1 /* $NetBSD: hostname.c,v 1.21 2014/02/13 12:00:29 elric Exp $ */
2
3 /*
4 * Copyright (c) 1988, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1988, 1993\
35 The Regents of the University of California. All rights reserved.");
36 #endif /* not lint */
37
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)hostname.c 8.2 (Berkeley) 4/28/95";
41 #else
42 __RCSID("$NetBSD: hostname.c,v 1.21 2014/02/13 12:00:29 elric Exp $");
43 #endif
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
54 __dead static void usage(void);
55
56 int
main(int argc,char * argv[])57 main(int argc, char *argv[])
58 {
59 int ch, sflag;
60 char *p, hostname[MAXHOSTNAMELEN + 1];
61
62 setprogname(argv[0]);
63 sflag = 0;
64 while ((ch = getopt(argc, argv, "s")) != -1)
65 switch (ch) {
66 case 's':
67 sflag = 1;
68 break;
69 case '?':
70 default:
71 usage();
72 }
73 argc -= optind;
74 argv += optind;
75
76 if (argc > 1)
77 usage();
78
79 if (*argv) {
80 if (sethostname(*argv, strlen(*argv)))
81 err(1, "sethostname");
82 } else {
83 if (gethostname(hostname, sizeof(hostname)))
84 err(1, "gethostname");
85 hostname[sizeof(hostname) - 1] = '\0';
86 if (sflag && (p = strchr(hostname, '.')))
87 *p = '\0';
88 (void)printf("%s\n", hostname);
89 }
90 exit(0);
91 /* NOTREACHED */
92 }
93
94 static void
usage(void)95 usage(void)
96 {
97 (void)fprintf(stderr, "usage: %s [-s] [name-of-host]\n",
98 getprogname());
99 exit(1);
100 /* NOTREACHED */
101 }
102