1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 #if 0
33 #ifndef lint
34 static char const 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 static char sccsid[] = "@(#)hostname.c 8.1 (Berkeley) 5/31/93";
41 #endif /* not lint */
42 #endif
43 #include <sys/cdefs.h>
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
52 static void usage(void) __dead2;
53
54 int
main(int argc,char * argv[])55 main(int argc, char *argv[])
56 {
57 int ch, sflag, dflag;
58 char hostname[MAXHOSTNAMELEN], *hostp, *p;
59
60 sflag = 0;
61 dflag = 0;
62 while ((ch = getopt(argc, argv, "fsd")) != -1)
63 switch (ch) {
64 case 'f':
65 /*
66 * On Linux, "hostname -f" prints FQDN.
67 * BSD "hostname" always prints FQDN by
68 * default, so we accept but ignore -f.
69 */
70 break;
71 case 's':
72 sflag = 1;
73 break;
74 case 'd':
75 dflag = 1;
76 break;
77 case '?':
78 default:
79 usage();
80 }
81 argc -= optind;
82 argv += optind;
83
84 if (argc > 1 || (sflag && dflag))
85 usage();
86
87 if (*argv) {
88 if (sethostname(*argv, (int)strlen(*argv)))
89 err(1, "sethostname");
90 } else {
91 hostp = hostname;
92 if (gethostname(hostname, (int)sizeof(hostname)))
93 err(1, "gethostname");
94 if (sflag) {
95 p = strchr(hostname, '.');
96 if (p != NULL)
97 *p = '\0';
98 } else if (dflag) {
99 p = strchr(hostname, '.');
100 if (p != NULL)
101 hostp = p + 1;
102 }
103 (void)printf("%s\n", hostp);
104 }
105 exit(0);
106 }
107
108 static void
usage(void)109 usage(void)
110 {
111
112 (void)fprintf(stderr, "usage: hostname [-f] [-s | -d] [name-of-host]\n");
113 exit(1);
114 }
115