lib/libc/gen/gethostname.c

   1 /*
   2  * Copyright (c) 1989, 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  * 3. 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  * @(#)gethostname.c    8.1 (Berkeley) 6/4/93
  30  * $FreeBSD: src/lib/libc/gen/gethostname.c,v 1.8 2007/01/09 00:27:54 imp Exp $
  31  * $DragonFly: src/lib/libc/gen/gethostname.c,v 1.4 2005/11/19 22:32:53 swildner Exp $
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/sysctl.h>
  36
  37 #include <errno.h>
  38 #include <unistd.h>
  39
  40 int
  41 gethostname(char *name, size_t namelen)
  42 {
  43         int mib[2];
  44
  45         mib[0] = CTL_KERN;
  46         mib[1] = KERN_HOSTNAME;
  47         if (sysctl(mib, 2, name, &namelen, NULL, 0) == -1) {
  48                 if (errno == ENOMEM)
  49                         errno = ENAMETOOLONG;
  50                 return (-1);
  51         }
  52         return (0);
  53 }