xref: /dragonfly/bin/hostname/hostname.c (revision b5744197)
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  * @(#) Copyright (c) 1988, 1993 The Regents of the University of California.  All rights reserved.
34  * @(#)hostname.c	8.1 (Berkeley) 5/31/93
35  * $FreeBSD: src/bin/hostname/hostname.c,v 1.10.2.1 2001/08/01 02:40:23 obrien Exp $
36  * $DragonFly: src/bin/hostname/hostname.c,v 1.4 2003/09/28 14:39:14 hmp Exp $
37  */
38 
39 #include <sys/param.h>
40 
41 #include <err.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 int main (int, char *[]);
48 void usage (void);
49 
50 int
51 main(int argc, char **argv)
52 {
53 	int ch, sflag;
54 	char *p, hostname[MAXHOSTNAMELEN];
55 
56 	sflag = 0;
57 	while ((ch = getopt(argc, argv, "s")) != -1)
58 		switch (ch) {
59 		case 's':
60 			sflag = 1;
61 			break;
62 		case '?':
63 		default:
64 			usage();
65 		}
66 	argc -= optind;
67 	argv += optind;
68 
69 	if (argc > 1)
70 		usage();
71 
72 	if (*argv) {
73 		if (sethostname(*argv, (int)strlen(*argv)))
74 			err(1, "sethostname");
75 	} else {
76 		if (gethostname(hostname, (int)sizeof(hostname)))
77 			err(1, "gethostname");
78 		if (sflag && (p = strchr(hostname, '.')))
79 			*p = '\0';
80 		(void)printf("%s\n", hostname);
81 	}
82 	exit(0);
83 }
84 
85 void
86 usage(void)
87 {
88 
89 	(void)fprintf(stderr, "usage: hostname [-s] [name-of-host]\n");
90 	exit(1);
91 }
92