} else {
80		if (gethostname(hostname, sizeof(hostname)))
81			err(1, "gethostname");
82		if (sflag && (p = strchr(hostname, '.')))
83			*p = '\0';
84		(void)printf("%s\n", hostname);
85	}
86	exit(0);
87}
88