hostname/hostname.c

   1 /*      $NetBSD: hostname.c,v 1.13 1998/07/28 05:31:24 mycroft 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. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 #ifndef lint
  38 __COPYRIGHT("@(#) Copyright (c) 1988, 1993\n\
  39         The Regents of the University of California.  All rights reserved.\n");
  40 #endif /* not lint */
  41
  42 #ifndef lint
  43 #if 0
  44 static char sccsid[] = "@(#)hostname.c  8.2 (Berkeley) 4/28/95";
  45 #else
  46 __RCSID("$NetBSD: hostname.c,v 1.13 1998/07/28 05:31:24 mycroft Exp $");
  47 #endif
  48 #endif /* not lint */
  49
  50 #include <sys/param.h>
  51
  52 #include <err.h>
  53 #include <stdio.h>
  54 #include <stdlib.h>
  55 #include <string.h>
  56 #include <unistd.h>
  57
  58 void usage __P((void));
  59 int main __P((int, char *[]));
  60
  61 int
  62 main(argc, argv)
  63         int argc;
  64         char *argv[];
  65 {
  66         int ch, sflag;
  67         char *p, hostname[MAXHOSTNAMELEN + 1];
  68
  69         sflag = 0;
  70         while ((ch = getopt(argc, argv, "s")) != -1)
  71                 switch (ch) {
  72                 case 's':
  73                         sflag = 1;
  74                         break;
  75                 case '?':
  76                 default:
  77                         usage();
  78                 }
  79         argc -= optind;
  80         argv += optind;
  81
  82         if (argc > 1)
  83                 usage();
  84
  85         if (*argv) {
  86                 if (sethostname(*argv, strlen(*argv)))
  87                         err(1, "sethostname");
  88         } else {
  89                 if (gethostname(hostname, sizeof(hostname)))
  90                         err(1, "gethostname");
  91                 hostname[sizeof(hostname) - 1] = '\0';
  92                 if (sflag && (p = strchr(hostname, '.')))
  93                         *p = '\0';
  94                 (void)printf("%s\n", hostname);
  95         }
  96         exit(0);
  97         /* NOTREACHED */
  98 }
  99
 100 void
 101 usage()
 102 {
 103
 104         (void)fprintf(stderr, "usage: hostname [-s] [name-of-host]\n");
 105         exit(1);
 106         /* NOTREACHED */
 107 }