1 /*	$OpenBSD: hostname.c,v 1.7 2003/06/02 23:32:08 millert 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 #ifndef lint
34 static char copyright[] =
35 "@(#) Copyright (c) 1988, 1993\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)hostname.c	8.2 (Berkeley) 4/28/95";
42 #else
43 static char rcsid[] = "$OpenBSD: hostname.c,v 1.7 2003/06/02 23:32:08 millert Exp $";
44 #endif
45 #endif /* not lint */
46 
47 #include <sys/param.h>
48 
49 #include <err.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 extern	char *__progname;
56 
57 void usage(void);
58 
59 int
main(int argc,char * argv[])60 main(int argc, char *argv[])
61 {
62 	int ch, sflag;
63 	char *p, hostname[MAXHOSTNAMELEN];
64 
65 	sflag = 0;
66 	while ((ch = getopt(argc, argv, "s")) != -1)
67 		switch (ch) {
68 		case 's':
69 			sflag = 1;
70 			break;
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, strlen(*argv)))
82 			err(1, "sethostname");
83 	} else {
84 		if (gethostname(hostname, sizeof(hostname)))
85 			err(1, "gethostname");
86 		if (sflag && (p = strchr(hostname, '.')))
87 			*p = '\0';
88 		(void)printf("%s\n", hostname);
89 	}
90 	exit(0);
91 }
92 
93 void
usage(void)94 usage(void)
95 {
96 	(void)fprintf(stderr, "usage: %s [-s] [name-of-host]\n", __progname);
97 	exit(1);
98 }
99