xref: /freebsd/bin/hostname/hostname.c (revision 84ee9401a3fc8d3c22424266f421a928989cd692)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if 0
31 #ifndef lint
32 static char const copyright[] =
33 "@(#) Copyright (c) 1988, 1993\n\
34 	The Regents of the University of California.  All rights reserved.\n";
35 #endif /* not lint */
36 
37 #ifndef lint
38 static char sccsid[] = "@(#)hostname.c	8.1 (Berkeley) 5/31/93";
39 #endif /* not lint */
40 #endif
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
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 
52 void usage(void);
53 
54 int
55 main(int argc, char *argv[])
56 {
57 	int ch, sflag;
58 	char *p, hostname[MAXHOSTNAMELEN];
59 
60 	sflag = 0;
61 	while ((ch = getopt(argc, argv, "s")) != -1)
62 		switch (ch) {
63 		case 's':
64 			sflag = 1;
65 			break;
66 		case '?':
67 		default:
68 			usage();
69 		}
70 	argc -= optind;
71 	argv += optind;
72 
73 	if (argc > 1)
74 		usage();
75 
76 	if (*argv) {
77 		if (sethostname(*argv, (int)strlen(*argv)))
78 			err(1, "sethostname");
79 	} else {
80 		if (gethostname(hostname, (int)sizeof(hostname)))
81 			err(1, "gethostname");
82 		if (sflag) {
83 			p = strchr(hostname, '.');
84 			if (p != NULL)
85 				*p = '\0';
86 		}
87 		(void)printf("%s\n", hostname);
88 	}
89 	exit(0);
90 }
91 
92 void
93 usage(void)
94 {
95 
96 	(void)fprintf(stderr, "usage: hostname [-s] [name-of-host]\n");
97 	exit(1);
98 }
99