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hostname.c revision 1.21 
      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
     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
     95 usage(void)
     96 {
     97 	(void)fprintf(stderr, "usage: %s [-s] [name-of-host]\n",
     98 	    getprogname());
     99 	exit(1);
    100 	/* NOTREACHED */
    101 }
    102